One-Year Clinical Outcome of Pulmonary Vein Isolation Using the Second-Generation Cryoballoon: A Meta-Analysis

The second-generation cryoballoon (CB-2G) is a promising technique to treat atrial fibrillation (AF). It is necessary to summarize and analyze the available data on 1-year clinical outcome of pulmonary vein isolation (PVI) with CB-2G.

PubMed and the Web of Science were searched in May 2015. Studies that reported the 1-year clinical success rates after PVI using CB-2G were included. The 1-year clinical success rates were pooled using the random-effect model. Complication rates and acute success rates were also analyzed. Subgroup analyses were conducted based on AF type and ablation strategy.

Fifteen studies involving 2,363 AF patients met the inclusion criteria. The overall clinical success rate of PVI using CB-2G was 81%. A total of 82% of paroxysmal AF patients and 70% of persistent AF patients were in stable sinus rhythm 1 year after the procedure. The clinical success rates of the "no-bonus" strategy were 81% in all patients, 82% in paroxysmal AF patients, and 73% in persistent AF patients. The corresponding success rates of the "bonus" strategy were 81%, 83%, and 63%. Acute success rate was high. The overall rates of phrenic nerve palsy (PNP) and other procedure-related complications were 5.8% and 1.5%, respectively. Compared with "bonus" strategy, there was a trend of fewer PNPs in "no-bonus" strategy (4.6% vs 6.5%).

CB-2G is highly effective in the treatment of both paroxysmal AF and persistent AF. The "no-bonus" strategy is as effective as the "bonus" strategy in terms of 1-year clinical outcome.