Beshai John F, Grimm Richard
University of Chicago Hospital, 5758 South Maryland Avenue, MC 9024, Chicago, Illinois 60637, USA.
J Interv Card Electrophysiol. 2007 Sep;19(3):149-55. doi: 10.1007/s10840-007-9156-3.
Numerous trials have demonstrated the effectiveness of cardiac resynchronization therapy (CRT) as an adjunct to medical therapy for the relief of heart failure (HF) symptoms in patients with a wide QRS duration (QRSd). Current guidelines recommend CRT in patients with an EF <35%, medically refractory NYHA Class III-IV HF and QRSd >or=120 ms. Previous studies have demonstrated QRSd as a marker of electrical dyssynchrony fails to predict response to CRT. In addition, studies have demonstrated significant differences in QRSd post CRT between responders and non-responders. Moreover, smaller non-controlled studies demonstrated that HF patients with a narrow QRSd may benefit from CRT. A growing body of evidence suggests that echocardiographic criteria may be a better method to evaluate mechanical dyssynchrony (MD) which may predict those that will benefit from CRT, particularly those with a narrow QRSd. The Resynchronization Therapy In Narrow QRS (RethinQ) study will evaluate mechanical dyssynchrony using echocardiography (both M mode and TDI) as an eligibility requirement for CRT.
The RethinQ study is a prospective, multi-center, randomized, double blind controlled clinical study. The objective of the RethinQ study is to evaluate the effectiveness of CRT in patients with approved ICD indication, advanced HF (NYHA Classification III), narrow QRSd (<130 ms) and evidence of MD measured by echocardiography.
We hypothesize that patients with narrow QRS <130 ms, advanced HF, and MD as measured by echocardiography will benefit from CRT.
大量试验已证明心脏再同步治疗（CRT）作为药物治疗的辅助手段，可有效缓解宽QRS波时限（QRSd）患者的心力衰竭（HF）症状。当前指南推荐，对于射血分数（EF）<35%、药物治疗效果不佳的纽约心脏协会（NYHA）心功能III-IV级HF且QRSd≥120 ms的患者，应采用CRT治疗。既往研究表明，QRSd作为电不同步的标志物，无法预测CRT的疗效。此外，研究显示，CRT治疗后，有反应者与无反应者的QRSd存在显著差异。而且，规模较小的非对照研究表明，QRSd较窄的HF患者可能从CRT中获益。越来越多的证据表明，超声心动图标准可能是评估机械不同步（MD）的更好方法，MD或许可预测哪些患者将从CRT中获益，尤其是QRSd较窄的患者。窄QRS波再同步治疗（RethinQ）研究将采用超声心动图（M型和组织多普勒成像均用）评估机械不同步，以此作为CRT治疗的入选标准。
RethinQ研究是一项前瞻性、多中心、随机、双盲对照临床研究。RethinQ研究的目的是评估CRT对符合植入式心律转复除颤器（ICD）植入指征、重度HF（NYHA心功能分级III级）、QRSd较窄（<130 ms）且经超声心动图测量有MD证据的患者的疗效。
我们假设，QRSd<130 ms、重度HF且经超声心动图测量有MD的患者将从CRT中获益。
