RECOMMENDED FOR PUBLICATION

Pursuant to Sixth Circuit I.O.P. 32.1(b)

File Name: 21a0199p.06

UNITED STATES COURT OF APPEALS

FOR THE SIXTH CIRCUIT

ATRICURE, INC.,

Plaintiff-Appellee,

v.

JIAN MENG aka Larry Meng; BEIJING MEDICAL 

SCIENTIFIC CO. LTD. dba Med-Zenith,

Defendants-Appellants.

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No. 19-4067

Appeal from the United States District Court

for the Southern District of Ohio at Cincinnati.

No. 1:19-cv-00054—Michael R. Barrett, District Judge.

Decided and Filed: August 27, 2021

Before: GUY, LARSEN, and MURPHY, Circuit Judges.

_________________

COUNSEL

ON BRIEF: Erik R. Puknys, FINNEGAN, HENDERSON, FARABOW, GARRETT & 

DUNNER, LLP, Palo Alto, California, Daniel J. Donnellon, SEBALY, SHILLITO & DYER, 

Dayton, Ohio, Qingyu Yin, FINNEGAN, HENDERSON, FARABOW, GARRETT & 

DUNNER, LLP, Washington, D.C., for Appellants. Mark A. Nadeau, Cameron A. Fine, DLA 

PIPER LLP (US), Phoenix, Arizona, for Appellee.

MURPHY, J., delivered the opinion of the court in which LARSEN, J., joined. GUY, J. 

(pp. 23–37), delivered a separate dissenting opinion.

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OPINION

_________________

MURPHY, Circuit Judge. The Supreme Court has told lower courts to resolve some 

arbitration-related questions with a “healthy regard” for the Federal Arbitration Act’s “federal 

>
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 2

policy favoring arbitration.” Moses H. Cone Mem’l Hosp. v. Mercury Constr. Corp., 460 U.S. 1, 

24 (1983). In this appeal, the defendants argue that this pro-arbitration presumption should 

permit them to enforce a contract’s arbitration clause even though they were not parties to, or 

third-party beneficiaries of, the contract. At one time, they had strong support for this view. 

Many circuit courts used the federal policy favoring arbitration to broadly enforce arbitration 

contracts in favor of (or against) nonparties under expansive readings of generic common-law 

concepts. See, e.g., Arnold v. Arnold Corp., 920 F.2d 1269, 1281–82 (6th Cir. 1990). Yet the 

Act’s text compels states only to treat arbitration contracts the same way that they treat “any 

contract.” 9 U.S.C. § 2. So the Supreme Court has since held that courts considering whether 

arbitration clauses cover nonparties should neutrally apply the relevant state law that otherwise 

governs. Arthur Andersen LLP v. Carlisle, 556 U.S. 624, 630–32 (2009). The Court did not say 

that any policy favoring arbitration should influence things. We thus see no room for this federal 

“dice-loading” rule of construction to resolve the state-law question. Antonin Scalia, A Matter of 

Interpretation 28 (1997); cf. Encino Motorcars, LLC v. Navarro, 138 S. Ct. 1134, 1142 (2018). 

Instead, we must ask whether Ohio law, when fairly read, permits the defendants to 

enforce the arbitration clause even though they did not sign the contract. The defendants rely on 

two “equitable estoppel” theories and one “agency” theory as their grounds to do so. But their 

first estoppel theory rests on the outdated circuit decisions, which adopted a much broader 

estoppel test than the test applied by the Ohio Supreme Court. And the defendants forfeited their 

second estoppel theory. That said, the district court failed to ask the right question under Ohio 

law when rejecting the defendants’ agency theory. All told, then, while we agree that equitable 

estoppel does not apply, we remand one defendant’s agency claim for further proceedings. We 

thus affirm in part and reverse in part the district court’s order denying a stay of this suit pending 

arbitration.

I

AtriCure, Inc., an Ohio company, has invested millions of dollars and years of research in 

developing medical devices that treat a serious degenerative heart condition known as atrial 

fibrillation or “Afib.” The company sells these devices to hospitals throughout the world. In the 

mid-2000s, it sought to enter the Chinese market. To sell products in China, AtriCure needed a 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 3

Chinese agent. In 2005, Dr. Jian Meng, a Chinese citizen, approached AtriCure about a 

partnership. AtriCure and one of Meng’s companies agreed that this company would secure the 

required government approvals and serve as AtriCure’s exclusive Chinese distributor. The 

parties renewed the same basic agreement each year. AtriCure eventually began to contract with 

Beijing ZenoMed Scientific (“ZenoMed”), a company founded by Meng, to distribute its 

products in China. 

The relationship began to sour in 2015. AtriCure came to believe that another Chinese 

company founded by Meng—Beijing Medical Scientific (“Med-Zenith”)—was attempting to 

market a dangerous knockoff medical device. After confronting Meng, AtriCure opted to 

continue with the relationship because of the significant time and expense required to switch to a 

different exclusive distributor in China. 

In 2016, AtriCure and ZenoMed entered into the “Distribution Agreement” relevant to 

this appeal. The agreement included confidentiality and noncompete clauses protecting 

AtriCure’s proprietary information and barring ZenoMed from competing against it. It also 

included an arbitration clause designating the China International Economic and Trade 

Arbitration Commission as the forum. The clause provided: “Any dispute, controversy or claim 

arising out of, in connection with or relating to this Agreement (or the interpretation, breach, 

termination or validity thereof) shall be resolved through arbitration.” Agreement, R.1-2, 

PageID 47. 

The relationship deteriorated further in 2017 when AtriCure claims to have learned that 

Med-Zenith was attempting to develop other counterfeit devices. AtriCure let the Distribution 

Agreement expire at the end of that year. The company demanded that ZenoMed pay for or 

return its inventory of AtriCure products and abide by the Distribution Agreement’s 

confidentiality and noncompete clauses. 

Receiving no response from ZenoMed, AtriCure took two remedial steps. AtriCure’s 

first step was a federal complaint in Ohio. It brought this suit under the district court’s diversity 

jurisdiction against Meng and Med-Zenith. (It also sued another individual who was not served.) 

AtriCure alleged that Meng and Med-Zenith were improperly manufacturing and selling 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 4

dangerous counterfeit products based on information that they had wrongly acquired from 

ZenoMed. It raised state-law claims of tortious interference with contract, misappropriation of 

trade secrets, unfair competition, deceptive trade practices, fraud, negligent misrepresentation, 

“aiding and abetting,” and “civil conspiracy.” 

AtriCure’s second step was a request for arbitration in China. It invoked the Distribution 

Agreement’s arbitration clause against ZenoMed. In its request for arbitration, AtriCure alleged 

that ZenoMed had breached the agreement in various ways (by, for example, failing to pay for 

the inventory and competing against it). AtriCure also alleged that ZenoMed had conspired with 

Meng and Med-Zenith to steal its intellectual property. 

With AtriCure’s arbitration pending against ZenoMed, Meng and Med-Zenith sought to 

stay the company’s federal lawsuit against them under the Federal Arbitration Act. While Meng 

and Med-Zenith were not parties to the Distribution Agreement between AtriCure and ZenoMed, 

they argued that they could benefit from the agreement’s arbitration clause under equitableestoppel and agency theories. The district court denied their motion. 

The court later granted a preliminary injunction barring Meng and Med-Zenith from 

selling products similar to AtriCure’s. We have since affirmed the preliminary injunction. See 

AtriCure, Inc. v. Meng, 842 F. App’x 974, 979–85 (6th Cir. 2021). 

This appeal concerns the antecedent arbitration question: Should the district court have 

stayed AtriCure’s suit against Meng and Med-Zenith pending arbitration? The Federal 

Arbitration Act gives us jurisdiction over the court’s denial of a stay. 9 U.S.C. § 16(a)(1)(A); 

Arthur Andersen LLP v. Carlisle, 556 U.S. 624, 627 (2009). We generally review such a denial 

de novo. See Albert M. Higley Co. v. N/S Corp., 445 F.3d 861, 863 (6th Cir. 2006). But Meng 

and Med-Zenith raise equitable-estoppel claims on appeal. A circuit split exists over whether 

courts should review the denial of such an equitable claim de novo or for an abuse of discretion. 

See Lenox MacLaren Surgical Corp. v. Medtronic, Inc., 449 F. App’x 704, 707 (10th Cir. 2011) 

(citing cases). We need not take sides in this debate. Even under de novo review, the district 

court correctly rejected Meng and Med-Zenith’s estoppel claims. 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 5

II

A

Meng and Med-Zenith seek to stay this suit based on the Distribution Agreement’s 

arbitration clause. But they did not enter into the agreement. So we must consider when 

nonparties to a contract may nevertheless enforce its arbitration requirement. Our answer starts 

with basic arbitration rules. The Federal Arbitration Act requires a federal court to stay an action 

if a plaintiff has sued on an “issue referable to arbitration” under a written contract. 9 U.S.C. § 3. 

Because the availability of a stay turns on whether an enforceable arbitration contract covers the 

plaintiff’s claims, this “stay” question implicates the Act’s main provision governing the validity 

of arbitration contracts: 9 U.S.C. § 2. See New Prime Inc. v. Oliveira, 139 S. Ct. 532, 537–38 

(2019). 

Section 2 makes covered arbitration agreements “valid, irrevocable, and enforceable, 

save upon such grounds as exist at law or in equity for the revocation of any contract.” 9 U.S.C.

§ 2. This language creates “a body of federal substantive law of arbitrability[.]” Moses H. Cone 

Mem’l Hosp. v. Mercury Constr. Corp., 460 U.S. 1, 24 (1983). One might have read it to adopt a 

uniform federal test that uses the common law of contracts as a guide to whether a “valid” or 

“enforceable” arbitration agreement exists (analogous to the uniform federal test tied to the 

common law of agency that guides whether a person is an “employee” under a federal statute 

using that term). Cf. Nationwide Mut. Ins. Co. v. Darden, 503 U.S. 318, 322–23 (1992). But the 

Court has not read § 2’s language in this way. It has instead held that § 2 incorporates a mix of 

differing state contract-law rules supplemented by various uniform federal arbitration rules. 

The Court starts with a presumption that an arbitration agreement is governed by the 

contract law of the state whose laws otherwise apply to it. See Arthur Andersen, 556 U.S. at 630. 

Did the parties enter into a binding contract? How should a court interpret its language? Do any 

contract-law defenses (like fraud or duress) render the contract unenforceable? These types of 

inquiries are presumptively “question[s] of state law,” Volt Info. Scis., Inc. v. Bd. of Trs. of 

Leland Stanford Junior Univ., 489 U.S. 468, 474 (1989), governed by the relevant state’s 

contract law, First Options of Chi., Inc. v. Kaplan, 514 U.S. 938, 944 (1995); see also Doctor’s 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 6

Assocs., Inc. v. Casarotto, 517 U.S. 681, 686–87 (1996); Mastrobuono v. Shearson Lehman 

Hutton, Inc., 514 U.S. 52, 62–63 & 63 n.9 (1995); Perry v. Thomas, 482 U.S. 483, 492 n.9 

(1987).

