AIMS Cardiac resynchronization therapy (CRT) restores mechanical efficiency to the failing left ventricular (LV) by resynchronization of contraction. Global, LV myocardial work efficiency (GLVMWE) can be quantified non-invasively with echocardiography. The prognostic implication of GLVMWE remains unexplored, and we therefore related GLVMWE before CRT to long-term prognosis. METHODS AND RESULTS Data were analysed from an ongoing registry of patients with Class I indications for CRT. GLVMWE was defined as the ratio of constructive work in all LV segments, divided by the sum of constructive and wasted work in all LV segments, as a percentage. It was derived from speckle tracking strain echocardiography and non-invasive blood pressure measurements, taken pre-CRT. Patients were dichotomized according to baseline, median GLVMWE [75%; interquartile range (IQR) 66-81%]. A total of 153 patients (66 ± 10 years, 72% male, 48% ischaemic heart disease) were analysed. After a median follow-up of 57 months (IQR 28-76 months), 31% of patients died. CRT recipients with less efficient baseline energetics (GLVMWE <75%) demonstrated lower event rates than patients with more efficient baseline energetics (GLVMWE ≥75%) (log-rank test, P = 0.029). On multivariable analysis, global LV wasted work ratio <75% pre-CRT was independently associated with a decreased risk of all-cause mortality (hazard ratio 0.48, 95% confidence interval 0.25-0.92; P = 0.027), suggesting that the potential for improvement in LV efficiency is important for CRT benefit. CONCLUSION GLVMWE can be derived non-invasively from speckle tracking strain echocardiography and non-invasive blood pressure recordings. A lower GLVMWE before CRT is independently associated with improved long-term outcome.

中文翻译：

---

心脏再同步治疗前总体左心室心肌工作效率的预后意义。

AIMS心脏再同步治疗（CRT）通过收缩再同步来恢复衰竭左心室（LV）的机械效率。超声心动图可以无创地量化整体LV心肌工作效率（GLVMWE）。GLVMWE的预后意义尚待探讨，因此我们将CRT之前的GLVMWE与长期预后相关联。方法和结果从正在进行的I类CRT适应症患者的登记中分析数据。GLVMWE定义为所有LV段中的建设性工作的比率除以所有LV段中的建设性工作和浪费的工作之和的百分比。它源自在CRT前进行的斑点跟踪应变超声心动图和无创血压测量。根据基线，中位GLVMWE [75％；四分位间距（IQR）66-81％]。总共分析了153例患者（66±10岁，男性72％，缺血性心脏病48％）。在中位随访57个月（IQR 28-76个月）后，有31％的患者死亡。基线能量效率较低（GLVMWE <75％）的CRT接受者的事件发生率低于基线能量效率较高（GLVMWE≥75％）的患者（对数秩检验，P = 0.029）。在多变量分析中，CRT前总体LV浪费工作率<75％与降低全因死亡率的风险独立相关（危险比0.48，95％置信区间0.25-0.92； P = 0.027），表明潜在的潜在风险。 LV效率的提高对于CRT的益处很重要。结论GLVMWE可以通过散斑跟踪应变超声心动图和无创血压记录无创地获得。