Early diastolic strain rate in relation to systolic and diastolic function and prognosis in acute myocardial infarction: a two-dimensional speckle-tracking study

Abstract

Diastolic dysfunction in acute myocardial infarction (MI) is associated with adverse outcome. Recently, the ratio of early mitral inflow velocity (E) to global diastolic strain rate (e'sr) has been proposed as a marker of elevated LV filling pressure. However, the prognostic value of this measure has not been demonstrated in a large-scale setting when existing parameters of diastolic function are known. We hypothesized that the E/e'sr ratio would be independently associated with an adverse outcome in patients with MI. We prospectively included patients with MI and performed echocardiography with comprehensive diastolic evaluation including E/e'sr. The relationship between E/e'sr and the primary composite endpoint (all-cause mortality, hospitalization for heart failure (HF), stroke, and new onset atrial fibrillation) was analysed with Cox models. A total of 1048 patients (mean age 63 ± 12, 73% male) were included and 142 patients (13.5%) reached the primary endpoint (median follow-up 29 months). A significant prognostic value was found for E/e'sr [hazard ratio (HR) per 1 unit change: 2.36, 95% confidence interval (CI): 2.02-2.75, P < 0.0001]. After multivariable adjustment E/e'sr remained independently related to the combined endpoint (HR per 1 unit change, 1.50; CI: 1.05-2.13, P = 0.02). The prognostic value of E/e'sr was driven by mortality (HR per 1 unit change, 2.52; CI: 2.09-3.04, P < 0.0001) and HF admissions (HR per 1 unit change, 2.79; CI: 2.23-3.48, P < 0.0001). Deformation-based E/e'sr contributes important information about global myocardial relaxation superior to velocity-based analysis and is independently associated with the outcome in acute MI.