But not always. The Court has also read § 2 to superimpose some federal mandates on 

top of its default rule to follow state law. Most notably, it has read § 2’s “saving clause” as 

adopting a federal neutrality rule: States must put “arbitration agreements on an equal footing 

with other contracts” and may not target arbitration for uniquely disfavored treatment. AT&T 

Mobility LLC v. Concepcion, 563 U.S. 333, 339 (2011). They, for example, may not require 

parties to jump through special hoops to enter into arbitration contracts. See Doctor’s Assocs., 

517 U.S. at 683. Nor may they adopt special defenses for those contracts. See Concepcion, 

563 U.S. at 341–42. 

Apart from this neutrality rule, the Court has adopted dueling federal “presumptions” that 

either favor or disfavor arbitration depending on the question. See Blanton v. Domino’s Pizza 

Franchising LLC, 962 F.3d 842, 844 (6th Cir. 2020). Because the Federal Arbitration Act 

evinces a “liberal federal policy favoring arbitration,” the Supreme Court has told lower courts to 

resolve some ambiguities in arbitration contracts in an arbitration-friendly way. Moses H. Cone, 

460 U.S. at 24–25. Suppose, for example, that parties have undisputedly entered into an 

arbitration contract, but the contract is unclear about whether it covers one party’s tort claim 

against the other. In that scenario, courts must interpret the agreement in favor of arbitration, no 

matter how state law would resolve the ambiguity. See Lamps Plus, Inc. v. Varela, 139 S. Ct. 

1407, 1418–19 (2019). 

At the same time, the Court has read the Act to disfavor the arbitration of other questions. 

Id. at 1416–17. The Act makes arbitration “a matter of consent, not coercion,” meaning that a 

party must have voluntarily accepted arbitration before the opposing side can compel it. Volt, 

489 U.S. at 479. Absent an unambiguous agreement, the Court refuses to infer this consent to 

arbitrate “fundamental” questions about the arbitration. Lamps Plus, 139 S. Ct. at 1416–17. 

Suppose, for example, that a contract is ambiguous about whether a court or an arbitrator should 

decide if its arbitration clause covers a party’s tort claim. When that different type of ambiguity 

exists, the Court presumes that the parties left this “gateway” question for the court, not the 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 7

arbitrator. See Henry Schein, Inc. v. Archer & White Sales, Inc., 139 S. Ct. 524, 529–30 (2019). 

The Court likewise presumes that an ambiguous contract does not permit class-based arbitration 

even when a state-law rule would resolve this ambiguity differently. Lamps Plus, 139 S. Ct. at 

1415–19.

B

How does this mix of state and federal rules apply to whether an arbitration contract may 

be enforced by or against nonparties? Courts have struggled with the question over time.

Circuit courts initially treated the question as one of federal arbitration law divorced from 

any state’s contract law. See Crawford Pro. Drugs Inc. v. CVS Caremark Corp., 748 F.3d 249, 

261–62 (5th Cir. 2014); Lawson v. Life of the S. Ins. Co., 648 F.3d 1166, 1170–71 (11th Cir. 

2011). These decisions regularly enforced arbitration contracts in favor of or against nonparties 

based on expansive readings of common-law concepts like equitable estoppel or agency law. 

See Grigson v. Creative Artists Agency L.L.C., 210 F.3d 524, 526–28 (5th Cir. 2000); MS Dealer 

Serv. Corp. v. Franklin, 177 F.3d 942, 947 (11th Cir. 1999); Letizia v. Prudential Bache Secs., 

Inc., 802 F.2d 1185, 1187–88 (9th Cir. 1986). Why did courts read these common-law concepts 

broadly? They believed that the “strong federal policy favoring arbitration” should influence the 

question whether an arbitration contract covered nonparties. Letizia, 802 F.2d at 1188. 

Our decision in Arnold v. Arnold Corp., 920 F.2d 1269 (6th Cir. 1990), fits this mold. 

There, a company’s shareholder sold his shares to the company. Id. at 1271. The purchase 

contract, which was governed by Ohio law, included an arbitration clause. Id. When the 

shareholder later sued the company and its officers, the company compelled arbitration. Id. at 

1272. We held that the officers, who were not parties to the contract, could nevertheless require 

the shareholder to arbitrate his claims against them because they were the company’s agents. Id.

at 1281–82. But we did not look to Ohio agency law to decide when an agent could enforce a 

principal’s contract. Id. Rather, we adopted a broad (seemingly, federal) rule that a company’s 

nonparty agents may invoke an arbitration clause in a company contract as “an outgrowth of the 

strong federal policy favoring arbitration.” Id. at 1281 (quoting Letizia, 802 F.2d at 1188); cf. 

Javitch v. First Union Sec., Inc., 315 F.3d 619, 629 (6th Cir. 2003). 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 8

The Supreme Court jettisoned this federal-common-law approach in Arthur Andersen. 

See 556 U.S. at 630–31. There, nonparties to an investment-management contract sought to use 

“equitable estoppel” to invoke the contract’s arbitration clause and compel the investors to 

arbitrate claims against them. Id. at 626–27. The Court clarified that its default rule to start with 

state law governed this “question of who is bound by” an arbitration clause. Id. at 630. It also 

identified traditional common-law doctrines under which a state might “allow a contract to be 

enforced by or against nonparties,” including “assumption, piercing the corporate veil, alter ego, 

incorporation by reference, third-party beneficiary theories, waiver and estoppel[.]” Id. at 631 

(citation omitted). It then remanded for the lower courts to decide whether the “relevant state 

contract law” allowed the nonparties to enforce the contract in that case. Id. at 632; cf. GE 

Energy Power Conversion Fr. SAS, Corp. v. Outokumpu Stainless USA, LLC, 140 S. Ct. 1637, 

1643–44 (2020). 

After Arthur Andersen, circuit courts have recognized that they now must look to the 

relevant state’s common law to decide when nonparties may enforce (or be bound by) an 

arbitration agreement. See Crawford, 748 F.3d at 261–62 & 262 n.9; see also Neal v. Navient 

Sols., LLC, 978 F.3d 572, 575–76 (8th Cir. 2020) (Ohio law); Halliburton Energy Servs., Inc. v. 

Ironshore Specialty Ins. Co., 921 F.3d 522, 530–31 (5th Cir. 2019) (Texas law); A.D. v. Credit 

One Bank, N.A., 885 F.3d 1054, 1060 (7th Cir. 2018) (Nevada law); In re Henson, 869 F.3d 

1052, 1060 (9th Cir. 2017) (California law); White v. Sunoco, Inc., 870 F.3d 257, 263–65 (3d 

Cir. 2017) (Florida and South Dakota law); Belnap v. Iasis Healthcare, 844 F.3d 1272, 1293 

(10th Cir. 2017) (Utah law); Awuah v. Coverall N. Am., Inc., 703 F.3d 36, 41–44 (1st Cir. 2012) 

(Massachusetts law). To the extent that our decision in Arnold suggested that this issue rested on 

federal common law, its analysis did not survive Arthur Andersen. See Lawson, 648 F.3d at 

1170–71. 

This state-law focus also leaves no room for the federal presumption favoring arbitration 

on which pre-Arthur Andersen decisions relied. Arthur Andersen did not invoke that 

presumption when telling courts to follow state law, describing it as a “vague prescription” in 

passing. 556 U.S. at 630 n.5. In addition, this question does not just ask whether the contract 

should cover a particular claim between two parties who have indisputably consented to 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 9

arbitrate. See First Options, 514 U.S. at 945. The question instead involves parties who 

have not agreed to arbitrate with each other—at least where, as here, neither party claims to be a 

third-party beneficiary with independent contract rights. See id. Because the federal policy 

favoring arbitration applies “only when both parties have consented to and are bound by the 

arbitration clause,” courts have refused to apply it to arbitration claims by or against nonparties. 

Griswold v. Coventry First LLC, 762 F.3d 264, 271 (3d Cir. 2014); see IMA, Inc. v. Columbia 

Hosp. Med. City at Dall., Subsidiary L.P., 1 F.4th 385, 391 (5th Cir. 2021); Jacks v. CMH 

Homes, Inc., 856 F.3d 1301, 1305 (10th Cir. 2017); Rajagopalan v. NoteWorld, LLC, 718 F.3d 

844, 846–47 (9th Cir. 2013) (per curiam); cf. McCarthy v. Azure, 22 F.3d 351, 354–55 (1st Cir. 

1994); West v. Household Life Ins. Co., 867 N.E.2d 868, 872 (Ohio Ct. App. 2007). 

How about the competing federal presumption disfavoring arbitration when “fundamental 

arbitration questions” are at stake? Lamps Plus, 139 S. Ct. at 1416. Might the question whether 

an arbitration contract covers nonparties be such a “fundamental” question requiring 

unambiguous proof before permitting arbitration? One court has suggested as much—at least 

where (unlike here) a party to a contract attempted to enforce an arbitration clause against a 

nonparty. See Taylor v. Ernst & Young, L.L.P., 958 N.E.2d 1203, 1213 (Ohio 2011) (citing First 

Options, 514 U.S. at 945). But Arthur Andersen left no room for this federal presumption either. 

It told courts to follow neutral state-law rules when deciding whether nonparties may enforce or 

be bound by an arbitration contract—without suggesting that the outcome should be influenced 

by any federal policy-laden “thumb on the scale” favoring or disfavoring arbitration. See 556 

U.S. at 630–32.

III

Applying Arthur Andersen here, we must start by identifying the state law that governs. 

In a diversity case, the choice-of-law rules of the state in which a district court sits (here, Ohio) 

tell us the law to pick. See White, 870 F.3d at 263. It is not clear how Ohio courts would resolve 

this choice-of-law question. They follow the Restatement’s choice-of-law rules in contract 

cases. See Ohayon v. Safeco Ins. Co. of Ill., 747 N.E.2d 206, 208–14 (Ohio 2001) 

(discussing Restatement (Second) of Conflicts §§ 187–88 (Am. L. Inst. 1971)). And the 

“Restatement generally respects choice-of-law provisions” in contracts. Wise v. Zwicker & 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 10

Assocs., P.C., 780 F.3d 710, 715 (6th Cir. 2015). That principle would point us to Chinese 

law—the law that the Distribution Agreement incorporates. Yet some courts recognize that a 

contract’s choice-of-law provision should not apply when the dispute involves nonparties who 

did not sign the contract. See, e.g., Henson, 869 F.3d at 1059. Perhaps Ohio courts would find 

these decisions persuasive. 

The parties’ litigation choices allow us to avoid this choice-of-law issue. Meng and MedZenith do not argue for Chinese law; rather, they cite federal cases from around the country 

without giving us their views on the applicable law. To the extent their briefing implies that 

federal common law governs, it conflicts with Arthur Andersen. AtriCure, by comparison, 

argues that Ohio law applies, and Meng and Med-Zenith do not dispute this choice in their reply 

brief. We thus will apply Ohio law without resolving any choice-of-law-questions. See Masco 

Corp. v. Wojcik, 795 F. App’x 424, 427 (6th Cir. 2019). 

