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

Background: 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.

Methods: 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.

Results: 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%).

Conclusions: 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.