Background Cryoballoon (CB) ablation is widely performed for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Anatomic variations in patient pulmonary vein (PV) anatomy are believed to impact short- and long-term procedural success of CB PVI. Methods and Results We hypothesized that failure of initial PV isolation with a standard technique (ie, requiring >2 freeze cycles per PV and/or radiofrequency ablation [RFA] to achieve PV isolation) during index CB PVI procedures would be associated with decreased freedom from AF. We examined a cohort of 177 consecutive patients with drug-refractory AF who underwent CB PVI with a 28-mm balloon second-generation CB device. Mean follow-up time was 19±9 months. Forty-three patients had AF recurrence after the 90-day blanking period after ablation. In 40 patients, acute isolation of one or more PVs could not be achieved by CB ablation with the standard technique (single freeze with or without bonus freeze). To obtain complete acute PVI, 15 patients received extra freeze applications, 20 required supplemental RFA, and 5 received both extra freeze applications and supplemental RFA. Multivariate regression analysis revealed supplemental RFA use during index CB PVI procedures was independently associated with a threefold increased risk of AF recurrence (adjusted hazard ratio, 3.01; 1.45-10.87; P=0.003). Conclusions Use of supplemental RFA during CB PVI procedures to assist with isolation of one or more PVs was independently associated with increased risk of AF recurrence. Use of additional freezes to achieve PVI did not increase the risk for recurrent AF.
Keywords: acute reconnection; atrial fibrillation; cryoballoon; pulmonary vein isolation; supplemental radiofrequency ablation.