In Ohio, a nonparty to a contract generally may not enforce a party’s contractual duties 

unless the contract makes the nonparty an intended (not just an incidental) third-party 

beneficiary. See Hill v. Sonitrol of Sw. Ohio, Inc., 521 N.E.2d 780, 784–86 (Ohio 1988); 

Restatement (Second) of Contracts §§ 302, 315 (Am. L. Inst. 1981). This neutral state-law rule 

generally prevents nonparties from enforcing arbitration clauses unless they are intended thirdparty beneficiaries. See JJ Connor Co. v. Reginella Constr. Co., 2014 WL 4401952, at *3–4 

(Ohio Ct. App. Sept. 2, 2014); West, 867 N.E.2d at 873. Here, although the Distribution 

Agreement’s arbitration clause is broad (it covers claims “relating to” the agreement), the clause 

does not expressly say whether it reaches claims against nonparties. Meng and Med-Zenith thus 

do not argue that this clause gives them enforceable rights as third-party beneficiaries (and we 

need not consider the point). 

Meng and Med-Zenith instead rely on doctrines that do not depend on the arbitration 

clause’s text. They argue that they may compel arbitration under two equitable-estoppel theories 

and one agency theory. We must do our best to predict how the Ohio Supreme Court would 

approach these three theories. See Perry v. Allstate Indem. Co., 953 F.3d 417, 421 (6th Cir. 

2020). 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 11

A. “Intertwined Claims” Estoppel Theory

Meng and Med-Zenith first argue that equitable estoppel requires AtriCure to arbitrate its 

claims against them because those claims are “intertwined” with the Distribution Agreement. 

While the Ohio Supreme Court recognizes a type of equitable estoppel in this setting, the court 

would not apply the doctrine as liberally as Meng and Med-Zenith need.

1

In Ohio, as in most jurisdictions, “equitable estoppel” generally seeks to prevent a party 

from fraudulently “having it both ways.” See Doe v. Archdiocese of Cincinnati, 880 N.E.2d 892, 

894–95 (Ohio 2008); Hortman v. City of Miamisburg, 852 N.E.2d 716, 719–21 (Ohio 2006); see 

generally 4 Williston on Contracts § 8:3 (4th ed.), Westlaw (database updated May 2021); 

Richard Frankel, The Arbitration Clause as Super Contract, 91 Wash. U. L. Rev. 531, 580–81 

(2014). The Ohio Supreme Court has described the doctrine as follows: “[E]stoppel arises when 

one by his acts, representations, or admissions, or by his silence when he ought to speak out, 

intentionally or through culpable negligence induces another to believe certain facts to exist and 

such other rightfully relies and acts on such belief, so that he will be prejudiced if the former is 

permitted to deny the existence of such facts.” State ex rel. Madden v. Windham Exempted Vill. 

Sch. Dist. Bd. of Educ., 537 N.E.2d 646, 649 (Ohio 1989) (citation omitted). In other words, a 

party cannot state that “Fact A” is true when this view of the world serves its purposes (and the 

other side has relied on this fact) but later state that “Fact A” is false when this opposite view of 

the world benefits the party in a different situation (and harms the other side). See Doe, 

880 N.E.2d at 894–95. 

Ohio courts have applied estoppel to contracts. See Karl Oakes, 42 Ohio Jur. 3d Estoppel 

and Waiver §§ 81–83, Westlaw (database updated June 2021). As one example, a party who 

accepts contractual benefits by treating the contract as binding cannot later refuse to undertake 

contractual duties by claiming that it has been terminated. See Wilson v. Beck Energy Corp., 

77 N.E.3d 408, 411–14 (Ohio Ct. App. 2016). As another example, a contracting party who 

accepts one reading of an ambiguous term cannot later posit a contrary reading. See Nat’l City 

Bank of Cleveland v. Citizens Bldg. Co. of Cleveland, 74 N.E.2d 273, 281 (Ohio Ct. App. 1947).
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 12

Similar principles extend to arbitration contracts. If a contracting plaintiff argues that one 

of the contract’s terms binds a nonparty defendant, the plaintiff cannot also argue, chameleonlike, that the contract’s arbitration clause does not apply because the defendant did not sign the 

contract. See I Sports v. IMG Worldwide, Inc., 813 N.E.2d 4, 9 (Ohio Ct. App. 2004). Similarly, 

if a plaintiff who did not sign a contract seeks to enforce its terms against a defendant who did, 

the nonparty plaintiff must accept the contract’s arbitration clause too. See Cleveland-AkronCanton Advert. Coop. v. Physician’s Weight Loss Ctrs. of Am., Inc., 922 N.E.2d 1012, 1016–17 

(Ohio Ct. App. 2009); cf. Gerig v. Kahn, 769 N.E.2d 381, 385–86 (Ohio 2002). Equitable 

estoppel, in short, prevents a party from picking and choosing the contract terms that it alleges 

govern its relationship with the other litigant. “By accepting the benefits” of the contract as 

against that litigant, the party must “accept[] the burdens,” including an arbitration mandate. 

Fawn v. Heritage Mut. Ins. Co., 1997 WL 359322, at *2 (Ohio Ct. App. June 30, 1997). 

(Although estoppel typically requires a party to prove reliance on the conduct or statements of 

the party to be estopped, see Madden, 537 N.E.2d at 649, Ohio courts seem to overlook this 

traditional reliance element in the arbitration setting, but cf. Doe v. Carmel Operator, 160 N.E.3d 

518, 523–26 (Ind. 2021).) 

This view of estoppel goes only so far. To trigger the doctrine, a plaintiff’s claims must 

seek to enforce duties that “arise from the contract containing the arbitration clause,” not from 

other legal sources (such as a statute or tort law). Taylor, 958 N.E.2d at 1213; see Henderson v. 

Laws. Title Ins. Corp., 843 N.E.2d 152, 161 (Ohio 2006). When a plaintiff has not argued 

inconsistently that one term of a contract governs the parties’ relationship while others do not, 

Ohio courts reject estoppel claims. See Taylor, 958 N.E.2d at 1213–14. That is true even if the 

noncontract claims “touch matters” related to the contract. I Sports, 813 N.E.2d at 9 (citation 

omitted). And it is true even if a noncontract claim (say, a negligence claim) depends on 

showing a breach of contract (say, the breach proves the violation of a tort duty of care owed to a 

nonparty). See Church v. Fleishour Homes, Inc., 874 N.E.2d 795, 806–07 (Ohio Ct. App. 2007). 

Two Ohio Supreme Court cases demonstrate these rules. First consider a case that found 

estoppel: Gerig. There, a doctor and hospital entered into an affiliation contract with an 

arbitration clause. 769 N.E.2d at 382, 384. After the doctor’s patients sued him for malpractice, 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 13

they alleged that the doctor’s contract with the hospital compelled it to insure him for $4 million. 

Id. at 383. The patients sought a declaratory judgment against the hospital that their reading of 

this contract was correct. Id. But because their suit effectively sought to enforce the hospital’s 

contractual duties, the court held that the patients must accept the arbitration clause. Id. at 385–

86.

Next consider a case that rejected estoppel: Taylor. There, an insurer contracted with an 

accounting firm to conduct an audit. 958 N.E.2d at 1206. When the insurer became insolvent, a 

liquidator brought a negligence claim against the accounting firm. Id. Because the insurer’s 

contract with the accounting firm included an arbitration clause, the firm argued that the 

liquidator (a nonparty) must arbitrate this tort claim. Id. at 1207. The court disagreed. Id. at 

1213–15. Although the contract imposed a contractual duty to follow generally accepted 

auditing standards, Ohio statutes and regulations (not to mention its tort law) imposed the same 

duty on the accounting firm independent of this contractual duty. Id. The liquidator thus had not 

sought to enforce the contract’s duties but avoid its arbitration clause. Id. It sought to enforce 

the statutory duties. 

This dichotomy shows that equitable estoppel does not apply here. AtriCure’s state-law 

claims do not seek to enforce the Distribution Agreement against Meng and Med-Zenith or rely 

on any theory that they owed contractual duties to AtriCure notwithstanding their nonparty 

status. AtriCure thus has not attempted to “have it both ways” by alleging that some of the 

agreement’s terms bind Meng and Med-Zenith whereas the arbitration clause does not. 

Take AtriCure’s claim that Meng and Med-Zenith tortiously interfered with its contract. 

AtriCure alleges that Med-Zenith (acting through Meng) induced ZenoMed to breach the 

Distribution Agreement by providing Med-Zenith with AtriCure’s proprietary information so 

that Med-Zenith could create dangerous knockoff products. This claim in no way suggests that 

Meng or Med-Zenith owed AtriCure contractual duties. Rather, the claim relies on a standalone 

duty grounded in tort law: Do not intentionally and unjustifiably induce another party to breach 

its contract. See Fred Siegel Co., L.P.A. v. Arter & Hadden, 707 N.E.2d 853, 858 (Ohio 1999). 

To be sure, the claim depends on proving that ZenoMed breached its contractual duties (to 

safeguard AtriCure’s information). See id. But that fact does not trigger estoppel, as an Ohio 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 14

court found for a similar tortious-interference claim involving a contract with an arbitration 

clause. See I Sports, 813 N.E.2d at 9. That is because the claim that ZenoMed breached its 

contractual duties does not “enforce” those duties against Meng or Med-Zenith. The claim seeks 

to enforce tort duties against them. 

Or take AtriCure’s claim that Meng and Med-Zenith misappropriated AtriCure’s trade 

secrets. AtriCure alleges that it provided ZenoMed with trade secrets and that Med-Zenith 

(again acting through Meng) wrongly used those secrets to create the knockoff products. Here 

again, this claim does not seek to hold Meng or Med-Zenith liable on a contractual duty. Rather, 

the claim turns on a statutory duty: Do not acquire a party’s trade secret by “improper means” or 

use the trade secret if you obtained it from a person who had “a duty to maintain its secrecy or 

limit its use[.]” Ohio Rev. Code § 1333.61(B)(1), (2)(b) (defining “misappropriation”). Even if 

ZenoMed’s duty to protect AtriCure’s trade secrets arose from the Distribution Agreement, 

AtriCure does not attempt to enforce that duty against Meng and Med-Zenith. It seeks to enforce 

this statutory duty against them. See Taylor, 958 N.E.2d at 1216. 

We will not belabor the point. The same basic problem affects Meng and Med-Zenith’s 

arguments against all of AtriCure’s claims. They do not allege that AtriCure seeks to hold them 

liable for violating contractual duties. Rather, AtriCure’s claims rely on distinct tort or statutory 

duties. See id. That fact makes estoppel improper in Ohio. 

2

Meng and Med-Zenith do not claim that equitable estoppel would apply under the test we 

have articulated. They instead argue for a much broader test. They assert that estoppel applies 

whenever a plaintiff’s statutory or tort claim “makes reference to” a contract, MS Dealer, 

177 F.3d at 947 (citation omitted), or is “intertwined” with the contract’s subject matter, 

Sourcing Unlimited, Inc. v. Asimco Int’l, Inc., 526 F.3d 38, 47 (1st Cir. 2008); see also Grigson, 

210 F.3d at 527–28; J.J. Ryan & Sons, Inc. v. Rhone Poulenc Textile, S.A., 863 F.2d 315, 320–21 

(4th Cir. 1988). Meng and Med-Zenith justify this test with federal cases that predate Arthur 

Andersen. But those cases were following a federal-common-law approach; they were not 

looking to state common law. Arthur Andersen has since held that we cannot create our own 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 15

body of federal estoppel law. See 556 U.S. at 632; Crawford, 748 F.3d at 261–62. We must 

look to Ohio law.

