The Baker Heart & Diabetes Institute, Clinical Electrophysiology Research, Melbourne, Australia; The Heart Centre, The Alfred Hospital, Melbourne, Australia; Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia.
The Baker Heart & Diabetes Institute, Clinical Electrophysiology Research, Melbourne, Australia; The Heart Centre, The Alfred Hospital, Melbourne, Australia; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia.
J Am Coll Cardiol. 2017 Oct 17;70(16):1949-1961. doi: 10.1016/j.jacc.2017.08.041. Epub 2017 Aug 27.
Atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) frequently co-exist despite adequate rate control. Existing randomized studies of AF and LVSD of varying etiologies have reported modest benefits with a rhythm control strategy.
The goal of this study was to determine whether catheter ablation (CA) for AF could improve LVSD compared with medical rate control (MRC) where the etiology of the LVSD was unexplained, apart from the presence of AF.
This multicenter, randomized clinical trial enrolled patients with persistent AF and idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%). After optimization of rate control, patients underwent cardiac magnetic resonance (CMR) to assess LVEF and late gadolinium enhancement, indicative of ventricular fibrosis, before randomization to either CA or ongoing MRC. CA included pulmonary vein isolation and posterior wall isolation. AF burden post-CA was assessed by using an implanted loop recorder, and adequacy of MRC was assessed by using serial Holter monitoring. The primary endpoint was change in LVEF on repeat CMR at 6 months.
A total of 301 patients were screened; 68 patients were enrolled between November 2013 and October 2016 and randomized with 33 in each arm (accounting for 2 dropouts). The average AF burden post-CA was 1.6 ± 5.0% at 6 months. In the intention-to-treat analysis, absolute LVEF improved by 18 ± 13% in the CA group compared with 4.4 ± 13% in the MRC group (p < 0.0001) and normalized (LVEF ≥50%) in 58% versus 9% (p = 0.0002). In those undergoing CA, the absence of late gadolinium enhancement predicted greater improvements in absolute LVEF (10.7%; p = 0.0069) and normalization at 6 months (73% vs. 29%; p = 0.0093).
AF is an underappreciated reversible cause of LVSD in this population despite adequate rate control. The restoration of sinus rhythm with CA results in significant improvements in ventricular function, particularly in the absence of ventricular fibrosis on CMR. This outcome challenges the current treatment paradigm that rate control is the appropriate strategy in patients with AF and LVSD. (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction [CAMERA-MRI]; ACTRN12613000880741).
尽管进行了充分的心率控制，心房颤动（AF）和左心室收缩功能障碍（LVSD）仍经常同时存在。现有的针对不同病因的 AF 和 LVSD 的随机研究报告称，节律控制策略具有适度益处。
本研究的目的是确定对于 AF 进行导管消融（CA）是否可以改善 LVSD，而 LVSD 的病因除了 AF 之外，尚无法解释。
这项多中心、随机临床试验纳入了持续性 AF 和特发性心肌病（左心室射血分数[LVEF]≤45%）患者。在优化心率控制后，患者接受心脏磁共振（CMR）检查以评估 LVEF 和晚期钆增强，这表明存在心室纤维化，然后再随机分配至 CA 或持续的药物心率控制（MRC）。CA 包括肺静脉隔离和后侧壁隔离。通过植入式环路记录器评估 CA 后的 AF 负荷，通过连续 Holter 监测评估 MRC 的充分性。主要终点是 6 个月时重复 CMR 检查的 LVEF 变化。
共筛选了 301 例患者；2013 年 11 月至 2016 年 10 月期间纳入了 68 例患者并进行了随机分组，每组 33 例（考虑到 2 例脱落）。CA 后 6 个月时的平均 AF 负荷为 1.6±5.0%。意向治疗分析显示，CA 组的 LVEF 绝对改善 18±13%，而 MRC 组仅为 4.4±13%（p<0.0001），并且 58%的患者恢复正常（LVEF≥50%），而 MRC 组仅为 9%（p=0.0002）。在接受 CA 的患者中，晚期钆增强的缺失预测 LVEF 的绝对改善更大（10.7%；p=0.0069），6 个月时的正常化（73% vs. 29%；p=0.0093）。
尽管进行了充分的心率控制，AF 仍然是该人群中 LVSD 的一个被低估的可逆病因。CA 恢复窦性心律可显著改善心室功能，特别是在 CMR 上无心室纤维化的情况下。这一结果挑战了目前的治疗模式，即对于 AF 和 LVSD 患者，心率控制是适当的策略。（心房颤动伴收缩功能障碍的导管消融与药物心率控制[CAMERA-MRI]；ACTRN12613000880741）。
