[Layer-specific strain assessment on left ventricular function before and after PCI in patients with ST segment
1Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang 212001, China.
Abstract:
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.