In that regard, Meng and Med-Zenith’s expansive test conflicts with the narrow way that 

Ohio courts have applied the doctrine. In Taylor, for example, the negligence claim alleged a 

violation of a statutory duty (follow generally accepted auditing standards) that was 

“intertwined” with the subject matter of the contract (which imposed the same duty). See

958 N.E.2d at 1215. Yet the Ohio Supreme Court rejected the estoppel argument. Id. Even 

when tort claims depended on proving a breach of a contract, Ohio’s intermediate appellate 

courts have held, estoppel does not apply as long as the plaintiff has not sought to hold the 

defendant itself to the contractual duties. See Church, 874 N.E.2d at 807; I Sports, 813 N.E.2d at 

9. Although Meng and Med-Zenith suggest that the Ohio Supreme Court would reject these 

lower-court decisions in favor of a broader approach, the decisions better match that court’s 

general view of equitable estoppel’s reason for being. It seeks to regulate fraud, not serve proarbitration goals. See Doe, 880 N.E.2d at 895; cf. Doe, 160 N.E.3d at 524–26; Santich v. VCG 

Holding Corp., 443 P.3d 62, 66 (Colo. 2019); Harvey ex rel. Gladden v. Cumberland Tr. & Inv. 

Co., 532 S.W.3d 243, 271 & n.39 (Tenn. 2017).

That brings us to a related point. The federal decisions invoking estoppel whenever a 

claim relates to a contract do not ground this broad test in anything resembling traditional 

estoppel at common law. See Frankel, supra, at 580–87. While they use the phrase “equitable 

estoppel,” they rest more on the federal policy favoring arbitration and efficiency concerns than 

on a traditional view of that doctrine. See Doe, 160 N.E.3d at 525–26; see, e.g., Grigson, 

210 F.3d at 527–28; MS Dealer, 177 F.3d at 947. But the doctrine is named equitable estoppel, 

not efficiency estoppel. How has a plaintiff sought to inequitably “have it both ways” by raising 

a tort claim relating to a contract if the plaintiff does not seek to enforce the contract? Frankel, 

supra, at 586. These decisions do not say. If anything, the decisions call to mind a remark long 

ago made by Professor Williston: “When a lawyer or a judge does not know what other name to 

give for his decision to decide a case in a certain way, he says there is an estoppel.” Samuel 

Williston, Annual Meeting, 4 A.L.I. Proc. 61, 89 (1926). Their main rationale—the federal 

policy favoring arbitration—also did not survive Arthur Andersen’s holding that state law 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 16

governs. See Rajagopalan, 718 F.3d at 846–47. Perhaps that is why Arthur Andersen seemingly 

agreed with a litigant’s suggestion in that case that the federal courts had been applying equitable 

estoppel too loosely. See 556 U.S. at 632. 

Shifting gears, Meng and Med-Zenith turn to two of our decisions holding that a party 

cannot avoid a broad arbitration clause “simply by renaming its claims so that they appear 

facially outside the scope of the arbitration agreement.” Simon v. Pfizer Inc., 398 F.3d 765, 776 

(6th Cir. 2005) (citing Fazio v. Lehman Bros., Inc., 340 F.3d 386, 395 (6th Cir. 2003)). They 

argue that AtriCure has simply renamed its contract claim against ZenoMed as tort claims 

against them. This argument overlooks that these two cases do not even use the word “estoppel.” 

The cases were interpreting the scope of an arbitration clause for claims between contracting 

parties, not claims involving nonparties. A broad arbitration clause can cover not just contract 

claims but tort claims too, especially considering that the federal presumption favoring 

arbitration applies in this context. See Fazio, 340 F.3d at 395; see also Lamps Plus, 139 S. Ct. at 

1418–19. Yet the expansive test applicable in those circumstances is not the test for nonparties. 

See Taylor, 958 N.E.2d at 1213 n.5. So that test tells us nothing about the Ohio Supreme Court’s 

views on equitable estoppel.

Does it change things, though, that the Ohio Supreme Court’s decisions have involved a 

contracting party attempting to enforce an arbitration clause against a nonparty? Cf. id. This 

case involves the opposite: Nonparties (Meng and Med-Zenith) seek to enforce the arbitration 

clause against a contracting party (AtriCure). We fail to see why the difference matters—at least 

in this case. The difference might matter if, for example, Meng and Med-Zenith sought to prove 

that AtriCure intended for them to be third-party beneficiaries with contract rights under the 

agreement. See West, 867 N.E.2d at 873. A third-party-beneficiary claim would make less sense 

against a nonparty who did not enter into the contract at all (or seek its benefits). But Meng 

and Med-Zenith did not raise such a theory, so we must presume that AtriCure has 

not consented to arbitrate its claims against them. That is why Meng and Med-Zenith rely on an 

outside-the-contract doctrine (estoppel) to coerce AtriCure to arbitrate its claims anyway. 

Whether used against a party or a nonparty to the contract, estoppel exists to compel a 

nonconsenting litigant to the arbitration table because of its inconsistent positions about whether 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 17

the contract’s other terms apply as between the two litigants. Because AtriCure has not sought to 

have it both ways in this required fashion, this version of estoppel does not apply here under 

Ohio law. 

B. “Concerted Misconduct” Estoppel Theory

Meng and Med-Zenith next argue that equitable estoppel should compel AtriCure to 

arbitrate its claims against them because AtriCure alleges that they engaged in “interdependent 

and concerted misconduct” with ZenoMed, a contracting party. MS Dealer, 177 F.3d at 947 

(citation omitted). The Ohio Supreme Court has yet to consider this concerted-misconduct 

version of estoppel, so we must ask whether that court would adopt it. See Perry, 953 F.3d at 

421. 

Different factors point in different directions. On the one hand, some Ohio decisions 

have applied this doctrine or at least referred to it. See Discovery Res., Inc. v. Ernst & Young 

U.S. LLP, 62 N.E.3d 714, 720–21 (Ohio Ct. App. 2016); Fields v. Herrnstein Chrysler, Inc., 

2013 WL 772822, at *6–7 (Ohio Ct. App. Feb. 7, 2013); see also Fries v. Greg G. Wright 220 & 

Sons, LLC, 120 N.E.3d 426, 444 (Ohio Ct. App. 2018); I Sports, 813 N.E.2d at 8–9. 

On the other hand, these decisions contain little reasoning, see, e.g., Discovery Res., 

62 N.E.3d at 720–21, and other state supreme courts have outright rejected this type of claim, see 

In re Merrill Lynch Tr. Co. FSB, 235 S.W.3d 185, 191–95 (Tex. 2007). In addition, the courts 

that accept concerted-misconduct estoppel again fail to identify any traditional common-law 

“analog” that could justify it. See Frankel, supra, at 586 n.229. This theory permits a defendant 

alleged to have jointly engaged in fraud with a contracting party to take advantage of those fraud 

allegations by enforcing an arbitration clause that would not otherwise apply to it. Traditionally, 

however, the alleged fraudster is the one who is supposed to be estopped, not the alleged victim. 

See Doe, 880 N.E.2d at 894–95. Like the broad view of the first estoppel claim, concertedmisconduct estoppel also originates with federal cases applying federal common law and 

asserting that “the federal policy in favor of arbitration” would be “thwarted” without it. See MS 

Dealer, 177 F.3d at 947 (citation omitted). Yet again, these cases are no longer good law after 

Arthur Andersen. See Rajagopalan, 718 F.3d at 846–47; Lawson, 648 F.3d at 1170–71.
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 18

At day’s end, we need not resolve whether the Ohio Supreme Court would accept this 

estoppel claim because Meng and Med-Zenith forfeited it. The district court indicated that Meng 

and Med-Zenith did not raise concerted-misconduct estoppel. See Barany-Snyder v. Weiner, 

539 F.3d 327, 331–32 (6th Cir. 2008). And we do not think their reliance on the first estoppel 

theory preserved this second theory. Under our preservation rules, the two estoppel theories are 

sufficiently distinct that they do not qualify as subsidiary arguments in support of the same 

general “claim.” Compare United States v. Reed, 993 F.3d 441, 453 (6th Cir. 2021), with 

Castellon-Vogel v. Int’l Paper Co., 829 F. App’x 100, 103 (6th Cir. 2020). 

Meng and Med-Zenith do not dispute that the two theories are sufficiently distinct that 

these defendants needed to raise each one in the district court in order to preserve them both on 

appeal. Rather, they ask us to interpret stray statements from their stay motion as actually raising 

concerted-misconduct estoppel. Yet they quote from their motion’s statement of facts; the 

motion’s legal argument advocates only for related-to-the-contract estoppel. A party does not 

preserve an issue in our court by raising it in this “perfunctory” way; the party must connect the 

relevant facts to the relevant law. See, e.g., Lou’s Transp., Inc. v. NLRB, 945 F.3d 1012, 1027 

(6th Cir. 2019); McPherson v. Kelsey, 125 F.3d 989, 995–96 (6th Cir. 1997). And while they 

raised this claim in more detail in their reply brief in the district court, they do not dispute that 

this briefing “came too late” under our well-established law. See Infinity Cap. LLC v. Francis 

David Corp., 851 F. App’x 579, 590 (6th Cir. 2021) (citing Sanborn v. Parker, 629 F.3d 554, 

579 (6th Cir. 2010)). We should not place duties on district courts that we would not impose on 

ourselves. So neither the quoted statements nor the reply statements preserved any 

concerted-misconduct claim.

C. Agency Theory

That leaves Meng and Med-Zenith’s agency claim. They argue that nonparties to a 

contract may enforce arbitration clauses when they are agents of one of the contracting parties. 

The Ohio Supreme Court has not addressed this “agency” theory, so we start with Ohio’s 

intermediate appellate courts. See Perry, 953 F.3d at 421. Those courts follow two competing 

sets of agency principles—one that applies generally and another that applies specifically to 

arbitration. 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 19

As a general matter, Ohio’s intermediate courts adhere to the well-established commonlaw rule that agents do not become contracting parties when they sign a contract on behalf of a 

disclosed principal or perform duties as agents for that principal. See Plain Dealer Publ’g Co. v. 

Worrell, 898 N.E.2d 1009, 1011–14 (Ohio Ct. App. 2008); Perrysburg Township v. Rossford, 

778 N.E.2d 619, 624 (Ohio Ct. App. 2002); Edcom Prods., Inc. v. Wattenmaker Advert., Inc., 

1982 WL 2648, at *4 (Ohio Ct. App. Dec. 23, 1982); Restatement (Third) of Agency § 6.01 

(Am. L. Inst. 2006); 12 Williston on Contracts § 35:34 (4th ed.), Westlaw (database updated 

May 2021); 3 Am. Jur. 2d Agency § 285, Westlaw (database updated May 2021); McCarthy, 

22 F.3d at 356. This traditional rule benefits agents because they avoid contract liability even if 

they cause a breach. Cf. Dobell v. Koch, 16 Ohio App. 41, 43–45 (1921). But the rule burdens 

agents because they have no independent rights under the contract unless they prove that they are 

intended third-party beneficiaries. Cf. State ex rel. Brophy v. City of Cleveland, 49 N.E.2d 175, 

176 (Ohio 1943); Restatement (Third) of Agency § 6.01 cmt. d. 

Yet Ohio’s intermediate courts depart from this approach in the arbitration setting. 

