Prognostic value of multiparametric cardiac magnetic resonance after revascularized STEMI

Abstract Despite early revascularization of STEMI through angioplasty, the prognosis following STEMI remains poor for a non-negligible percentage of patients (1). In this setting, multiple imaging parameters have demonstrated their prognostic value. The aim of the present study is to evaluate which of these parameters are the most potent predictors of events following revascularized STEMI. Methods A prospective observational study was conducted, including a cohort of revascularized STEMI patients and who underwent cardiac MRI during the first week. The protocol included cardiac functional analysis and with b-SSFP sequences for evaluation of volumes, mass, ejection fraction and also circumferential and radial strain with feature tracking. STIR sequences were used to assess edema and salvaged myocardium, IR-FGE sequences were employed for evaluation of necrosis size and microvascular obstruction. Intra-infarct hemorrhage assessment was performed using T2* mapping sequences as previosly described (2,3,4) . A semi-automatic analysis was conducted, considering as microvascular obstruction segments with hypointensity in the infarct core and as segments with hemorrhage those with a T2* less than 20 ms. The association of imaging parameters with cardiovascular events in the first year following STEMI was studied using ROC curves. Variables with significant association were analyzed using a multivariate logistic regression model. Results Ninety-four patients with a mean age of 63 (SD 13) years were included. Nine of them had cardiovascular events in the first year and two of them died. The relative extent of necrosis and microvascular obstruction, minimal radial strain, left ventricular ejection fraction (LVEF) and indexed left ventricular end- systolic volume (ILVESV) showed significant association with cardiovascular events after STEMI. Variables with significant association were entered into a multivariate predictive model, revealing that the extent of microvascular obstruction (OR: 1.9, p=0.02) and the left ventricular end-systolic volume (OR: 1.04, p<0.01) are the only independent predictors of cardiovascular events following STEMI. Conclusion Although multiple imaging parameters have shown prognostic value after STEMI, the ILVESV and the extent of microvascular obstruction are the only independent predictors of events following STEMI.Multiparametric cardiac MR in STEMIAREA UNDER ROC CURVE OF CMR PARAMETERS