Background:Assessment of left ventricular (LV) function in patients with secondary mitral regurgitation (SMR) remains challenging but is an important parameter for risk stratification. The association of LV myocardial work components (work index [GWI], constructive [GCW] and wasted [GWW] work, and work efficiency) derived from pressure-strain loops obtained with speckle tracking echocardiography, and all-cause mortality in patients with SMR was investigated.Methods:LV myocardial GWI, GCW, GWW, and global work efficiency were measured with speckle tracking strain echocardiography in 373 patients (72% men, median age 68 years) with various grades of SMR. All-cause mortality was the primary end point.Results:Mild SMR was observed in 143 patients, 128 had moderate SMR, and 102 had severe SMR. Patients with severe SMR had the largest LV volumes and the worst LV ejection fraction and LV global longitudinal strain. In patients with severe SMR, LV GWI and GCW were more impaired (500 mm Hg% versus 680 mm Hg% P=0.024 and 678 mm Hg% versus 851 mm Hg% P=0.006, respectively), while GWW was lower (130 mm Hg% versus 260 mm Hg% P<0.001, respectively) and global work efficiency was significantly higher (82% versus 76%, P=0.001) compared with patients with mild SMR. After a median follow-up of 56 months, 161 patients died. LV GWI≤500 mm Hg%, LV GCW≤750 mm Hg%, and LV GWW<300 mm Hg% were independently associated with excess mortality.Conclusions:Patients with severe SMR had the worst LV GWI and LV GCW but better LV GWW and global work efficiency reflecting the unloading of the LV in the low-pressure left atrial chamber. These parameters were independently associated with worse long-term survival in patients with SMR.

中文翻译：

---

继发性二尖瓣关闭不全患者左心室心肌工作指数的预后意义

背景：继发性二尖瓣关闭不全 (SMR) 患者的左心室 (LV) 功能评估仍然具有挑战性，但它是风险分层的重要参数。LV 心肌工作成分（工作指数 [GWI]、建设性 [GCW] 和浪费的 [GWW] 工作以及工作效率）与 SMR 患者的压力应变环的关联方法：采用斑点追踪应变超声心动图对 373 名不同级别 SMR 患者（72% 男性，中位年龄 68 岁）测量左室心肌 GWI、GCW、GWW 和整体工作效率。全因死亡率是主要终点。结果：143例患者观察到轻度SMR，128例为中度SMR，102例为重度SMR。严重 SMR 患者的 LV 容积最大，LV 射血分数和 LV 整体纵向应变最差。在重度 SMR 患者中，LV GWI 和 GCW 受损更严重（500 mm Hg% vs 680 mm Hg%P = 0.024 和 678 mm Hg% 与 851 mm Hg% P =0.006），而 GWW 较低（分别为 130 mm Hg% 和 260 mm Hg% P <0.001），整体工作效率显着更高（82%） 76%，P = 0.001）与轻度 SMR 患者相比。中位随访 56 个月后，161 名患者死亡。LV GWI≤500 mm Hg%、LV GCW≤750 mm Hg%和LV GWW<300 mm Hg%与超额死亡率独立相关。结论：重度SMR患者的LV GWI和LV GCW最差，但LV GWW和反映低压左心房中 LV 卸载的整体工作效率。这些参数与 SMR 患者较差的长期生存率独立相关。