There, the courts hold that agents may enforce arbitration clauses in contracts signed by their 

principals when the other party has sued them for actions taken within the scope of their agency. 

See Rivera v. Rent A Ctr., Inc., 2015 WL 5455882, at *4–6 (Ohio Ct. App. Sept. 17, 2015); 

Zilbert v. Proficio Mortg. Ventures, L.L.C., 2014 WL 1776004, at *7 (Ohio Ct. App. May 1, 

2014); McCaskey v. Sanford-Brown Coll., 2012 WL 1142880, at *3–4 (Ohio Ct. App. Apr. 5, 

2012); Tomovich v. USA Waterproofing & Found. Servs., Inc., 2007 WL 4146772, at *3 (Ohio 

Ct. App. Nov. 26, 2007); Genaw v. Lieb, 2005 WL 435211, at *2–4 (Ohio Ct. App. Feb. 25, 

2005); Terry v. Bishop Homes of Copley, Inc., 2003 WL 1524491, at *5–6 (Ohio Ct. App. Mar. 

26, 2003); Manos v. Vizar, 1997 WL 416402, at *1–2 (Ohio Ct. App. July 9, 1997); see also 

Neal, 978 F.3d at 575–77. Some of these decisions rely on broad arbitration clauses that 

expressly mention agents and so make them third-party beneficiaries. See Rivera, 2015 WL 

5455882, at *3. For the most part, though, the decisions seem to apply a rule that agents can 

invoke their principals’ arbitration contracts whether or not the agents are third-party 

beneficiaries. See Genaw, 2005 WL 435211, at *3–4. 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 20

Where did Ohio’s intermediate courts derive this arbitration-only rule? Early decisions 

cited the federal cases (like our Arnold opinion) that permitted agents to invoke their principals’ 

arbitration agreements. See id. But this pre-Arthur Andersen caselaw was applying a “federal 

rule designed to protect the federal policy favoring arbitration,” not a state common-law rule of 

agency. Grand Wireless, Inc. v. Verizon Wireless, Inc., 748 F.3d 1, 11 (1st Cir. 2014); Pritzker 

v. Merrill Lynch, Pierce, Fenner & Smith, Inc., 7 F.3d 1110, 1121–22 (3d Cir. 1993); Arnold, 

920 F.2d at 1281–82; Letizia, 802 F.2d at 1187–88. The courts reasoned that they would 

frustrate the pro-arbitration policy if they allowed parties to avoid their duty to arbitrate claims 

against the other side by suing its agents instead. See Grand Wireless, 748 F.3d at 11. This 

federal rule thus “treats arbitration clauses more favorably than other contract provisions” that 

are governed by the traditional agency framework. Frankel, supra, at 574. Yet the federal rule 

can no longer supply the definitive answer now that state law governs. See Arthur Andersen, 

556 U.S. at 632. 

Rather, we must predict whether the Ohio Supreme Court would follow the traditional 

agency rule or the arbitration-specific agency rule. See Perry, 953 F.3d at 421. Nothing would 

prevent it from incorporating the federal pro-arbitration policy into state law—as Ohio’s lower 

courts and some other state courts have done. See Grand Wireless, 748 F.3d at 11. Although the 

Federal Arbitration Act bars states from adopting contract rules that uniquely disfavor 

arbitration, Concepcion, 563 U.S. at 339, it does not prohibit them from singling out arbitration 

for preferential treatment. That said, nothing would prevent the Ohio Supreme Court from 

jettisoning this federal doctrine as a matter of state law by neutrally following the traditional 

agency approach—as other state courts have noted. See Landry v. Transworld Sys. Inc., 

149 N.E.3d 781, 787 (Mass. 2020); cf. Jeffrey S. Sutton, 51 Imperfect Solutions 28 (2018). 

Ultimately, though, we opt not to guess which rule the Ohio Supreme Court would choose. 

AtriCure has not sufficiently raised any argument that the Ohio Supreme Court would reject the

pro-arbitration approach that Ohio’s lower courts have adopted in favor of the traditional agency 

rule. We thus will assume that this broader pro-arbitration approach applies here.

AtriCure raises a different response to this agency claim. Even the broader arbitrationspecific agency rule does not permit an agent to enforce a principal’s arbitration clause in all
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 21

circumstances. The rule kicks in only if the agent has been sued for conduct that “arose out of 

the agency relationship,” not for conduct that arose outside that relationship. Genaw, 2005 WL 

435211, at *3–4; see Arnold, 920 F.2d at 1282. AtriCure argues on appeal that it does not seek 

to hold Meng and Med-Zenith liable for actions that they took as agents of ZenoMed. This 

agency question has an easy answer for one defendant but a more difficult one for the other. 

Med-Zenith presents the easy answer. Neither party has ever claimed that Med-Zenith 

acted as an agent of ZenoMed in any way. Med-Zenith thus may not rely on any agency theory 

even under the broader arbitration-specific approach to agency law.

Meng presents the difficult answer. Does AtriCure’s suit seek to hold him liable for 

alleged actions that he took as an agent of ZenoMed, as an agent of Med-Zenith, or both? Unlike 

in the typical case in which an employee has one employer and the employee’s challenged 

conduct was clearly within the scope of employment, cf. Arnold, 920 F.2d at 1282, agency 

principles paint a more complex picture when an agent serves different roles for different 

principals, cf. Restatement (Third) of Agency § 3.14 & cmt. c; id. § 7.03. Claims of intentional 

misconduct (like some of the claims here) may complicate things further. See, e.g., Auer v. 

Paliath, 17 N.E.3d 561, 566 (Ohio 2014) (citing Restatement (Third) of Agency § 7.07). Yet the 

parties did not identify the governing agency principles that they believe apply under Ohio law in 

this more complex setting. 

In addition, the Ohio Supreme Court has held that whether an agent acted within the 

scope of its agency relationship with a principal raises a fact question. See id. at 565–66. But 

the district court did not address the question. It rejected Meng’s agency claim solely on the 

ground that AtriCure “does not bring its claims against Defendant Meng in an attempt to avoid 

the Agreement’s arbitration provision.” Op., R.52, PageID 1313–14. That conclusion answered 

the wrong question under the Ohio cases that we apply here. The critical question is not whether 

AtriCure sought to avoid the arbitration agreement; it is whether Meng acted as a ZenoMed 

agent when he engaged in the conduct that AtriCure complains about in this suit (as compared to 

the conduct that it complains about in the separate arbitration against ZenoMed). 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 22

On appeal, the parties essentially ask us to engage in this fact-finding ourselves. Like the 

Seventh Circuit in a similar situation, however, we find it prudent to give the district court the 

initial opportunity to consider this agency question. See Janiga v. Questar Cap. Corp., 615 F.3d 

735, 743–44 (7th Cir. 2010). On remand, we also leave for the parties to consider the proper 

way to resolve this agency question in the context of a motion to stay under 9 U.S.C. § 3 rather 

than a motion to compel under 9 U.S.C. § 4. Cf. Boykin v. Fam. Dollar Stores of Mich., LLC, 

3 F.4th 832, 836–38, 844 (6th Cir. 2021); J & R Sportswear & Co. v. Bobbie Brooks, Inc., 

611 F.2d 29, 30 (3d Cir. 1979). We express no view on these questions. 

* * *

In sum, the district court correctly rejected Meng and Med-Zenith’s attempts to equitably 

estop AtriCure from litigating its claims in court instead of arbitration. The court also correctly 

rejected any agency claim by Med-Zenith. But we remand for the court to consider whether 

Meng acted as a ZenoMed agent under Ohio law for purposes of AtriCure’s claims against him 

in federal court. We affirm in part, reverse in part, and remand for proceedings consistent with 

this opinion.
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 23

_________________

DISSENT

_________________

RALPH B. GUY, JR., Circuit Judge, dissenting. Defendants Jian Meng and Med-Zenith 

unambiguously sought a “stay under Section 3 of the [Federal Arbitration Act]” (FAA). (R. 43, 

PageID 1178); 9 U.S.C. § 3. We cannot ignore AtriCure’s allegations in the complaint and the 

testimony of its executives, nor can we rewrite pro-arbitration state laws under the banner of 

Arthur Andersen LLP v. Carlisle, 556 U.S. 624 (2009). I would reverse and grant a stay pending 

the arbitration in China.

I.

A complete picture of the facts changes the result here. Defendant Meng (or Dr. Meng) 

is a resident of China who owns, or is the president of, several entities. (See R. 32-1, ¶¶ 30-31). 

Meng is a double-agent. AtriCure alleges in its complaint—and its COO testified—that Meng is: 

(1) the “Founder and General Manager” and/or “President of ZenoMed,” a non-party Chinese 

corporation; and (2) the “Founder, President, and CEO” of Med-Zenith, the defendant Chinese 

company. (R. 1, ¶¶ 4, 8; R. 32-1, ¶¶ 6, 8; id., PageID 315 (Meng’s business card that he gave to 

AtriCure in 2014)). The complaint also names a defendant who has not been served, Guanglu 

Bai (Bai or Dr. Bai), who is the “former Director of Research & Development for ZenoMed and 

is currently its legal representative.” (R. 1, ¶ 9). In short, according to AtriCure’s COO, “Dr. 

Meng and Dr. Bai are the primary representatives of ZenoMed.” (R. 32-1, ¶ 5). 

Beginning in 2005, AtriCure entered into a series of exclusive distribution agreements 

with one of Meng’s entities for the distribution and registration of AtriCure’s products in China, 

with annual agreement renewals in the years that followed. (R. 70, PageID 1599; R. 32-1, ¶¶ 15-

17, 31-32). According to AtriCure’s President and CEO, with the way “the partnership had been 

set up,” “all of the registrations” for doing business in China and “all the patents in China” for 

AtriCure’s products were held under the name of one of Meng’s entities or “in his name.” (R. 

70, PageID 1558, 1563-64). AtriCure’s COO also testified that Meng “owned those 

registrations, and [Meng] had . . . everything, soup to nuts, on how [AtriCure’s] devices were 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 24

built.” (R. 71, PageID 1641-42). AtriCure learned that one of Meng’s entities—Med-Zenith—

was creating AtriCure “knock-off” products and confronted Meng. But AtriCure decided to 

continue the relationship because, as AtriCure’s CEO testified, AtriCure “could not sell [its] 

products in China except through [Meng]’s company, ZenoMed.” (R. 70, PageID 1563; R. 1, ¶¶ 

4-5).

On January 1, 2016, AtriCure and ZenoMed entered into the Distribution Agreement at 

issue here. (R. 1, ¶ 20; R. 1-2). The agreement is signed by officers on behalf of AtriCure and 

signed by Bai on behalf of ZenoMed. (R. 1-2, PageID 49). AtriCure’s COO states in his 

affidavit, however, that “Dr. Meng was the primary negotiator and contact point on the 

business relationship between AtriCure and Dr. Meng’s many entities, including during the 2014 

to 2016 period in connection with the parties’ negotiation of the Distribution Agreement.” (R. 

32-1, ¶ 35). AtriCure’s COO also states that “[a]s part of the business relationship between 

AtriCure and ZenoMed, ZenoMed, through its officers Dr. Meng and Dr. Bai, was 

responsible for securing regulatory approvals in China for AtriCure’s products.” (Id., ¶ 17; R. 1, 

¶¶ 44, 80, 93-95).

