A prospective, multicenter trial of irrigated radiofrequency ablation and cryoablation to treat nonparoxysmal atrial fibrillation

Abstract

Background: Concomitant surgical ablation of atrial fibrillation (AF) improves AF-free survival, decreases stroke risk, and improves quality of life (QOL). This clinical trial evaluated the efficacy and safety of irrigated radiofrequency (iRF) ablation and cryoablation for the treatment of nonparoxysmal AF (NPAF). Methods: In this prospective, multicenter study, a Cox-Maze IV lesion set using iRF and cryoablation was performed to treat NPAF in patients undergoing concomitant cardiac surgery. Pulmonary vein isolation (PVI) was assessed intraoperatively. The primary efficacy endpoint was freedom from atrial tachyarrhythmias (ATAs; ie, AF/atrial flutter/atrial tachycardia) of ≥30 seconds after a 90-day washout from antiarrhythmic drugs (AADs) through 12 months. The primary safety endpoint was the rate of major adverse events (MAEs) at 30 days/discharge. MAEs and rhythm assessments were adjudicated independently. Results: Among the 94 treated patients, the mean age was 69 ± 7 years, and 61 (65%) were male. Fifty-one patients (54%) had persistent AF, and 43 (46%) had long-standing persistent AF. PVI was confirmed in 100% of patients tested (65 of 65). Freedom from ATAs through 12 months was 76.2% (64 of 84; 95% Bayesian credible interval [BCI], 66.0%-84.0%). Using the Kaplan-Meier method, freedom from ATAs and AADs at 12 months was 80% (95% CI, 70%-87%). Seven of 93 patients (7.5%; 95% BCI, 3.7%-14.7%) had 10 MAEs through 30 days. The ≤30-day mortality rate was 4.3% (95% BCI, 1.7%-10.5%). QOL scores at 12 months (n = 81) improved significantly from baseline (P < .001). Conclusions: This trial showed a high rate of success at restoring sinus rhythm with a low complication rate and improved QOL when treating NPAF with iRF clamps and cryoablation. These excellent results support wider adoption of concomitant AF ablation.