HFpEF and Symptomatic Obstructive Iliofemoral Venous Disease Study

To ascertain the potential symptom improvement assessed by Cardiopulmonary Exercise Testing (CPET) in subjects with heart failure with preserved ejection fraction (HFpEF) and nonthrombotic iliofemoral venous lesions and/or iliocaval obstruction defined by MR or CT venography AND CEAP Clinical Category ≥3 prior to venous stenting.

Primary Objective:

Evaluate potential improvement in metrics of functional capacity assessed by Cardiopulmonary Exercise Testing performed before and after venous stenting of an ≥50% iliofemoral venous obstruction by MR or CT venography and confirmed by intra-procedural IVUS in a prospective patient cohort presenting with heart failure with preserved ejection fraction with a H2FpEF score of ≥4 AND a CEAP Category ≥3.

Secondary Objectives:

Identify patient demographic, baseline laboratory, imaging, procedural and Cardiopulmonary Exercise Testing variables and the FDA-approved Minnesota Living with Heart Failure Questionnaire as a Medical Device Development Tool (MDDT) in patients with and without functional improvement as assessed by Cardiopulmonary Exercise Testing VO2max after successful venous stenting of iliofemoral/iliocaval venous obstructions.

Eligibility Criteria:
Inclusion Criteria:

* Willing and able to provide informed consent and comply with all study requirements
* Age ≥ 40 years of age
* Stable, symptomatic heart failure with preserved ejection fraction and a H2FpEF Score ≥4
* Presence of non-malignant inferior vena cava obstruction, a unilateral or bilateral chronic non-malignant obstruction of the common femoral vein, external iliac vein, common iliac vein, or any combination thereof, defined as a ≥50% reduction in target vessel lumen diameter defined by screening MRV, CTV and confirmed by a 50% reduction in luminal area as assessed by intraprocedural IVUS.
* Previous (\>6 months) history of ilio-femoral and/or lower extremity deep venous thrombosis associated with a residual ilio-femoral venous obstruction ≥50% by MRV, CTV.
* Clinically significant venous obstruction meeting CEAP Clinical classification ≥3.
* Negative pregnancy test in females of child-bearing potential

Exclusion Criteria:

* Subject hospitalized for acute compensated heart failure within 60 days prior to enrollment
* Presence of history of clinically significant pulmonary emboli within 6 months prior to enrollment.
* Subject has any permanent neurologic defect that may cause non-compliance with the protocol
* Subject has known life-limiting immunosuppressive or autoimmune disease (e.g., human immunodeficiency virus, systemic lupus erythematous).
* Subject has an allergy to contrast media that cannot be adequately pre-treated prior to the required diagnostic and/or endovascular procedures.
* Subject has an active peptic ulcer or active gastrointestinal (GI) bleeding.
* Subject has renal failure or chronic kidney disease with glomerular filtration rate (GFR) ≤ 30 mL/min or Modification of Diet in Renal Disease (MDRD) study equation result of ≤ 30 mL/min per 1.73 m2.
* Subject has white blood cell (WBC) count \< 3.0 (3000 cells/mm3) within 7 days prior to index procedure.
* Subject has a platelet count \< 80,000 cells/mm3 or \> 700,000 cells/mm3 ≤ 7 days pre procedure; uncorrected hemoglobin of ≤9 g/dL.
* Subject has known or suspected active systemic infection evidenced by WBC \> 14.0 (14,000/mm3).
* Subject is currently participating in another investigational drug or device study.
* Subject intends to participate in another investigational drug or device study within 30 days after the index procedure.
* Subject has moderate or severe pulmonary disease (i.e., COPD) considered by Investigator to be a major contributing factor to the subject's exertional dyspnea