Single 3-minute freeze for second-generation cryoballoon ablation: one-year follow-up after pulmonary vein isolation

Abstract

Background: The second-generation cryoballoon (CB-Adv) is effective in achieving pulmonary vein isolation (PVI) with encouraging results. The mid-term clinical efficacy of a single 3-minute freeze, without a routine bonus application, has been recently demonstrated.

Objective: The purpose of this study was to assess long-term clinical outcome after PVI with the CB-Adv using a single 3-minute application.

Methods: A total of 143 consecutive patients (93 male [65%], mean age 59.6 ± 12.0 years) with paroxysmal atrial fibrillation (PAF; 113/143 [79%]) or early persistent atrial fibrillation (AF; 30/143 [21%]) underwent PVI using CB-Adv with a single 3-minute freeze. Atrial tachyarrhythmia recurrences were defined as symptomatic or documented episodes >30 seconds.

Results: After a single freeze, isolation could be reached in 94.1% of all identified pulmonary veins. Complete PVI was successfully achieved with 1.1 ± 0.4 mean freezes. Persistent phrenic nerve palsy occurred in 5 of 143 patients (3.5%). At a mean 12.1 ± 4.4 months of follow-up, after a 3-month blanking period (BP), 80.4% (115/143) were in stable sinus rhythm (93/113 [82.3%] for PAF; 22/30 [73.3%] for early persistent AF). Fifteen patients underwent a second procedure with radiofrequency ablation showing reconnection in 7 of 15 right-sided (46.7%) and 6 of 15 left-sided (40%) pulmonary veins. Relapses during BP (P <.01), time to PVI (P = .02), and longer AF duration (P = .04) were independent predictors of recurrences.

Conclusion: A single 3-minute freeze is highly effective, determining an atrial tachyarrhythmia freedom of 80.4% at 1-year follow-up. The incidence of persistent phrenic nerve palsy is 3.5%. Relapses during BP, time to PVI, and longer AF duration are predictors of recurrences. Routine use of an "insurance freeze" may not be needed.

Keywords: 1-year follow-up; 3-minute freeze; Atrial fibrillation; Cryoballoon ablation; Pulmonary vein isolation; Second-generation cryoballoon; Single freeze.