The Distribution Agreement includes confidentiality and non-compete clauses. (R. 1-2, 

PageID 34, 38). Most notably, the Distribution Agreement also contains a broad, general 

arbitration provision, and provides that “arbitration shall be conducted in Beijing, PRC and 

administered by the China International Economic And Trade Arbitration Commission (the 

“CIETAC”) under the CIETAC Administered Arbitration Rules[.]” (R. 1-2, PageID 47).

In 2017, when AtriCure learned that Med-Zenith was again selling AtriCure knock-offs, 

AtriCure allowed the Distribution Agreement to expire, thereby terminating the agreement. 

(R. 1, ¶ 22). AtriCure sought relief.

AtriCure’s first step was to file this lawsuit against Med-Zenith, Meng, and Bai on 

January 22, 2019. (R. 1). AtriCure asserts eight state law claims: (1) tortious interference with 

business relations; (2) misappropriation of trade secrets; (3) unfair competition; (4) deceptive 

trade practices; (5) fraud; (6) negligent misrepresentation; (7) aiding and abetting; and (8) civil 

conspiracy. 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 25

ZenoMed is not a party to this action. And yet, AtriCure alleges that “ZenoMed has since 

breached the Distribution Agreement in numerous respects[.]” (R. 1, ¶ 3). “Dr. Meng, the 

President of ZenoMed, and his colleague Dr. Bai, were the primary wrongdoers that directed 

and caused ZenoMed’s breaches.” (Id., ¶ 4). “[T]hey engaged in and directed a fraudulent 

scheme in knowingly inducing AtriCure into providing them with its proprietary technology and 

intellectual property, which they then misappropriated in concert with ZenoMed and . . . 

(“Med-Zenith”)[.]” (Id., ¶ 4). “Dr. Meng and Dr. Bai aided and abetted ZenoMed’s 

contractual breaches, facilitated a conspiracy to misappropriate AtriCure’s intellectual property 

and business, perpetrated a fraud upon AtriCure, and tortiously interfered with AtriCure’s 

business.” (Id., ¶ 5). “Dr. Meng and Dr. Bai provided Med-Zenith with AtriCure’s Confidential 

Information and intellectual property obtained in their roles with ZenoMed.” (Id., ¶ 40). 

“Defendants’ misrepresentations were material to AtriCure’s decision to enter into the 

Distribution Agreement and otherwise enter into and continue its business relationship 

with ZenoMed and Defendants, . . . and trust Defendants with such information.” (Id., ¶ 83). 

“Defendants, and each of them, acted in concert together and with ZenoMed and MedZenith, to assist ZenoMed in breaching the Distribution Agreement, assist each other in 

committing fraud and other tortious conduct, and assist Med-Zenith in the theft of AtriCure’s 

intellectual property[.]” (Id., ¶¶ 104, 110). 

That is just a sampling. (Id., ¶¶ 24-25, 37, 39-40, 57, 59, 67, 72, 77, 80, 82-84, 88, 93-96, 

104-05, 110-11). But AtriCure also devotes a portion of the complaint to the specific promises 

ZenoMed made under the Distribution Agreement (including reciting specific provisions), 

ZenoMed’s breaches of those promises, and specifically claims entitlement to $1.1 million that 

ZenoMed owes for inventory received. (Id., ¶¶ 24-34, 93, 80).

Then, on March 19, 2019, AtriCure submitted to the CIETAC (China Arbitration) a 

demand for arbitration with ZenoMed. (R. 43-1, PageID 1190). AtriCure later argued in the 

arbitration that the “disputes all arise out of the Distribution Agreements and fall within the 

scope of dispute resolution matters governed by the arbitration clause in this case.” (ECF No. 

38, Ex. B., ¶ 16, No. 19-4067 (6th Cir. May 22, 2020)). The arbitration demand and the 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 26

complaint here bear an uncanny resemblance. (See, e.g., id., PageID 1191; redline copy, R. 43-

2). 

Defendants Meng and Med-Zenith moved the district court for a “stay under [§] 3” of the 

FAA so that the claims could be decided in the China Arbitration with AtriCure’s claims against 

ZenoMed. (R. 43, PageID 1173-74, 1178). On October 25, 2019, the district court denied the 

motion, concluding that Meng and Med-Zenith, as nonsignatories to the Distribution Agreement, 

cannot rely on equitable estoppel or agency principles under Ohio law to invoke the arbitration 

provision. (R. 52, PageID 1314-15). Defendants filed this appeal. (R. 53).

II.

With all the facts in hand, a faithful application of the equitable estoppel and agency 

theories under Ohio law permits nonsignatories Meng and Med-Zenith to seek arbitration of 

AtriCure’s claims against them.

A.

The fundamental problem is that the Supreme Court did not jettison pro-arbitration state 

law rules in Arthur Anderson. (Maj. Op. 9-10, 17-18, 20). But that is what this court has done 

today. Arthur Anderson did not announce a novel concept. Long before that decision, the 

Supreme Court said that “[w]hen deciding whether the parties agreed to arbitrate . . ., courts 

generally . . . should apply ordinary state-law principles that govern the formation of contracts.” 

First Options of Chicago, Inc. v. Kaplan, 514 U.S. 938, 944 (1995). This court and the Ohio 

courts understood that principle and recognized that a nonsignatory may invoke or be bound by 

an arbitration clause under various theories, including estoppel and agency. See, e.g., Javitch v. 

First Union Sec., Inc., 315 F.3d 619, 629 (6th Cir. 2003); see also Arnold v. Arnold Corp.–

Printed Commc’ns For Bus., 920 F.2d 1269, 1271, 1281 (6th Cir. 1990); I Sports v. IMG 

Worldwide, Inc., 813 N.E.2d 4, 11 (Ohio Ct. App. 2004); Genaw v. Lieb, No. 20593, 2005 WL 

435211, at *3-4 (Ohio Ct. App. 2005).

Arthur Anderson came about because a panel of this court decided to break rank. 

Rejecting the nonsignatory defendants’ argument that “principles of equitable estoppel 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 27

demanded that [plaintiffs] arbitrate their claims under their investment agreements with [the 

investment company],” this court concluded that § 3 of the FAA is “inapplicable” because “the 

defendants are not signatories to the written agreement in question.” Carlisle v. Curtis, MalletPrevost, Colt & Mosle, LLP, 521 F.3d 597, 598, 600 (6th Cir. 2008). The Supreme Court 

reversed this court’s decision in Arthur Anderson, 556 U.S. at 632. In doing so, the Court made 

it clear that “‘traditional principles’ of state law allow a contract to be enforced by or against 

nonparties to the contract through ‘assumption, piercing the corporate veil, alter ego, 

incorporation by reference, third-party beneficiary theories, waiver and estoppel[.]’” Id. at 631 

(quoting 21 R. Lord, Williston on Contracts § 57:19 (4th ed. 2001)); accord GE Energy Power 

Conversion Fr. SAS, Corp. v. Outokumpu Stainless USA, LLC, 140 S. Ct. 1637, 1643 (2020).

As I see it, the only “federal common-law approach” Arthur Anderson “jettisoned” was 

this court’s use of federal law to restrict arbitration. (Maj. Op. 8-10, 17, 20). Arthur Anderson 

explicitly stated that federal law “cannot possibly require the disregard of state law permitting

arbitration by or against nonparties to the written arbitration agreement.” 556 U.S. at 634 n.5 

(emphasis in original). The Supreme Court’s decision established a shield for state law so long 

as it “permit[s]” arbitration. Id. Indeed, we can invoke federal law to jettison state law rules 

only when: (1) “state law prohibits outright the arbitration of a particular type of claim”; or (2) 

an otherwise “generally applicable” state law rule “stand[s] as an obstacle to the accomplishment 

of the FAA’s objectives.” AT&T Mobility LLC v. Concepcion, 563 U.S. 333, 341-43 (2011). 

Neither situation is implicated by Ohio’s pro-arbitration rules for equitable estoppel and agency. 

The majority even acknowledges that federal law “does not prohibit [states] from singling out 

arbitration for preferential treatment.” (Maj. Op. 23-24). And yet, the majority takes issue with 

perceived differences between Ohio’s “traditional” common law and the Ohio courts’ proarbitration rules for equitable estoppel and agency in the arbitration context. (Maj. Op. 14, 17-

18, 20, 22-23, 24).

Today history repeats itself. Instead of providing a shield, the majority has used Arthur 

Anderson as a sword against Ohio’s pro-arbitration rules.
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 28

B. Equitable Estoppel

Ohio law is clear that two equitable estoppel theories permit nonsignatory defendants 

Meng and Med-Zenith to invoke arbitration under the Distribution Agreement. Equitable 

estoppel is generally applied to “intertwined claims” in two circumstances: (1) “where a 

signatory must rely on the terms of the written agreement in asserting claims against a 

nonsignatory”; and (2) “where the signatory alleges substantially interdependent and concerted 

misconduct by both the nonsignatory and one or more signatories to the contract.” I Sports v. 

IMG Worldwide, Inc., 813 N.E.2d 4, 8 (Ohio Ct. App. 2004) (citing Grigson v. Creative Artists 

Agency, L.L.C., 210 F.3d 524, 527 (5th Cir. 2000), and MS Dealer Serv. Corp. v. Franklin, 

177 F.3d 942, 947 (11th Cir. 1999)). After Arthur Anderson, Ohio courts still apply the two 

theories stated in I Sports. See, e.g., Fries v. Greg G. Wright & Sons, LLC, 120 N.E.3d 426, 444 

(Ohio Ct. App. 2018); Fields v. Herrnstein Chrysler, Inc., No. 12CA827, 2013 WL 772822, at 

*6-7 (Ohio Ct. App. Feb. 7, 2013); Short v. Res. Title Agency, Inc., No. 95839, 2011 WL 

1203906, at *3 (Ohio Ct. App. Mar. 31, 2011).

AtriCure advocates for application of the theories articulated in I Sports. (Appellee Br. 

22-23). And Meng and Med-Zenith advance the same theories by relying on the two federal 

cases I Sports cited. (Appellant Br. 21-22, 26-27, 32; Reply Br. 13). 

1. “Relying On The Contract” Estoppel Theory

The first estoppel theory applies here. Consistent with I Sports, the test the Ohio 

Supreme Court has since applied is whether the plaintiff “asserted claims that arise from the 

contract containing the arbitration clause.” Taylor v. Ernst & Young, L.L.P., 958 N.E.2d 1203, 

1213 (Ohio 2011) (citing Gerig v. Kahn, 769 N.E.2d 381, 386 (Ohio 2002)).1 Taylor concluded 

that the nonsignatory plaintiff’s accounting malpractice claim arose “independently” of the 

contract and was based on allegations identifying “statutory duties and certifications filed in the 

public record.” Id. at 1214, 1215. The court explained that the claim did not “require the court 

1

In Gerig v. Kahn, the court held that “a signatory to a contract may enforce an arbitration provision 

against a nonsignatory seeking a declaration of the signatories’ rights and obligations under the contract.” 

