Efficacy and safety of additional linear ablation with pulmonary vein isolation for the rhythm control of atrial fibrillation: A meta-anaysis of randomized controlled trials

Many new catheter ablation (CA) methods based on pulmonary vein isolation (PVI) have been developed. The aim of this study was to assess the benefits and harms of additional linear ablation with PVI/ circumferential pulmonary vein ablation (CPVA) in comparison with PVI/CPVA in patients with AF. Ovid-Medline, Ovid-EMBASE, Cochrane library, and seven Korean medical databases were searched to identify studies through May, 2012. To assess the quality of randomized controlled trials (RCTs), the Cochrane risk of bias tool was used. Data were independently extracted by two reviewers using a standardized form. Disagreements between reviewers were resolved by discussion and consensus. The dichotomous data were presented as pooled relative risk (RR) with 95% confidence intervals (CI) using random-effects model. A total of 12 RCTs (1,226 patients) were included and of poor quality. Differences between groups of all-cause mortality were not reported in 12 RCTs. PVI/CPVA plus additional linear ablation, in comparison with PVI/CPVA, increased freedom from atrial tachycardia (AT)/AF (RR 1.10, 95% CI 0.97-1.25, I2=64%) in 12 RCTs, but there was insignificant and moderate heterogeneity among trials. The RR of stroke, transient ischemic attack (TIA) or thrombo-embolic events between both groups was 0.75 (95% CI 0.20-2.81, I2=0%). Fewer complications and adverse events were reported in the trials and there were no differences. The results of meta-analysis showed a trend of favor of PVI/CPVA plus additional linear ablation for freedom from AT/AF, and similar result in the rates of stroke, TIA or thrombo-embolic events. There is limited evidence to suggest that PVI/CPVA plus additional linear ablation may be a better treatment option compared to PVI/CPVA in patients with AF. Well-designed, adequately powered, and long-term clinical trials are warranted.