Comparison of the First and Second Cryoballoon

BACKGROUND: Cryoballoon (CB) ablation results in >70% freedom from atrial fibrillation at 1 year. Single-center data of the first (CBG1) and second (CBG2) cryoballoon, recently introduced, were analyzed to compare safety and efficacy. METHODS AND RESULTS: From March 2011 to December 2012, CB ablation with spiral mapping was performed consecutively in 484 patients with symptomatic atrial fibrillation. CBG1 was used in 364 of 484 (75%) and CBG2 in 120 of 484 (25%) patients. Periprocedural data were analyzed. Acute pulmonary vein (PV) isolation with CB only was achieved in 99.86% and 100% of veins with CBG1 and CBG2, respectively (P=0.43). Number of applications until PV isolation decreased significantly with CBG2 (1.45±0.81 versus 1.28±0.64; P=0.001). Procedural, left atrial, and fluoroscopy time were reduced by -5%, -11%, and -15% (P<0.05), respectively. Two balloons were used less frequently. Time to isolation decreased significantly with 23-mm (48 versus 33 seconds; P<0.0001) and 28-mm CBG2 (76 versus 52 seconds; P<0.0001). Early PV reconduction rarely occurred with CBG2 (2.6% versus 0.42%; P=0.0023). In-hospital atrial fibrillation recurrence rates were similar. Balloon temperatures were significantly warmer with 23-mm CBG2 and a trend for colder balloon temperature with 28-mm CBG2 were observed compared with their predecessors. Comparable low rates of phrenic nerve palsy were recorded (1.1% versus 1.7%; P=0.64). Esophageal temperatures were similar. Major complication rates were low (3.3% versus 3.33%; P=1.0). CONCLUSIONS: CBG2 attains high rates of acute PV isolation within a significant faster and less complex procedure. Time to isolation is shorter, and PV isolation is achieved with fewer applications using CBG2. These enhancements were not at the cost of complications. Long-term success rates remain to be demonstrated.