Extent of Left Atrial Ablation Lesions and Atrial Fibrillation Recurrence after Catheter Ablation - A Systematic Review and Meta-Analysis

Abstract Background: Atrial fibrillation (AF) is known to induce atrial remodeling, which promotes fibrosis related to arrhythmogenesis. Accordingly, since scars induced by catheter ablation (CA) can reduce unablated fibrotic areas, greater extent of left atrial (LA) scarring may be associated with less AF recurrence after CA. Objectives: This study aims to investigate, through systematic review and meta-analysis, whether the amount of LA scarring, seen on late gadolinium enhancement magnetic resonance imaging, is associated with less AF recurrence after CA. Methods: The recommendations of the MOOSE guideline were followed. Database search was conducted in PubMed and Cochrane Central Register of Controlled Trials (comentário 1) until January 2019 (comentário 2). Two authors performed screening, data extraction, and quality evaluation. All studies were graded as good quality. A funnel plot was generated, showing no publication bias. Statistical significance was defined as p value < 0.05. Results: Eight observational studies were included in the systematic review, four of which were included in the meta-analysis. Six of the eight studies included in the systematic review showed that greater extension of LA scarring is associated with less AF recurrence after CA. Meta-analysis showed that greater extension of LA scarring is associated with less AF recurrence (SMD = 0.52; 95% CI 0.27 - 0.76; p < 0.0001). Conclusion: Greater extension of LA scarring is possibly associated with less AF recurrence after CA. Randomized studies that explore ablation methods based on this association are fundamental.

摘要 背景：已知心房颤动（Atrial Fibrillation, AF）可诱发心房重构，进而促进与致心律失常作用相关的纤维化形成。据此，导管消融（Catheter Ablation, CA）所形成的瘢痕可减少未消融的纤维化区域，因此左心房（Left Atrial, LA）瘢痕负荷更大可能与导管消融术后房颤复发率更低相关。
研究目的：本研究拟通过系统评价与荟萃分析，探讨左心房钆延迟增强磁共振成像（late gadolinium enhancement magnetic resonance imaging）所示的瘢痕负荷是否与导管消融术后房颤复发率降低相关。
研究方法：本研究遵循MOOSE指南开展。于PubMed及考克兰对照试验中心注册库（Cochrane Central Register of Controlled Trials）（注释1）检索截至2019年1月（注释2）的相关文献。由两名研究者独立完成文献筛选、数据提取与质量评价，所有纳入研究均被评为高质量。生成漏斗图显示无发表偏倚。统计学显著性阈值设定为P<0.05。
研究结果：共8项观察性研究纳入系统评价，其中4项被纳入荟萃分析。纳入系统评价的8项研究中，6项结果显示左心房瘢痕负荷更大与导管消融术后房颤复发率更低显著相关。荟萃分析结果表明，左心房瘢痕负荷更大与房颤复发率降低相关（标准化均数差（Standardized Mean Difference, SMD）=0.52；95%置信区间（Confidence Interval, CI）：0.27~0.76；P<0.0001）。
研究结论：左心房瘢痕负荷更大可能与导管消融术后房颤复发率降低相关。基于此关联开展消融方法相关的随机对照研究至关重要。