Prognostic value of combined myocardial performance index in patients with acute ST-elevation myocardial infarction

Abstract

Abstract Background Myocardial performance index (MPI) also known as Tei index is a unique echocardiographic parameter which can estimate both systolic and diastolic performances of left and right ventricles. We previously suggested the echocardiographic parameter combined MPI (CMPI) as a new predictor of the prognosis of acute ST-elevation myocardial infarction (STEMI). The CMPI is the sum of left ventricular (LV) MPI and right ventricular (RV) MPI (CMPI = LV MPI + RV MPI). We supposed that CMPI might be a better predictor in STEMI, because it reflects both ventricular systolic and diastolic functions. Objectives The purpose of this study is to assess the prognostic value of a new echocardiographic parameter CMPI in STEMI patients calculated in acute phase. Methods 240 STEMI patients who underwent primary PCI have been included in the study. Echocardiography (EchoCG) was performed, and LV MPI and RV MPI were assessed within 24 hours after the symptom onset, prior to primary PCI. The MPI was calculated as the sum of isovolumic contraction time (ICT) and isovolumic relaxation time (IRT), divided by the ejection time (ET): MPI = (ICT + IRP) / ET. 50 % of the patients had anterior STEMI. 30 patients (12.5%) had concomitant RV myocardial infarction (MI). Patients were divided into two groups: Group 1 – CMPI > 0.9 (110 patients), Group 2 – CMPI ≤ 0.9 (130 patients). Baseline demographic and clinical characteristics were similar in both groups. Also, there were no differences in LV MI localization and concomitant RV MI between the groups. Primary endpoints were in-hospital and the one-year cardiovascular mortality rates. The secondary endpoint was the one-year heart failure hospitalization rate. Results In Group 1 the in-hospital mortality rate was 9.1%, and 3.1% in Group 2 (p = 0.0489). One-year cardiovascular mortality rate was 12.7% in and 5.4%, respectively (p = 0.0465). One-year heart failure hospitalization was also significantly lower in Group 2 (22.7% vs. 12.3%, p = 0.0332). Conclusion CMPI can be offered as a new predictor for the in-hospital and one-year cardiovascular mortality and one-year heart failure hospitalization rate in patients with acute STEMI.