Myocardial Performance Index as a Predictor of IN-Hospital and Short Term Outcome after First Acute Myocardial Infarction

Acute myocardial infarction (MI) remains a leading cause of morbidity and mortality worldwide [1]. It affects both systolic and diastolic functions [2]. In hospital complications of myocardial infarction include arrhythmia, heart failure, post infarction angina and death [2]. Conventional echocardiographic indices that are routinely applied for the estimation of cardiac function face a number of limitations. The ejection fraction, the most reliable estimator of systolic function, is prone to significant inaccuracies when the elliptical cardiac chamber is transformed to a spherical one. On the other hand, transmitral flow, which is the most frequent method for evaluation of diastolic function, is dependent on age, heart rate as well as loading conditions [3]. The Doppler index of combined systolic and diastolic functions (Tei index) was found to be able to separate patients with normal ventricular functions from patients with ventricular dysfunctions [4]. Tei index which is defined as the sum of isovolumetric contraction time and isovolumetric relaxation time divided by ejection time was found to be independent from left ventricular geometry and heart rate. It correlate well with invasive measures of systolic and diastolic left ventricular function [5]. It has been reported to correlate better with patients outcome than conventional echocardiographic parameters in different myocardial diseases [6]. Little information is available about the clinical value of the MPI in patients with acute myocardial infarction. Because morbidity and mortality from AMI was affected by both systolic and diastolic myocardial dysfunction, a parameter that integrates both components might be of particular value in this setting. Tei index was found to be the strongest independent predictor of the development of in-hospital congestive heart failure in a small group of patients with acute myocardial infarction [7]. It has been suggested that in the acute phase of myocardial infarction, the myocardial performance index measured at entry may be useful to predict which patients are at high risk for in hospital cardiac events [8].