Valor prognóstico do índice de performance miocárdica no pós-operatório de cirurgia de revascularização miocárdica

Abstract

Myocardial Performance Index (MPI) obtained by Doppler echocardiography for the non-geometrical evaluation of systolic and diastolic function has been described as a method for prognostic evaluation in patients with acute myocardial infarction (AMI). Using the same condition, the objective of this study was to evaluate the predictive value of MPI for cardiovascular complications in patients at low risk during the postoperative period of CABG. Eighty patients submitted to CABG with adequate left ventricular function in the preoperative period were studied, with MPI measured during the first hours postoperatively. Patients were followed until hospital discharge. Statistical analysis included Chi-Square test, Student t test, Mann-Whitney test, and estimation of relative risks with 95% confidence intervals, sensitivity and specificity plus a ROC curve. The data were evaluated by two independent observers blinded to the clinical data with non-significant intra and interobserver variability. MPI=0.43 was found as the cutoff point, considering patients with a higher probability of postoperative events those who had MPI above 0.43. The relevant events for analysis were AMI (RR 0.87 ci 0.21-3.65), atrial fibrillation (RR 0.65 ci 0.24 - 1.76), other arrhythmias (RR 1.51 ci 0.36-6.33), LV dysfunction (RR 1.74 ci 0.32-9.88), with no association between patients with MPI>0.43 and the occurrence of these events. No association was found between MPI and cardiovascular complications and longer hospital stay in this group of patients, and this index was considered not adequate as an isolated predictive method.