769 N.E.2d at 386. But neither Gerig nor Taylor held (much less suggested) that estoppel is only applicable in that 

situation. (Maj. Op. 14-15). 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 29

to interpret the [agreement] to determine [the accounting firm’s] obligations to [the insurance 

company].” Id. at 1215 (“In no form does the liquidator seek judicial interpretation of the 

[agreement].”). In particular, “the liquidator could trace the alleged harm to [the accounting 

firm] via the public filings and certifications, without reference to the [agreement].” Id. at 1216; 

see also Henderson v. Lawyers Title Ins. Corp., 843 N.E.2d 152, 155 (Ohio 2006) (nonsignatory 

plaintiffs could not arbitrate their claims because they alleged entitlement to a premium credit 

“under the applicable rate schedule filed by [the insurance company],” not under the insurance 

contract).

Taylor did not adopt a rule rejecting equitable estoppel whenever a plaintiff asserts their 

claims under “a statute or tort law.” (Maj. Op. 14). The doctrine extends to a signatory’s 

statutory and tort claims. See Fries, 120 N.E.3d at 444 (concluding that signatory’s tort claims 

for “breach of fiduciary duty, unjust enrichment, and conversion” were subject to arbitration with 

nonsignatory defendants), appeal denied, 114 N.E.3d 1208 (Ohio 2019); see also Fields, 2013 

WL 772822, at *6-7 (concluding that “concerted misconduct” estoppel required arbitration for 

signatory’s claims against nonsignatories for violation of consumer protection statutes and 

common law tort duties).2

Here, in contrast to Taylor, AtriCure cannot make out its claims “without reference” to 

the Distribution Agreement; its claims will inherently require “judicial interpretation” of the 

agreement. Taylor, 958 N.E.2d at 1215-16. In other words, AtriCure “must rely on the terms of 

the [Distribution Agreement] in asserting [its] claims.” I Sports, 813 N.E.2d at 8; see also GE 

Energy Power, 140 S. Ct. at 1644.

For example, AtriCure alleges a claim for tortious interference with a business 

relationship. Under Ohio law, such a claim requires a plaintiff to show: “(1) the existence of a 

contract and/or business relationship; (2) the tortfeasor’s knowledge thereof; (3) the tortfeasor’s 

intentional interference causing a breach or termination of the relationship; (4) lack of 

2Reliance on Church v. Fleishour Homes, Inc., 874 N.E.2d 795 (Ohio Ct. App. 2007), is inapposite. (Maj. 

Op. 14, 17). That case turned on the unique fact that a “child’s cause of action for personal injuries is separate and 

distinct from that of her parents’ claims, [so] it cannot be subject to the parents’ agreement to arbitrate.” Id. at 806-

07.
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 30

justification; and (5) damages.” Harris v. City of St. Clairsville, 330 F. App’x 68, 79 (6th Cir. 

2008) (emphasis added) (citing Fred Siegel Co., L.P.A. v. Arter & Hadden, 707 N.E.2d 853, 858 

(Ohio 1999)). 

Here, AtriCure relies heavily on ZenoMed’s specific contractual breaches caused by 

defendants. “ZenoMed has since breached the Distribution Agreement in numerous 

respects[.]” (R. 1, ¶ 3). “Dr. Meng, the President of ZenoMed, and his colleague Dr. Bai, were 

the primary wrongdoers that directed and caused ZenoMed’s breaches.” (Id., ¶ 4). 

“Defendants, and each of them, acted in concert together and with ZenoMed and Med-Zenith, to 

assist ZenoMed in breaching the Distribution Agreement, assist each other in committing 

fraud and other tortious conduct, and assist Med-Zenith in the theft of AtriCure’s intellectual 

property to develop and sell illegal counterfeit medical devices.” (Id., ¶ 104). The list goes on. 

(Id., ¶¶ 57, 104-05, 110-11). AtriCure even goes so far as to incorporate and recite specific 

provisions of the Distribution Agreement covering confidentiality, non-compete, inventory 

reports, books and records, trademarks, and use of intellectual property, and alleges how 

ZenoMed has breached those provisions. (Id., ¶¶ 24-34, 93, 80).

Moreover, “establishment of the fourth element of the tort of tortious interference with 

contract, lack of justification, requires proof that the defendant’s interference with another’s 

contract was improper.” Fred Siegel, 707 N.E.2d at 858 (emphasis added). Similarly, 

AtriCure’s misappropriation-of-trade-secret claim requires AtriCure to show: “(1) the existence 

of a trade secret; (2) the acquisition of a trade secret as a result of a confidential relationship; and 

(3) the unauthorized use of a trade secret.” Heartland Home Fin., Inc. v. Allied Home Mortg. 

Capital Corp., 258 F. App’x 860, 861 (6th Cir. 2008) (emphasis added) (applying Ohio law). 

Recall that the parties’ arrangement was set up so that “all of the registrations” for doing 

business in China and “all the patents in China” for AtriCure’s products were held under the 

name of one of Meng’s entities or “in his name.” (R. 70, PageID 1563-64). Outside the 

Distribution Agreement, Meng “owned those registrations.” (R. 71, PageID 1641-42). The only 

way AtriCure could do business in China was “through [Meng]’s company, ZenoMed.” (R. 70, 

PageID 1563; R. 1, ¶¶ 4-5). Without the various provisions of the Distribution Agreement, there 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 31

was nothing preventing Meng or his entities from doing as they pleased with AtriCure’s 

technology in China.

How exactly then does AtriCure show “lack of justification” or “unauthorized use” on the 

part of Med-Zenith and Meng (a double-agent), “without reference” to—and ultimately obtaining 

a favorable “judicial interpretation” that ZenoMed breached—the confidentiality, non-compete, 

and nondisclosure provisions of the Distribution Agreement? See Taylor, 958 N.E.2d at 1215-

16; I Sports, 813 N.E.2d at 8. Short of a breach of contract claim between signatories, it is 

difficult to imagine a case where a plaintiff must rely more on the terms of a contract than here. 

Because AtriCure must rely on the terms of the Distribution Agreement to make out its claims, 

Meng and Med-Zenith are entitled to invoke the arbitration clause.

2. “Concerted Misconduct” Estoppel Theory

The second circumstance under which equitable estoppel is applied arises “when the 

signatory to the contract alleges ‘substantially interdependent and concerted misconduct by both 

the non-signatory and one or more of the signatories to the contract.’” I Sports, 813 N.E.2d at 9 

(quoting Hill v. G.E. Power Sys., Inc., 282 F.3d 343, 348 (5th Cir. 2002)). The majority 

concludes that defendants Meng and Med-Zenith forfeited the issue by failing to raise the second 

estoppel theory in the district court. (Maj. Op. 21). Not so.

Meng and Med-Zenith’s reply in support of their motion for an arbitration stay 

recognized that AtriCure’s arguments against equitable estoppel included: (1) that AtriCure 

“does not rely on the 2016 Distribution Agreement in asserting [its] claims”; and (2) AtriCure 

“does not allege interdependent and concerted misconduct by a nonsignatory and signatory to the 

Distribution Agreement.” (R. 51, PageID 1298-99). Meng and Med-Zenith argued:

[T]he plain text of the Complaint contradicts Plaintiff’s assertions. First, 

Plaintiff’s claims rely on the Distribution Agreement because they depend on a 

breach of that contract by ZenoMed. Second, in its Complaint Plaintiff 

specifically alleges significant interdependent and concerted misconduct by 

Defendants and ZenoMed . . .

(R. 51, PageID 1299). Defendants quoted extensively from AtriCure’s complaint to support their 

position and then concluded that “Plaintiff’s claims here rely on allegations that Defendants not 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 32

only caused Plaintiff to enter into the Distribution Agreement with ZenoMed, but also that 

Defendants conspired with and acted in concert with ZenoMed to cause injury to Plaintiff.” 

(Id., PageID 1299-300). “Defendants’ reply brief does nothing more than reply to the allegations 

made in [AtriCure]’s response.” Asbury v. Teodosio, 412 F. App’x 786, 792 (6th Cir. 2011); 

Scottsdale Ins. Co. v. Flowers, 513 F.3d 546, 553 (6th Cir. 2008) (explaining that “reply 

briefs reply to arguments made in the response brief” (internal quotation marks and citation 

omitted)). Meng and Med-Zenith preserved the issue.

Even if that was not the case, once a claim is “properly presented, a party can make any 

argument in support of that claim; parties are not limited to the precise arguments they made 

below.” Citizens United v. FEC, 558 U.S. 310, 330-31 (2010) (emphasis added) (quoting 

Lebron v. Nat’l R.R. Passenger Corp., 513 U.S. 374, 379 (1995)). This court’s cases are not to 

the contrary. (Maj. Op. 21). “Our forfeiture cases ‘recognize a distinction between failing to 

properly raise a claim before the district court and failing to make an argument in support of that 

claim.’” United States v. Reed, 993 F.3d 441, 453 (6th Cir. 2021) (brackets and citations 

omitted). “[W]e typically find no forfeiture on appeal when ‘a particular authority or strain of 

the argument was not raised below, as long as the issue itself was properly raised.’” Id. (citation 

omitted). AtriCure does not argue, and defendants do not concede, that the two estoppel theories 

are “distinct” claims. (Cf. Maj. Op. 22); (Appellee Br. 28-29; Appellant Br. 33-34; Reply Br. 16-

17). That is because defendants’ argument that the second estoppel theory should apply is not a 

new claim. Cf. Citizens United, 558 U.S. at 330-31. Rather, it is an argument that is a 

“subsidiary” or “strain” of the claim raised below—namely, that equitable estoppel allows them 

to invoke arbitration for the claims against them. See Reed, 993 F.3d at 453. And on appeal, 

both parties have fully briefed the second equitable estoppel theory. (Appellant Br. 33-37; 

Appellee Br. 28-31; Reply Br. 16-18). Because Meng and Med-Zenith not only properly 

presented their equitable estoppel claim but also argued the second subsidiary theory, the issue is 

not forfeited.3

3Even assuming arguendo that defendants’ second estoppel theory constitutes a new claim raised for the 

first time on appeal, it satisfies this court’s criteria for consideration. The question— whether the complaint 

“alleges” concerted misconduct between ZenoMed and one or more of the nonsignatory defendants, I Sports, 813 

N.E.2d at 9—“is a purely legal one,” and “the parties have fully briefed the issue,” such that “it is ‘presented with 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 33

The second estoppel theory plainly applies in this case. The complaint is replete with 

allegations of collusion, aiding and abetting, and joint misconduct. (See, e.g., R. 1, ¶¶ 4-5, 39, 

57, 94, 104, 110-11). For instance, the complaint alleges that the “Defendants, and each of 

them, acted in concert together and with ZenoMed and Med-Zenith, to assist ZenoMed in 

breaching the Distribution Agreement, assist each other in committing tortious interference, 

fraud, misappropriation of trade secrets and unfair competition and other tortious conduct.” (R. 

1, ¶ 110). AtriCure’s complaint also expressly alleged a civil conspiracy claim, which, by 

definition, is “a malicious combination of two or more persons to injure another in person or 

property[.]” Kenty v. Transamerica Premium Ins. Co., 650 N.E.2d 863, 866 (Ohio 1995) 

(citation omitted); (e.g., R. 1, ¶¶ 39, 110-11). That alone triggers the second estoppel theory. 

