Sex-specific efficacy and safety of cryoballoon versus radiofrequency ablation for atrial fibrillation: An individual patient data meta-analysis

Background Atrial fibrillation (AF) is a growing health burden, and pulmonary vein isolation (PVI) using cryoballoon (CB) or radiofrequency (RF) represents an attractive therapeutic option. Sex-specific differences in the epidemiology, pathophysiology, and clinical presentation of AF and PVI are recognized. Objective We aimed at comparing the efficacy, safety, and procedural characteristics of CB and RF in women and men undergoing a first PVI procedure. Methods We searched for randomized controlled trials and prospective observational studies comparing CB and RF ablation with at least 1 year of follow-up. After merging individual patient data from 18 data sets, we investigated the sex-specific (procedure failure defined as recurrence of atrial arrhythmia, reablation, and reinitiation of antiarrhythmic medication), safety (periprocedural complications), and procedural characteristics of CB vs RF using Kaplan-Meier and multilevel models. Results From the 18 studies, 4840 men and 1979 women were analyzed. An analysis stratified by sex correcting for several covariates showed a better efficacy of CB in men (hazard ratio for recurrence 0.88; 95% confidence interval 0.78–0.98, P = .02) but not in women (hazard ratio 0.98; 95% confidence interval 0.83–1.16; P = .82). For women and men, the energy source had no influence on the occurrence of at least 1 complication. For both sexes, the procedure time was significantly shorter with CB (−22.5 minutes for women and −27.1 minutes for men). Conclusion CB is associated with less long-term failures in men. A better understanding of AF-causal sex-specific mechanisms and refinements in CB technologies could lead to higher success rates in women.