Acute Procedural Success was defined as a demonstration of electrical isolation in ≥ 3 Pulmonary Veins (PVs) at the conclusion of the first protocol-defined cryoablation procedure. APS was decided at the end of the procedure the mean time was calculated for the time frame.

Subjects that did not have or were free of CTF. CTF was defined as the occurence of an Atrial Fibrillation (AF) intervention, use of non-study AF drug therapy, or the occurence of detectable AF which is is defined as an episode of AF, documented in a tracing, and lasting more than 30 seconds, occurring during a Non Blanked Follow-up Period.

Treatment Success was defined as Acute Procedure Success (APS) and freedom from Chronic Treatment Failure (CTF) for Experimental Subjects, and freedom from CTF for Control Subjects. Under this pre-specified definition of Treatment Success, Experimental Subjects must have had APS and remained free of CTF during the 12-month follow-up duration, while Control Subjects must have remained free of CTF during the 12-month follow-up duration.

Subjects that did not have or were free of MAFEs. MAFEs were serious adverse events categorized as cardiovascular death, myocardial infarction, stroke, or hospitalization for AF recurrence/ablation, flutter ablation, embolic events, heart failure, hemorrhage or anti-arrhythmic drug treatment.

Subjects that had CPEs. CPEs were device- or procedure-related serious adverse events (SAE) categorized as access site complications, cardiac damage, pulmonary vein (PV) stenosis, embolic complications, arrhythmias, unresolved phrenic nerve palsy and death.