Discovery Res., Inc. v. Ernst & Young U.S. LLP, 62 N.E.3d 714, 720-21 (Ohio Ct. App. 2016)

(holding that signatory’s claims against nonsignatories were subject to arbitration because 

“[t]here can be no question that [plaintiff]’s claim for conspiracy ‘raises allegations of . . . 

concerted misconduct’” (citation omitted)); see also Fields, 2013 WL 772822, at *6-7 (applying 

the rule stated in I Sports and Hill, and concluding that “concerted misconduct” estoppel 

applied); Denney v. BDO Seidman, L.L.P., 412 F.3d 58, 70 (2d Cir. 2005) (“Having alleged in 

[a] RICO action that the Deutsche Bank and BDO defendants acted in concert to defraud 

plaintiffs, . . . plaintiffs cannot now escape the consequences of those allegations[.]”). 

As with some of the defendants in Hill, which I Sports relied upon, “the facts before us 

insofar as [AtriCure]’s claims against nonsignator[ies] [Med-Zenith, Meng, and Bai] are 

inherently inseparable from its claims against [ZenoMed]. [AtriCure]’s complaint makes 

identical claims against both defendants.” Hill, 282 F.3d at 349. In fact, it is telling that the 

China Arbitration demand against ZenoMed is a near carbon-copy of the allegations in this case. 

(R. 43-1; see redline copy, R. 43-2). Under Ohio law, the second estoppel theory applies here.

sufficient clarity and completeness’ to ensure a proper resolution.” United States v. Ellison, 462 F.3d 557, 560 (6th 

Cir. 2006) (quoting Pinney Dock & Transp. Co. v. Penn Cent. Corp., 838 F.2d 1445, 1461 (6th Cir. 1988)). The 

resolution of the issue is also clear here, and “failing to consider the issue would result in a plain miscarriage of 

justice—namely, allowing a conclusion of law to stand that is clearly in error.” Id. at 561 (deciding to consider an 

issue raised for the first time on appeal).
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 34

C. Agency Theory

A remand on the agency theory is not warranted. Under Ohio law, “a nonsignatory agent 

may enforce an arbitration agreement between a plaintiff and the agent’s principal when, as in 

this case, the alleged misconduct arose out of the agency relationship.” Genaw, 2005 WL 

435211, at *4 (emphasis added); Rivera v. Rent A Ctr., Inc., No. 101959, 2015 WL 5455882, at 

*4 (Ohio Ct. App. Sept. 17, 2015); accord Neal v. Navient Sols., LLC, 978 F.3d 572, 575 (8th 

Cir. 2020) (applying Ohio law for agency and estoppel). “[Plaintiffs] will not be allowed to 

circumvent their promise to arbitrate . . . by simply suing [nonsignatory agents] separately from 

[the signatory corporation].” Manos v. Vizar, No. 96 CA 2581-M, 1997 WL 416402, at *1 (Ohio 

Ct. App. July 9, 1997). The majority concedes that this approach “applies here.” (Maj. Op. 22, 

24). 

But the majority’s remand is not supported by Janiga v. Questar Capital Corporation, 

615 F.3d 735 (7th Cir. 2010). There, the district court did not believe there was a “meeting of 

the minds” between the alleged signatories to the agreement, so the district court ended its 

analysis there without addressing whether the nonsignatories could invoke the arbitration 

agreement under an agency theory. Id. at 739. The Seventh Circuit, however, found that there 

was a contract between the signatories, id. at 742-43, but remanded because the district court had 

no “opportunity to pass on [the agency] issues in the first instance,” id. at 743-44. That is not the 

case here.

In this case, the district court cited the rule and considered the agency issue. (R. 52, 

PageID 1313-14 (“[T]he agency exception may be invoked when the relationship between the 

signatory and nonsignatory defendants is sufficiently close that only by permitting the 

nonsignatory to invoke arbitration may evisceration of the underlying arbitration agreement 

between the signatories be avoided.” (quoting I Sports, 813 N.E.2d at 11))). But the district 

court avoided deciding whether Meng was an agent for ZenoMed. Instead, the district court 

stated in conclusory fashion that AtriCure “does not bring its claims against Defendant Meng in 

an attempt to avoid the Agreement’s arbitration provision.” (R. 52, PageID 1313). The court 

erred because the whole point of the agency theory is that “nonsignatory agents should also have 

the benefits of the arbitration agreements made by their principal.” Hussein v. Hafner & 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 35

Shugarman Ents., Inc., No. 09-020, 2010 WL 3481492, at *7 (Ohio Ct. App. Aug. 13, 2010). 

The district court simply misapplied the law to the facts, and that is no reason for a remand. 

Here, Ohio’s agency theory applies to Meng. AtriCure alleges that “Zeno[M]ed has, at 

all times, been chiefly represented by the two Defendants. These Defendants acted together 

and in conspiracy with others to form a competing company and knock-off the AtriCure 

products.” (R. 1, ¶ 24). “To induce AtriCure into the Distribution Agreement with 

ZenoMed, Dr. Meng and Dr. Bai made false representations to, and concealed material facts 

from, AtriCure[.]” (Id., ¶¶ 80, 83-84, 95-96). “As ZenoMed was charged with responsibility for 

licensing in China, and held itself out as having expertise to do so, the officers of ZenoMed, the 

Defendants here, were given access to proprietary and confidential information owned by 

AtriCure.” (Id., ¶ 25). “Dr. Meng and Dr. Bai were fully aware of the Distribution Agreement 

as they are the principals of ZenoMed. They caused ZenoMed to breach the Distribution 

Agreement[.]” (Id., ¶ 57; see also id., ¶¶ 24-25, 31, 37-40, 57). “ZenoMed and its principals, 

Dr. Meng and Dr. Bai, have stolen AtriCure’s intellectual property, which they are now 

marketing for sale around the world.” (Id., ¶ 37; see also id., ¶¶ 4-5, 24-25, 31, 37-40, 57). “Dr. 

Meng, the President of ZenoMed, and his colleague Dr. Bai, were the primary wrongdoers that

directed and caused ZenoMed’s breaches.” (Id., ¶ 4). The testimony of AtriCure’s COO 

reinforces the allegations.4 There is no doubt that AtriCure’s claims arise “out of the agency 

relationship.” Genaw, 2005 WL 435211, at *4.

We should not feign ignorance of these facts to give the district court a second bite at the 

apple. The allegations in the complaint and the other facts in the record are sufficient to 

determine the issue and we need only apply the law. Grand Wireless, Inc. v. Verizon Wireless, 

Inc., 748 F.3d 1, 10 (1st Cir. 2014) (“Grand’s complaint makes clear that Ms. McCahill’s alleged 

actions were taken in her capacity as Verizon’s agent or employee. . . . Grand, in naming Ms. 

4AtriCure’s COO states that Dr. Meng “is the Founder and General Manager of ZenoMed.” (R. 32-1, ¶ 6; 

id., PageID 315). “Dr. Meng and Dr. Bai are the primary representatives of ZenoMed.” (Id., ¶ 5). “Dr. Meng 

was the primary negotiator and contact point on the business relationship between AtriCure and Dr. Meng’s many 

entities, including during the 2014-2016 period in connection with the parties’ negotiation of the Distribution 

Agreement.” (Id., ¶ 35). AtriCure’s COO also states that “[a]s part of the business relationship between AtriCure 

and ZenoMed, ZenoMed, through its officers Dr. Meng and Dr. Bai, was responsible for securing regulatory 

approvals in China for AtriCure’s products.” (Id., ¶ 17). 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 36

McCahill in its complaint, identified her as “Director of Indirect Communication, Erin 

McCahill.”); see also Denney, 412 F.3d at 70 (having alleged “defendants acted in concert,” 

plaintiffs “cannot now escape the consequences of those allegations”). After all, we review the 

denial of an arbitration stay de novo. Albert M. Higley Co. v. N/S Corp., 445 F.3d 861, 863 (6th 

Cir. 2006). Because AtriCure cannot renege on the allegations in its complaint and the testimony 

of its COO, there is no basis for a remand.

D.

The Supreme Court has instructed that “[w]hen [the highest court of the state] has 

spoken, its pronouncement is to be accepted by federal courts as defining state law unless it has 

later given clear and persuasive indication that its pronouncement will be modified, limited or 

restricted.” West v. American Tel. & Tel. Co., 311 U.S. 223, 236 (1940). And “[w]here an 

intermediate appellate state court rests its considered judgment upon the rule of law which it 

announces, that is a datum for ascertaining state law which is not to be disregarded by a federal 

court unless it is convinced by other persuasive data that the highest court of the state would 

decide otherwise.” Id. at 237. A “federal court is not free to apply a different rule however 

desirable it may believe it to be, and even though it may think that the state Supreme Court may 

establish a different rule in some future litigation.” Id. at 238. Moreover, this court has 

repeatedly counseled:

[F]ederal courts sitting in a diversity case are in a particularly poor position to 

endorse [a] fundamental policy innovation . . . . Absent some authoritative signal 

from the legislature of the courts of the state, [there is] no basis for even 

considering the pros and cons of innovative theories.

Combs v. Int’l Ins. Co., 354 F.3d 568, 577-78 (6th Cir. 2004) (cleaned up).

In the majority’s view, Ohio’s estoppel and agency rules in the arbitration context are not 

the same as those in other contexts. But we cannot rewrite state rules simply because we think 

the rules in other contexts are a “better match.” (Maj. Op. 17-18, 20, 22-24). The cases that the 

majority relies on from other contexts are entirely irrelevant here.5

5For example, Doe v. Archdiocese of Cincinnati, 880 N.E.2d 892, 893-94 (Ohio 2008), is not a contract or 

arbitration case. There, the court held that general principles of equitable estoppel did not apply to save plaintiff’s 
No. 19-4067 AtriCure, Inc. v. Meng, et al. Page 37

The majority has not pointed to a “clear and persuasive indication” by the Ohio Supreme 

Court that it would adopt the rules applied or suggested by the majority. As a result, we must 

apply the rules that the Ohio courts apply in the arbitration setting. Application of those rules 

requires reversal.

“Just as judicial antagonism toward arbitration before the Arbitration Act’s enactment 

‘manifested itself in a great variety of devices and formulas declaring arbitration against public 

policy,’ Concepcion teaches that [courts] must be alert to new devices and formulas that would 

achieve much the same result today.” Epic Sys. Corp. v. Lewis, 138 S. Ct. 1612, 1623 (2018) 

(quoting Concepcion, 563 U.S. at 342). Today’s decision is one such example of a “new 

device.”

* * *

For these reasons, I respectfully dissent.

untimely filed complaint for tort claims arising from her sexual relationship with a priest because defendants did not 

do “anything that was designed to prevent [plaintiff] from filing suit.” 880 N.E.2d at 893-95; see also State ex rel. 

Madden v. Windham Exempted Vill. Sch. Dist. Bd. of Educ., 537 N.E.2d 646, 649 (Ohio 1989) (involving asserted 

defenses of “estoppel and laches” to bar a claim). And Hortman v. City of Miamisburg, 852 N.E.2d 716, 718-19 

(Ohio 2006), was not an arbitration case. That case involved claims for “negligence, conversion, and promissory 

estoppel” arising from a city’s “destruction” of trees on plaintiffs’ property, and the court held that “the doctrines of 

equitable estoppel and promissory estoppel are inapplicable against a political subdivision when [it] is engaged in a 

governmental function.” Id. Neither the reasoning nor the holding of a significant number of the cases the majority 

cites has any application here.