Echocardiographic longitudinal strain identifies myocardial viability and predicts left ventricular function and remodeling after acute myocardial infarction with systolic dysfunction

Abstract

The routine use of CMR is limited after acute MI. To assess whether echocardiographic strain could (1) identify myocardial viability in comparison with late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR), (2) predict global left ventricular (LV) functional recovery and remodeling and (3) assess prognosis after acute MI with LV systolic dysfunction. TTE and LGE CMR were performed in 71 patients between 2 and 45 days after first STEMI with LVEF ≤ 45% treated with acute PCI. Segments were defined as viable when transmural LGE extension was < 50% and non viable when it was ≥ 50%. At 8-month follow-up, echocardiography was repeated to determine global LV functional recovery (increase in LVEF ≥ 5%) and LV remodeling (increase in end-systolic volume > 15%) ( n = 30) and clinical outcomes ( n = 49) were obtained. Global longitudinal strain (GLS) was lower in non viable than in viable infarct segments (−6.6 ± 6.1% vs. −10.3 ± 5.9%, P < 0.0001) and in viable infarct segments than in normal segments (−10.3 ± 5.9% vs. −14.5 ± 6.4%, P < 0.0001). GLS > −12% had sensitivity of 78% and specificity of 69% to identify non-viable segments (area under the curve (AUC), 0.79; 95% confidence interval (CI), 0.77–0.81, P < 0.0001). GLS > −11.3% had sensitivity of 53% and specificity of 100% to predict the absence of global functional improvement (AUC = 0.73 (CI: 0.55–0.87) P = 0.01) at 8-month follow-up. GLS < −12.5% predicted the absence of adverse LV remodeling at 8-month follow-up with a sensitivity of 100% and a specificity of 54% (AUC = 0.83 (CI: 0.66–0.94) P < 0.0001). GLS > −11.5% was associated with a poor prognosis. In patients with recent first acute MI with LV systolic dysfunction, echocardiographic GLS (1) is able to identify non viable segments in comparison with LGE CMR, (2) allows prediction of LV global functional recovery and LV remodeling at 8-month follow-up and (3) provides strong prognostic information, independently of LVEF.