Cryoballoon versus radiofrequency ablation for persistent atrial fibrillation: a systematic review and meta‑analysis

Clinical outcomes of catheter ablation for persistent atrial fibrillation (AF) remain discouraging. This meta‑analysis aimed to compare cryoballoon ablation (CBA) with radiofrequency ablation (RFA) for persistent AF. A systematic search of the PubMed, EMBASE, and Cochrane Library databases was performed for studies comparing the outcomes between CBA and RFA. Seven trials including 934 patients were analyzed. There were no differences between groups in terms of freedom from atrial arrhythmia (risk ratio [RR], 1.04; 95% CI, 0.93-1.15; P = 0.52; I2 = 0%), procedural complications (RR, 0.91; 95% CI, 0.52-1.59; P = 0.74; I2 = 0%), atrial fibrillation or atrial tachycardia relapse during the blanking period (RR, 0.73; 95% CI, 0.50-1.06; P = 0.1; I2 = 9%), repeat ablation (RR, 0.74; 95% CI, 0.45-1.21; P = 0.23; I2 = 62%), and vascular complications (RR, 0.98; 95% CI, 0.42-2.27; P = 0.97; I2 = 0%). Cryoballoon ablation increased the incidence of conversion to sinus rhythm during ablation (RR, 1.69; 95% CI, 1.01-2.83; P = 0.046; I2 = 0%) and phrenic nerve palsy (PNP; RR, 3.05; 95% CI, 0.95-9.8; P = 0.06; I2 = 0%), while RFA increased the risk of cardiac tamponade (RR, 0.27; 95% CI, 0.06-1.25; P = 0.09; I2 = 0%). Subanalyses revealed a lower incidence of recurrent atrial arrhythmia and repeat ablation during CBA without touch‑up RFA in pulmonary vein isolation. CBA provides an alternative technique for persistent AF ablation. It might reduce the risk of repeat ablation and cardiac tamponade but increase the risk of PNP.