Cryoballoon ablation was more effective than drug therapy for treating recurrent paroxysmal atrial fibrillation based on the results of the STOP-AF trial. Cryoballoon ablation resulted in 69.9% treatment success compared to 7.3% for drug therapy. Complication rates for cryoballoon ablation were low and within expectations. Pulmonary vein stenosis occurred in a small number of patients but was generally not severe. Phrenic nerve paralysis following cryoballoon ablation was largely reversible.