Left Atrial Stiffness: A Predictor of Atrial Fibrillation Recurrence after Radiofrequency Catheter Ablation - A Systematic Review and Meta-Analysis

Abstract Background: Radiofrequency catheter ablation (RFCA) is a standard procedure for patients with atrial fibrillation (AF) not responsive to previous treatments, that has been increasingly considered as a first-line therapy. In this context, perioperative screening for risk factors has become important. A previous study showed that a high left atrial (LA) pressure is associated with AF recurrence after ablation, which may be secondary to a stiff left atrium. Objective: To investigate, through a systematic review and meta-analysis, if LA stiffness could be a predictor of AF recurrence after RFCA, and to discuss its clinical use. Methods: The meta-analysis followed the MOOSE recommendations. The search was performed in MEDLINE and Cochrane Central Register of Controlled Trials databases, until March 2018. Two authors performed screening, data extraction and quality assessment of the studies. Results: All studies were graded with good quality. A funnel plot was constructed, which did not show any publication bias. Four prospective observational studies were included in the systematic review and 3 of them in the meta-analysis. Statistical significance was defined at p value < 0.05. LA stiffness was a strong independent predictor of AF recurrence after RFCA (HR = 3.55, 95% CI 1.75-4.73, p = 0.0002). Conclusion: A non-invasive assessment of LA stiffness prior to ablation can be used as a potential screening factor to select or to closely follow patients with higher risks of AF recurrence and development of the stiff LA syndrome.

背景：射频导管消融术（Radiofrequency catheter ablation, RFCA）是既往治疗无效的心房颤动（atrial fibrillation, AF）患者的标准术式，如今其作为一线治疗方案的认可度与日俱增。在此背景下，围手术期危险因素筛查的重要性愈发凸显。既往研究表明，左心房（left atrial, LA）压力升高与消融术后心房颤动复发相关，该关联可能继发于左心房僵硬状态。
目的：本研究通过系统评价与荟萃分析，探讨左心房僵硬度是否可作为射频导管消融术后心房颤动复发的预测因子，并讨论其临床应用价值。
方法：本荟萃分析遵循MOOSE报告规范开展。检索时限截至2018年3月，检索数据库涵盖MEDLINE及Cochrane对照试验中心注册库。由两名研究者独立完成文献筛选、数据提取及研究质量评估。
结果：所有纳入研究均被评定为高质量。所绘制的漏斗图未显示存在发表偏倚。系统评价共纳入4项前瞻性观察性研究，其中3项被纳入本次荟萃分析。本研究设定统计学显著性阈值为p<0.05。分析结果显示，左心房僵硬度是射频导管消融术后心房颤动复发的强独立预测因子（风险比（Hazard Ratio, HR）=3.55，95%置信区间（Confidence Interval, CI）1.75~4.73，p=0.0002）。
结论：消融术前无创评估左心房僵硬度，可作为潜在的筛查指标，用于筛选术后心房颤动复发及左心房僵硬综合征发病风险更高的患者，或对该类患者实施密切随访。