In a late-breaking session at the 2019 European Heart Rhythm Association annual congress (EHRA; 17–19 March, Lisbon, Portugal), Jason Guy Andrade of Vancouver, Canada presented results of the CIRCA-DOSE study, a randomised clinical trial designed to evaluate the safety and efficacy of second-generation cryoablation versus contact-force irrigated radiofrequency catheter ablation for atrial fibrillation, as well as double short (2-minute) versus standard (4-minute) cryoapplication exposure.
Andrade presented the conclusion that pulmonary vein isolation performed by advanced generation cryoballoon or by contact-force guided radiofrequncy results in comparable freedom from recurrent atrial arrhythmia.
In addition, he noted the “stark contrast” between the primary endpoint, defined as time to first event, and the reduction in atrial fibrillation burden, which “highlights the need to reappraise the optimal atrial fibrillation ablation study endpoint.” His final conclusion was that efficacy is not compromised by using a shorter cryoablation duration.
Freedom from any atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) after a single ablation procedure revealed comparable event-free survival rates between CF-RF (53.9%), CRYO-4 (52.2%) and CRYO-2 (51.7%).
A similar trend was apparent in freedom from symptomatic tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) after a single procedure, with an event-free survival rate of 79.1% in both the CF-RF and CRYO-4 groups, and 73.3% in the CRYO-2 group.
Andrade detailed that the trial was conducted in eight centres across Canada and enrolled 353 patients in total.
