Please select the eligibility criteria that correspond to the clinical trial below.
Title: Role of Coumadin in Preventing Periprocedural Thrombo-Embolism as a Complication of Radio Frequency Catheter Ablation in High-risk Atrial Fibrillation Patients
Brief Summary: This study aims to explore the risk of periprocedural thromboembolic events in continuous versus interrupted Coumadin therapy in a large, randomized high-risk patient population undergoing radio-frequency catheter ablation for atrial fibrillation.


Options:
A: Inclusion Criteria:

1. Signed informed consent.
2. \>18 years of age.
3. NVAF with planned catheter ablation treatment.
4. Planned anticoagulant treatment for at least 1 month after the index procedure.
5. Subject agrees to all required follow-up procedures and visits.
6. For women of childbearing potential (WOCBP):

   * Must have a negative serum or urine pregnancy test within 24 hours prior to the start of study drug.
   * Must not be breastfeeding
   * Must agree to follow instructions for method(s) of contraception for a total of 33 days post-treatment completion.
7. Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for a total of 93 days post-treatment completion.
8. Azoospermic males and WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements. However, WOCBP must still undergo pregnancy testing as described in this section.

Exclusion Criteria:

1. History of significant bleeding diathesis or coagulopathy or inability to accept blood transfusions.
2. Known hypersensitivity or contraindication to heparin or apixaban.
3. Subjects with mechanical prosthetic heart valves.
4. History of cerebrovascular accident or transient ischemic attach (TIA) within the last 6 months.
5. Prior intracranial hemorrhage.
6. End-stage renal failure (creatinine clearance rate \<15 mL/minute or on dialysis treatment).
7. Hepatic disease associated with coagulopathy.
8. Current or expected systemic treatment with strong dual inducers of CYP3A4 and P-glycoprotein (e.g., rifampin, carbamazepine, phenytoin, St. John's Wort).
9. Current or expected systemic treatment with dual antiplatelet therapy, other anticoagulants, or fibrinolytics.
10. Planned or expected surgery, or other invasive procedure that would require interruption of anticoagulation within 1 month of the catheter ablation procedure.
11. Currently enrolled in another investigational device or drug trial that has not completed the primary endpoint or that clinically interferes with the current study endpoints.
12. Co-morbid condition(s) that could limit the subject's ability to participate in the trial or to comply with follow-up requirements, or that could impact the scientific integrity of the trial.
13. Platelet count ≤100,000/mm3.
14. Hemoglobin level \<9 g/dL.
15. Any active bleeding.
16. Prisoners or subjects who are involuntarily incarcerated.
17. Subjects who are compulsorily detained for treatment of either a psychiatric or physical (e.g., infectious disease) illness.
B: Inclusion Criteria:

* Age ≥20 or ≤85 years at time of giving informed consent
* Nonvalvular atrial fibrillation
* History of stroke in previous 6 months
* Current or planned treatment with edoxaban
* Modified Rankin scale ≤3

Exclusion Criteria:

* Symptomatic paroxysmal AF resistant to anti-arrhythmic drugs
* Presence of left atrial thrombus and left atrial appendage on transthoracic echocardiography, computed tomography or magnetic resonance imaging
* Unable to take anticoagulation therapy for any reason, including tendency to bleed or considered at high risk for bleeding from anticoagulation therapy.
* Presence of severe renal disorder (estimated creatinine clearance \<30 mL/min by Cockroft-Gault equation)
* Previous CA or surgical intervention for AF
* History of treatment with a left atrial appendage closure device
* Left atrial diameter ≥55 mm on transthoracic echocardiography
* Ejection fraction ≤35% on transthoracic echocardiography
* Persistent AF for ≥10 years
* Pregnant or possibility of pregnancy
* Unlikely to complete the study, such as due to progressive malignant tumor
* Participating or planning to participate in another clinical trial
* Unwilling to participates
* Judged as incompatible for the study by the investigators
C: Inclusion Criteria:

* Atrial Fibrillation, Radiofrequency catheter ablation scheduled

Exclusion Criteria:

* Clinical trial denied
D: Inclusion Criteria:

1. Age- 18-75 years
2. Patients in paroxysmal, persistent or long-standing persistent (LSP) AF
3. patients with CHADS2 score ≥ 1
4. AF patients with INR in the range of 2.0-3.0 in the last 3-4 weeks prior to ablation

Exclusion Criteria:

1. Patients with known bleeding disorders or inherited thrombophilic disorder
2. Patients with oral contraceptives or estrogen replacement therapy
3. Patients with prosthetic heart valves
4. Patients unable or willing to give informed consent
5. Contraindications for Coumadin therapy
6. Patients with CHADS2 score zero
7. Contraindication to undergoing an MRI

Answer: D