The association between myocardial early systolic lengthening and high risk angiographic territory involvement in patients with non-ST-segment elevation myocardial infarction.

Abstract

Non-ST-segment elevation myocardial infarction (NSTEMI) is more common than ST-segment elevation myocardial infarction (STEMI), consisting of 60-70% of myocardial infarctions. When left ventricular (LV) pressure increases during early systole, regionally ischaemic myocardium with a reduced active force exhibit stretching. The aim of this study was to evaluate the role of this parameter in determining high risk angiographic territory involvement in NSTEMI patients. This study was a descriptive correlational research that was conducted on 96 patients with NSTEMI and a left ventricular ejection fraction ≥ 50% who underwent coronary angiography (CAG). Patients were divided into two groups based on having or not having high risk angiographic territory involvement in CAG. All patients underwent a transthoracic echocardiography during the first day of hospitalization and early systolic lengthening (ESL), duration of ESL (DESL), left ventricular global longitudinal strain (LVGLS), pulsed-wave Doppler-derived transmitral early (E wave) and late (A wave) diastolic velocities, and tissue-Doppler-derived mitral annular early diastolic (e') and peak systolic (s') velocities were determined. The results of this study showed DESL, DESLLAD, and DESLLCX were longer in high risk angiographic territory group than other one (P value 0.016, 0.044, and 0.04, respectively). The logistic regression analysis showed among different variables, only age and ESLLAD had an independent association with high risk angiographic territory involvement (P = 0.01, odds ratio [OR] 1.09, 95% CI 1.021-1.164, and P = 0.024, odds ratio [OR] 1.243, 95% CI 1.029-1.50, respectively). Assessment of myocardial ESLLAD by speckle-tracking echocardiography may be helpful in predicting high risk angiographic territory involvement in patients with NSTEMI. Indeed, a higher value can be considered as a high risk parameter which may show benefit of an early invasive strategy versus a conservative approach.