分层应变评价急性ST段抬高型心肌梗死患者PCI前后左心功能

Layer-specific strain assessment on left ventricular function before and after PCI in patients with ST segment elevation myocardial infarction

目的利用分层应变技术评价急性ST段抬高型心肌梗死(STEMI)患者接受经皮冠状动脉介入治疗(PCI)前及治疗后24 h内左心室心肌功能的变化,探索连续、定量评价患者心肌功能的新方法。方法本研究为前瞻性队列研究。选取2017年7月至2018年7月因急性前壁STEMI于江苏大学附属医院行急诊PCI的患者40例为研究对象。根据症状至球囊扩张时间(STB)分为STB≤6 h组(26例)及6 h<STB<12 h组(14例)。分别在PCI术前、术后即刻、术后3 h、术后24 h行超声心动图检查。获取左心室各节段心内膜下心肌纵向应变(LS-endo)、全层心肌纵向应变(LS)及左心室整体纵向应变(GLS)。计算梗死区域各节段平均LS-endo值(记为IALS-endo)及平均LS值(记为IALS);非梗死区域各节段平均LS-endo值(记为NIALS-endo)及平均LS值(记为NIALS)。结果本研究共纳入40例急性前壁STEMI患者,其中男性34例,女性6例,年龄(62±10)岁。STB≤6 h组患者,术后24 h的IALS-endo值[(13.7±4.9)%比(10.0±2.7)%,P<0.05]及NIALS-endo值[(17.0±2.9)%比(14.6±2.9)%,P<0.05]均高于术前。6 h<STB<12 h组患者,术后即刻IALS-endo值较术前下降[(6.7±3.3)%比(11.9±6.5)%,P<0.05],术后3 h时呈回升趋势,但与术后即刻比较差异无统计学差异(P>0.05),术后24 h时该指标较术后即刻升高[(13.6±8.4)%比(6.7±3.3)%,P<0.05];术后24 h的NIALS-endo值高于术前[(17.1±2.1)%比(14.5±3.2)%,P<0.05]。6 h<STB<12 h组中术后即刻IALS-endo下降比例高于STB≤6 h组[93%(13/14)比35%(9/26),P<0.001]。6 h<STB<12 h组的术后24 h NIALS值高于术前(P<0.05),其余各时点的IALS、NIALS及GLS差异无统计学意义(P均>0.05)。结论分层LS对STEMI患者左心室心肌功能评估优于全层LS及GLS。超声心动图测得的LS可连续、定量评价STEMI患者PCI前后左心室心肌功能的变化。

Objective To evaluate the changes of left ventricular function in patients with ST segment elevation myocardial infarction(STEMI)before PCI and within 24 hours after PCI by layer-specific strain,and to explore the value of this new assessment method for quantitative monitoring on the myocardial function in STEMI patients.Methods A total of 40 patients with acute anterior wall myocardial infarction,who underwent PCI in Affiliated Hospital of Jiangsu University during July 2017 to July 2018,were included in this prospective cohort study.According to the symptom to balloon time(STB),the patients were divided into STB≤6 hours group(26 cases)and STB 6-12 hours group(14 cases).Echocardiography was performed before,immediately,3 hours and 24 hours after PCI.Echocardiographic indexes including endocardial myocardial longitudinal strain(LS-endo),18-segment full-thickness myocardial longitudinal strain(LS)of left ventricle and left ventricular global longitudinal strain(GLS)were measured.The mean LS-endo and LS values of myocardial segments in infarcted area(IALS-endo,IALS)and the mean LS-endo and LS values of myocardial segments in non-infarcted area(NIALS-endo,NIALS)were calculated.Results There were 34 males and 6 females in this cohort and age was(62±10)years.In STB≤6 hours group,the IALS-endo value((13.7±4.9)%vs.(10.0±2.7)%,P<0.05)and NIALS-endo value((17.0±2.9)%vs.(14.6±2.9)%,P<0.05)were significantly higher at 24 hours after PCI than those before PCI.In the group of STB 6-12 hours,IALS-endo decreased immediately after PCI((6.7±3.3)%vs.(11.9±6.5)%,P<0.05),and there was a rising trend at 3 hours after PCI(P>0.05).At 24 hours after PCI,the index was higher than that immediately after PCI((13.6±8.4)%vs.(6.7±3.3)%,P<0.05).The NIALS-endo value was significantly higher at 24 hours after PCI than that before PCI((17.1±2.1)%vs.(14.5±3.2)%,P<0.05).In the STB 6-12 hours group,the decrease rate of IALS-endo immediately after PCI was higher than that in the STB≤6 hours group(93%(13/14)vs.35%(9/26),P<0.001).In STB≤6 hours group,the NIALS value at 24 hours after PCI was higher than that before PCI(P<0.05),and there was no significant difference in IALS,NIALS and GLS at other time points(P>0.05).Conclusions Layered LS is superior to full-thickness LS and GLS in evaluating left ventricular function in STEMI patients.LS measured by echocardiography can continuously and quantitatively evaluate the changes of left ventricular myocardial function in STEMI patients before and after PCI.