Cryoballoon pulmonary vein isolation for atrial fibrillation in obese patients: A non-inferiority analysis

BACKGROUND: Patients with obesity are at higher risk of developing atrial fibrillation (AF) and benefit from radiofrequency ablation. Potentially, cryoballoon ablation (CBA) may be equally effective and safe in such patients. METHODS: We conducted a prospective, single-center study to investigate whether CBA for pulmonary vein isolation is as effective and safe in obese patients as it is in non-obese controls. Primary efficacy endpoint was recurrence of AF, atrial flutter or atrial tachycardia after a 90-day blanking period. Safety endpoints were death, stroke or procedure-associated complications. Conduction of a subgroup analysis regarding the impact of additional diabetes was predefined in case the primary efficacy endpoint was met. The study was event driven and powered for noninferiority. RESULTS: A total of 949 patients underwent CBA (251 obese with mean body-mass-index 33.5 ± 3 kg/m(2) and 698 non-obese with mean body-mass-index 25.3 ± 3 kg/m(2)) during a 5-year recruitment period. Median follow-up was 15 months. The primary efficacy endpoint occurred in 78/251 obese and 247/698 non-obese patients (12-months Kaplan-Meier event-rate estimates, hazard ratio 0.79; 95% confidence interval [CI], 0.58 to 1.07; log-rank P = 0.0002 for noninferiority). No differences were observed in safety end point occurrence (P = 0.78). The occurrence of primary efficacy end point was found to be unaffected by the presence of diabetes in the prespecified subgroup analysis (log-rank P = 0.57). CONCLUSION: CBA is effective and safe in obese and DM patients. Weighing the high cardiovascular risk of obese patients against a reduction of cardiovascular events by early rhythm control, CBA should be offered to this patient population.