Verification of a Novel Atrial Fibrillation Cryoablation Dosing Algorithm Guided by Time-to-Pulmonary Vein Isolation: Results from the Cryo-DOSING Study (Cryoballoon-ablation DOSING Based on the Assessment of Time-to-Effect and Pulmonary Vein Isolation Guidance)

Abstract Background There are no recommendations on the optimal dosing for cryoablation of atrial fibrillation (Cryo-AF). Objective We developed and prospectively tested a Cryo-AF dosing protocol guided exclusively by time-to-pulmonary vein (PV) isolation (TT-PVI) in patients undergoing a first-time Cryo-AF. Methods In this multicenter study, we examined the acute/long-term safety/efficacy of Cryo-AF using the proposed dosing algorithm (Cryo-AFDosing , n=355) against a conventional, non-standardized approach (Cryo-AFConventional , n=400) in a non-randomized fashion. Results Acute PV isolation was achieved in 98.9% of patients in Cryo-AFDosing (TT-PVI=48±16 sec) vs. 97.2% in Cryo-AFConventional (P=0.18). Cryo-AFDosing was associated with shorter (149±34 vs. 226±46 sec; P