Viability assessment with global left ventricular longitudinal strain predicts recovery of left ventricular function after acute myocardial infarction
Background-The extent of viable myocardial tissue is recognized as a major determinant of recovery of left ventricular (LV) function after myocardial infarction. In the current study, the role of global LV strain assessed with novel automated function imaging (AFI) to predict functional recovery after acute infarction was evaluated. Methods and Results-A total of 147 patients (mean age, 61 ±11 years) admitted for acute myocardial infarction were included. All patients underwent 2D echocardiography within 48 hours of admission. Significant relations were observed between baseline AFI global LV strain and peak level of troponin T (r=0.64), peak level of creatine phosphokinase (r=0.62), wall motion score index (r=0.52), and viability index assessed with single-photon emission computed tomography (r=0.79). At 1-year follow-up, LV ejection fraction was reassessed. Patients with absolute improvement in LV ejection fraction ≥5% at 1-year follow-up (n=70; 48%) had a higher (more negative) baseline AFI global LV strain (P<0.0001). Baseline AFI global LV strain was a predictor for change in LV ejection fraction at 1-year follow-up. A cutoff value for baseline AFI global LV strain of-13.7% yielded a sensitivity of 86% and a specificity of 74% to predict LV functional recovery at 1-year follow-up. Conclusions-AFI global LV strain early after acute myocardial infarction reflects myocardial viability and predicts recovery of LV function at 1-year follow-up.