Mascioli Giosuè, Padeletti Luigi, Sassone Biagio, Zecchin Massimo, Lucca Elena, Sacchi Stefania, Boggian Giulio, Tondo Anna Ludovica, Belvito Chiara, Bakhtadze Nikoloz, Borrelli Alessio, Sinagra Gianfranco
Department of Arrhythmology, Cliniche Humanitas Gavazzeni, Bergamo, Italy.
Pacing Clin Electrophysiol. 2012 Aug;35(8):927-34. doi: 10.1111/j.1540-8159.2012.03427.x. Epub 2012 May 31.
Cardiac resynchronization therapy (CRT) has proved to be very effective in improving morbidity and mortality in patients affected with severe congestive heart failure. Its efficacy has been shown to be greater in patients with left bundle branch block (LBBB). The aim of our study was to verify if newly proposed criteria for true LBBB identify patients with a better clinical and instrumental response to CRT.
Between May 2007 and April 2011, 111 patients with left ventricular ejection fraction (LVEF) ≤ 35% and LBBB morphology received a CRT device and were divided into two groups according to QRS morphology. Group 1 (61 patients) consisted of patients with "true" LBBB morphology; group 2 (50 patients) consisted of patients with "false" LBBB. The primary endpoint was the utility of criteria for true LBBB to predict a composite endpoint of all-cause mortality and hospital admission with heart failure. The secondary endpoint was the utility of the same criteria to predict an absolute increase in LVEF ≥ 10%.
"False" LBBB morphology and a dose of bisoprolol <5 mg at last follow-up were the only parameters related to clinical outcome in multivariate analysis (respectively: hazard ratio [HR] 3.98, confidence interval [CI] 95% 1.51-10.48; HR 0.15, CI 95% 0.05-0.43). "True" LBBB morphology was the only variable significantly related to a greater increase in LVEF (HR 4.57, CI 95% 1.36-8.28).
True LBBB morphology is related to a higher event-free survival rate in CRT patients and better echocardiographic response.
心脏再同步治疗（CRT）已被证明在改善重度充血性心力衰竭患者的发病率和死亡率方面非常有效。在左束支传导阻滞（LBBB）患者中，其疗效更为显著。我们研究的目的是验证新提出的真正LBBB的标准是否能识别出对CRT有更好临床和器械反应的患者。
在2007年5月至2011年4月期间，111例左心室射血分数（LVEF）≤35%且具有LBBB形态的患者接受了CRT装置，并根据QRS形态分为两组。第1组（61例患者）为具有“真正”LBBB形态的患者；第2组（50例患者）为具有“假性”LBBB的患者。主要终点是真正LBBB的标准预测全因死亡率和因心力衰竭住院的复合终点的效用。次要终点是相同标准预测LVEF绝对增加≥10%的效用。
在多变量分析中，“假性”LBBB形态和最后一次随访时比索洛尔剂量<5mg是与临床结局相关的唯一参数（分别为：风险比[HR]3.98，95%置信区间[CI]1.51 - 10.48；HR 0.15，95%CI 0.05 - 0.43）。“真正”LBBB形态是与LVEF更大增加显著相关的唯一变量（HR 4.57，95%CI 1.36 - 8.28）。
真正的LBBB形态与CRT患者更高的无事件生存率和更好的超声心动图反应相关。
