Using Cryoballoon Ablation as Initial Treatment for Persistent Atrial Fibrillation

This study is to assess the effectiveness and safety of using cryoballoon ablation comparing with anti-arrhythmic drug therapy as initial treatment for naive patients with persistent atrial fibrillation.

Subjects with persistent atrial fibrillation with no history of treatment with anti-arrhythmic drugs are randomized 1:1 to either an anti-arrhythmic drug or pulmonary vein isolation using the cryoballoon catheter.

Eligibility Criteria:
Inclusion Criteria:

* Documentation of symptomatic persistent AF: Defined as having a continuous episode lasting longer than 7 days but less than 1 year documented by consecutive ECG recordings OR Defined as having a continuous episode lasting longer than 7 days but less than 1 year documented by an ECG recording and one doctor note indicating patient had symptoms consistent with AF
* Age 18 -75 years old
* Structurally normal heart with LVEF ≥50%, interventricular septum thickness ≤ 12 mm, and left atrial diameter \<46 mm (short axis) as obtained by transthoracic echocardiography. •
* Normal ECG parameters when measured in sinus rhythm (QRS width ≤120 ms in a 12-channel surface ECG, QTc interval \<440 ms, and PQ interval ≤210 ms).

Exclusion Criteria:

* History of AF treatment with class I or III antiarrhythmic drug, including sotalol, with the intention to prevent an AF recurrence. However, patients pretreated with above AAD for less than 7 days with the intention to convert an AF episode are allowed.
* left atrial ablation or surgical procedure (including left atrial appendage closures)
* Presence or likely implant of a permanent pacemaker, biventricular pacemaker, loop recorder, or any type of implantable cardiac defibrillator (with or without biventricular pacing function) within 12 months
* Presence of any pulmonary vein stents
* Presence of any pre-existing pulmonary vein stenosis
* Pre-existing hemidiaphragmatic paralysis
* Presence of any cardiac valve prosthesis
* +3 and +4 mitral valve regurgitation or stenosis
* Any cardiac surgery, myocardial infarction, percutaneous coronary intervention (PCI) / percutaneous transluminal coronary angioplasty (PTCA) or coronary artery stenting which occurred during the 3 month interval preceding e consent date
* Unstable angina
* New York Heart Association (NYHA) Class II, III or IV congestive heart failure
* Primary pulmonary hypertension
* Rheumatic heart disease
* Thrombocytosis, thrombocytopenia
* Any condition contraindicating chronic anticoagulation
* Active systemic infection
* Hypertrophic cardiomyopathy
* Cryoglobulinemia
* Uncontrolled hyperthyroidism
* Any cerebral ischemic event (strokes or transient ischemic attacks (TIAs)) which occurred during the 6 month interval preceding the consent date
* Any woman known to be pregnant or breastfeeding.
* Life expectancy less than one year
* Current or anticipated participation in any other clinical trial of a drug, device or biologic during the duration of the study not pre-approved by Medtronic
* Active intracardiac thrombus
* Known drug or alcohol dependency
* Unwilling or unable to comply fully with study procedures and follow-up
* Significant Chronic Kidney Disease-estimated Glomerular Filtration Rate(CKD-eGFR) \<30umol/L