微循环障碍与急性心肌梗死患者梗死面积、心肌应变及临床预后的相关性分析

目的  分析心脏磁共振评估急性心肌梗死患者微循环障碍（MVO）与梗死面积、心肌应变及临床预后的相关性。方法  选择2022年6~12月蚌埠医学院第一附属医院收治的24例因ST段抬高型心肌梗死（STEMI）行经皮冠状动脉介入治疗术治疗的患者为对象，其中男性22例，女性2例，年龄55.3±11.3岁。所有患者于术后5~7 d进行心脏磁共振检查，根据是否出现MVO，将24例患者分为MVO组（n=16）和非MVO组（n=8），比较两组基线资料、心功能、心肌梗死面积（LGE%）、心肌应变。对出院的STEMI患者进行平均6月的门诊或电话随访，记录心血管不良事件（MACEs）的发生情况，比较两组发生MACEs事件的差异。本研究定义的MACEs事件包括：再发胸痛、心力衰竭、脑卒中、再发心梗、出血、再次血运重建、支架内血栓、支架内再狭窄、死亡。结果  MVO组梗死节段径向应变、梗死节段周向及整体周向应变功能均低于无MVO组（P < 0.05）；MVO组心肌梗死面积大于无MVO组（25.18%±10.51% vs 9.93%±5.96%）。MVO组左心室射血分数与径向应变及周向应变呈极强相关关系[r=0.815 (0.536~0.934)，P < 0.001；r=-0.938(-0.978~-0.852)，P < 0.001]，与纵向应变呈强相关关系[r=-0.767(-0.915~-0.437)，P < 0.001]。
二元回归分析中LGE%及梗死节段周向应变是STEMI患者发生MVO的独立危险因素。单因素分析ROC曲线显示，LGE%可以辅助于MVO的诊断，曲线下面积（AUC）为0.922（0.796~1.000），其最佳截断点为14.92%，敏感度为87.5%，特异性为87.5%（P < 0.05）。梗死节段周向应变对MVO也具有诊断价值，AUC为0.781（0.591~0.971），其最佳截断点为10.58%，敏感度为62.5%，特异性为87.5%（P < 0.05）。LGE%联合梗死节段周向应变后，其对MVO诊断的AUC及敏感度均上升，AUC为0.938（0.827~1.000），敏感度为93.8%，特异性为87.5%（P < 0.05）。随访所有STEMI患者，10例发生MACEs事件（41.7%），两组患者发生MACEs事件的差异无统计学意义（P=0.558）。结论  LGE%、心肌梗死节段周向应变是STEMI患者经皮冠状动脉介入治疗术后出现MVO的独立危险因素，也分别对MVO具有较高的诊断价值，两者联合诊断MVO时诊断价值更高。径向应变、周向应变、纵向应变与MVO组左心室射血分数具有较强的相关性。

Correlation analysis of microcirculation disorders with infarct size,myocardial strain,and clinical prognosis in patients with acute myocardial infarction

Objective To explore the correlation analysis between myocardial MRI assessment of microcirculation disorders (MVO), infarct size, myocardial strain and clinical prognosis in patients with acute myocardial infarction. Methods A total of 24 patients treated with percutaneous coronary intervention for ST segment elevation myocardial infarction (STEMI) at the First Affiliated Hospital of Bengbu Medical College from June 2022 to December 2022 were selected as the study subjects, including 22 male and 2 female patients, with an average age of 55.3±11.3 years old. All patients underwent cardiac magnetic resonance imaging 5-7 d after surgery. Based on the presence and absence of microcirculation disorders, the 24 patients were divided into MVO group (n=16) and non MVO group (n=8), then compared the baseline data, cardiac function, myocardial infarction area (LGE%) and myocardial strain between the two groups. The discharged STEMI patients were followed up for an average of 6 months in the outpatient clinic or by telephone to record the occurrence of adverse cardiovascular events (MACE events), and compare the differences in the MACE events between the two groups. The MACE events defined in this study include recurrent chest pain, heart failure, stroke, recurrent myocardial infarction, bleeding, revascularization, in-stent thrombosis, in-stent restenosis and death. Results The radial strain, circumferential strain, and overall circumferential strain of the infarcted segment in the MVO group were lower than those in the non MVO group (P < 0.05); The myocardial infarction area in the MVO group was larger than that in the non MVO group (25.18%±10.51% vs 9.93%±5.96%). The left ventricular ejection fraction in the MVO group was highly correlated with radial and circumferential strain [r=0.815(0.536-0.934), P < 0.001; r=-0.938(-0.978—-0.852), P < 0.001], and strongly correlated with longitudinal strain [r=-0.767(-0.915—-0.437), P < 0.001]. LGE% and circumferential strain of the infarcted segment in binary regression analysis are independent risk factors for MVO in STEMI patients. In univariate analysis, ROC curve showed that LGE% could assist in the diagnosis of MVO. The AUC was 0.
922 (0.796-1.000), with an optimal cutoff point of 14.92%, sensitivity of 87.5% and specificity of 87.5% (P < 0.05). The circumferential strain of the infarcted segment also has diagnostic value for MVO, with an AUC of 0.781 (0.591- 0.971), an optimal cutoff point of 10.58%, sensitivity of 62.5%, and specificity of 87.5% (P < 0.05). After LGE% was combined with the circumferential strain of the infarcted segment, its AUC and sensitivity for MVO diagnosis increased, with an AUC of 0.938 (0.827-1.000), a sensitivity of 93.8%, and a specificity of 87.5%(P < 0.05). MACE events occurred in a total of 10 STEMI patients followed up in the study, accounting for 41.7% of the total number. There was no statistically significant difference in the occurrence of MACEs events between the two groups of patients (P=0.558). Conclusion LGE% and circumferential strain of myocardial infarction segment are independent risk factors for MVO after percutaneous coronary intervention in STEMI patients, and they also have high diagnostic value for MVO. The combination of the two has higher diagnostic value for MVO. There is a strong correlation between radial strain, circumferential strain, and longitudinal strain and left ventricular ejection fraction in the MVO group.