Double factor single shot to diminish complications in cryoballoon ablation procedures for atrial fibrillation

Purpose: Cryoballoon ablation (CBA) has become a standard treatment for recurrent atrial fibrillation (AF). There is need for improved CBA protocols. We aimed to demonstrate that a new protocol including minimum temperature (minT) reached could reduce procedure times and complications. Methods: A new double factor protocol (DFP), based on the performance of one single shot per vein with variable duration, and conditional bonus shot, determined by time-to-effect (TTE) and minT, was compared with the conventional protocol (CP), with at least two shots per vein. Procedure parameters, complications, and efficacy were compared. Results: We prospectively included 88 consecutive patients treated with the DFP. These were compared to the previous consecutive 69 patients treated with CP. All procedures were performed with 28-mm second-generation balloon. Acute pulmonary vein (PV) isolation was similar (98.6% vs. 98.9% in CP vs. DFP, p = 0.687). Procedure and ablation times favored DFP over CP (120 vs. 134 min, p = 0.003; and 1051 vs. 1475 s, p < 0.001; respectively). A composite of major and minor complications was significantly reduced in the DFP compared to the CP (18.8% vs. 6.8%, p = 0.02; respectively). Within a follow-up of 18 months, freedom from AF was 79.7% in CP and 78.4% in DFP (Log-rank 0.501). Paroxysmal AF and absence of PV potentials predicted better arrhythmia outcomes (HR 2.14 for paroxysmal vs. persistent, p = 0.031; and HR 1.61 for absence vs. presence of PV potentials, p = 0.01). Conclusions: The novel DFP results in reduced complication rates and procedure times, with similar success rates compared with a conventional strategy.