All patients underwent pulmonary vein isolation (and eventually left atrial posterior wall isolation) with the POLARx™ cryoballoon system

Primary effectiveness failure is defined as the composite of any of the following occurrences:

Failure to achieve acute procedural success at the index procedure (pulmonary vein isolation); More than one repeat procedure during the blanking period (within 90 days post-index procedure); Documented atrial fibrillation, or new onset of atrial flutter or atrial tachycardia event (≥ 30 seconds in duration or from a 10 second 12-lead ECG) Repeat procedure for atrial fibrillation, or new onset of atrial flutter or atrial tachycardia Electrical and/or pharmacological cardioversion

• Prescribed a new antiarrhythmic drug not documented at baseline Prescribed a higher dose of antiarrhythmic drug documented at baseline

Safety is defined as the composite of any of the following occurrences:

Death Myocardial infarction Persistent gastroparesis/injury to vagus nerve Stroke/Transient ischemic attack Thromboembolism/ Air embolism Cardiac tamponade/perforation Pneumothorax Serious vascular access complications* Pulmonary edema/Heart Failure Ablation related atrioventricular block not attributable to medication effect or vasovagal reaction.

Safety events (0-30 days post procedure) Symptomatic pericardial effusion Safety events (0-360 days post procedure) Atrial esophageal fistula Persistent Phrenic nerve injury Pulmonary Vein Stenosis

* Including hematoma requiring intervention or prolongation of hospital stay, artero-venous fistulas or pseudoaneurysm.