BACKGROUND Benefit from cardiac resynchronization therapy (CRT) varies by QRS characteristics; individual randomized trials are underpowered to assess benefit for relatively small subgroups. METHODS The authors analyzed patient-level data from pivotal CRT trials (MIRACLE [Multicenter InSync Randomized Clinical Evaluation], MIRACLE-ICD [Multicenter InSync ICD Randomized Clinical Evaluation], MIRACLE-ICD II [Multicenter InSync ICD Randomized Clinical Evaluation II], REVERSE [Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction], RAFT [Resynchronization-Defibrillation for Ambulatory Heart Failure], BLOCK-HF [Biventricular Versus Right Ventricular Pacing in Heart Failure Patients with Atrioventricular Block], COMPANION [Comparison of Medical Therapy, Pacing and Defibrillation in Heart Failure], and MADIT-CRT [Multicenter Automatic Defibrillator Implantation Trial - Cardiac Resynchronization Therapy]) using Bayesian Hierarchical Weibull survival regression models to assess CRT benefit by QRS morphology (left bundle branch block [LBBB], n=4549; right bundle branch block [RBBB], n=691; and intraventricular conduction delay [IVCD], n=1024) and duration (with 150-ms partition). The continuous relationship between QRS duration and CRT benefit was also examined within subgroups defined by QRS morphology. The primary end point was time to heart failure hospitalization (HFH) or death; a secondary end point was time to all-cause death. RESULTS Of 6264 patients included, 25% were women, the median age was 66 [interquartile range, 58 to 73] years, and 61% received CRT (with or without an implantable cardioverter defibrillator). CRT was associated with an overall lower risk of HFH or death (hazard ratio [HR], 0.73 [credible interval (CrI), 0.65 to 0.84]), and in subgroups of patients with QRS ≥150 ms and either LBBB (HR, 0.56 [CrI, 0.48 to 0.66]) or IVCD (HR, 0.59 [CrI, 0.39 to 0.89]), but not RBBB (HR 0.97 [CrI, 0.68 to 1.34]; Pinteraction <0.001). No significant association for CRT with HFH or death was observed when QRS was <150 ms (regardless of QRS morphology) or in the presence of RBBB. Similar relationships were observed for all-cause death. CONCLUSIONS CRT is associated with reduced HFH or death in patients with QRS ≥150 ms and LBBB or IVCD, but not for those with RBBB. Aggregating RBBB and IVCD into a single "non-LBBB" category when selecting patients for CRT should be reconsidered. REGISTRATION URL: https://www. CLINICALTRIALS gov; Unique identifiers: NCT00271154, NCT00251251, NCT00267098, and NCT00180271.

中文翻译：

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心脏再同步治疗可改善心室内传导延迟患者的预后，但不能改善右束支传导阻滞：随机对照试验的患者水平荟萃分析。


背景心脏再同步治疗 (CRT) 的益处因 QRS 特征而异；个别随机试验的效力不足以评估相对较小的亚组的益处。方法 作者分析了关键 CRT 试验的患者水平数据（MIRACLE [多中心 InSync 随机临床评估]、MIRACLE-ICD [多中心 InSync ICD 随机临床评估]、MIRACLE-ICD II [多中心 InSync ICD 随机临床评估 II]、REVERSE [再同步可逆转左心室收缩功能障碍的重构]、RAFT [动态心力衰竭的再同步除颤]、BLOCK-HF [伴房室传导阻滞的心力衰竭患者的双心室与右心室起搏]、COMPANION [治疗房室传导阻滞的心力衰竭患者中的​​药物治疗、起搏和除颤的比较心力衰竭] 和 MADIT-CRT [多中心自动除颤器植入试验 - 心脏再同步治疗]）使用贝叶斯分层威布尔生存回归模型通过 QRS 形态评估 CRT 益处（左束支传导阻滞 [LBBB]，n=4549；右束支阻滞 [RBBB]，n=691；心室内传导延迟 [IVCD]，n=1024）和持续时间（150 毫秒分区）。还在 QRS 形态定义的亚组中检查了 QRS 时限和 CRT 益处之间的连续关系。主要终点是心力衰竭住院（HFH）或死亡的时间；次要终点是全因死亡的时间。结果 在 6264 名患者中，25% 为女性，中位年龄为 66 [四分位距，58 至 73] 岁，61% 接受了 CRT（带或不带植入式心脏复律除颤器）。 CRT 与整体较低的 HFH 或死亡风险相关（风险比 [HR]，0.73 [可信区间 (CrI)，0.65 至 0）。84]），以及 QRS ≥ 150 ms 且 LBBB（HR，0.56 [CrI，0.48 至 0.66]）或 IVCD（HR，0.59 [CrI，0.39 至 0.89]）但不是 RBBB（HR 0.97）的患者亚组[CrI，0.68 至 1.34]；P 相互作用 <0.001）。当 QRS <150 ms（无论 QRS 形态如何）或存在 RBBB 时，未观察到 CRT 与 HFH 或死亡显着相关。全因死亡也观察到类似的关系。结论 对于 QRS ≥ 150 ms、LBBB 或 IVCD 患者，CRT 与减少 HFH 或死亡相关，但与 RBBB 患者无关。在选择 CRT 患者时，应重新考虑将 RBBB 和 IVCD 合并为一个“非 LBBB”类别。注册网址：https://www.临床试验政府；唯一标识符：NCT00271154、NCT00251251、NCT00267098 和 NCT00180271。