Muto Carmine, Gasparini Maurizio, Iacopino Saverio, Peraldo Carlo, Curnis Antonio, Sassone Biagio, Diotallevi Paolo, Davinelli Mario, Valsecchi Sergio, Tuccillo Bernardino
Ospedale Santa Maria di Loreto Mare, Napoli, Italy.
Am Heart J. 2008 Oct;156(4):656-61. doi: 10.1016/j.ahj.2008.06.011. Epub 2008 Aug 27.
Although cardiac resynchronization therapy (CRT) has a well-demonstrated therapeutic effect in selected patients with advanced heart failure on optimized drug therapy, nonresponder rate remains high. The LODO-CRT is designed to improve patient selection for CRT. Design and rationale of this study are presented herein.
LODO-CRT is a multicenter prospective study, started in late 2006, that enrolls patients with conventional indications for CRT (symptomatic stable New York Heart Association class III-IV on optimized drug therapy, QRS > or =120 milliseconds, left ventricular [LV] dilatation, LV ejection fraction < or =35%). This study is designed to assess the predictive value of LV contractile reserve (LVCR), determined through dobutamine stress echocardiography (defined as an LV ejection fraction increase >5 units), in predicting CRT response during follow-up. Assessment of CRT effects will follow 2 sequential phases: in phase 1, CRT response end point is defined as LV end-systolic volume reduction > or =10% at 6 months; in phase 2, both LV end-systolic volume reduction and clinical status via a clinical composite score will be evaluated at 12 months follow-up. Predictive value of LVCR will be compared to other measures, such as LV dyssynchrony measures, through adjusted multivariable analysis. For the purpose of the study, target patient number is 270 (with 95% confidence, 80% power, alpha < or = .05). Enrollment should be complete by the end of 2008.
The LODO-CRT trial is testing the hypothesis that LVCR assessment, using low-dose dobutamine stress echocardiography test, should effectively predict positive response to CRT both in terms of the reverse remodeling process as well as favorable long-term clinical outcome. Moreover, the predictive value of LVCR will be compared to that of conventional intra-LV dyssynchrony measures.
尽管心脏再同步治疗（CRT）在经过优化药物治疗的特定晚期心力衰竭患者中已显示出明确的治疗效果，但无反应率仍然很高。LODO-CRT旨在改善CRT的患者选择。本文介绍了该研究的设计和原理。
LODO-CRT是一项多中心前瞻性研究，于2006年末启动，纳入有CRT常规适应证的患者（在优化药物治疗下，纽约心脏协会心功能分级为有症状的稳定Ⅲ-Ⅳ级，QRS≥120毫秒，左心室[LV]扩张，左心室射血分数≤35%）。本研究旨在评估通过多巴酚丁胺负荷超声心动图确定的左心室收缩储备（LVCR，定义为左心室射血分数增加>5个单位）在预测随访期间CRT反应方面的预测价值。对CRT效果的评估将分两个连续阶段进行：在第1阶段，CRT反应终点定义为6个月时左心室收缩末期容积减少≥10%；在第2阶段，将在12个月随访时评估左心室收缩末期容积减少情况以及通过临床综合评分评估的临床状态。将通过调整后的多变量分析将LVCR的预测价值与其他指标（如左心室不同步指标）进行比较。为了该研究的目的，目标患者数量为270例（95%置信区间，80%检验效能，α≤0.05）。入组应在2008年底完成。
LODO-CRT试验正在检验这样一个假设，即使用低剂量多巴酚丁胺负荷超声心动图检测评估LVCR，在逆向重构过程以及良好的长期临床结局方面，均应能有效预测对CRT的阳性反应。此外，将把LVCR的预测价值与传统的左心室内不同步指标的预测价值进行比较。
