EJMS

Abstract

Background: Infarct size (IS) determines clinical outcomes following acute myocardial infarction (AMI). Cardiovascular magnetic resonance (CMR) is the sensitive standard test for IS quantification. However, it is expensive and mostly inaccessible, so echocardiographic global longitudinal strain (GLS) has been presented to allow precise measurement of IS. Aim: To evaluate the relation linking echocardiographic GLS with CMR measured IS in patients with early stage AMI with preserved left ventricular ejection fraction (LVEF). Patients and Methods: Forty-seven patients with ST segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention were included in the study. Transthoracic echocardiography and CMR were performed to the patients within 7 days of hospital admission. Measurement of LVEF was performed by modified Simpson’s biplane method. The LVEF was not impaired in the patients with a mean of 45.8%. The two-dimensional speckle tracking was made and curves of longitudinal strain were performed in a 17-segments model, which cover the whole myocardium of left ventricle. An automated GLS measurement was carried out. With the use of late gadolinium enhancement in left ventricular short-axis views, the IS was calculated by CMR. Results: For every 1% increment in IS, GLS worsened by 1.78% (0.64–2.92), P=0.019, after adjusting the results for LVEF, age, and sex. IS was not significantly associated with echocardiographic LVEF: [−0.28 (−0.68-0.12), P=0.571] when adjusted for age and sex. The greatest correlation between GLS and IS was observed at the segmental level in the LV apical segments: worsening by 1.808% (1.220-2.386), P<0.001, for each percent rise in IS. Conclusions: There was a significant correlation between IS and GLS in patients with AMI in its early stage and with preserved LVEF, and the greatest correlation was present at the LV apex. No relation associating the echocardiographic LVEF with IS was observed.