Early predictors of left ventricular function improvement late after myocardial infarction

Background/Aim. Prognosis after acute myocardial infarction (AIM) depends on the extent of irreversibly damaged myocardium and viable tissue due to stunning or hibernation. The aim of the study was to assess the prognostic significance of early echocardiographic parameters of myocardial viability in prediction of late recovery of regional and global ventricular function. Methods. The study prospectively included 40 patients after the first, uncomplicated univessel AIM treated with percutaneous coronary intervention (PCI). Low-dose dobutamine echocardiography (LDDE) was preformed 7-10 days after AIM and follow-up resting echocardiography from 7 to 12 months later. Results. The sensitivity and specificity for the prediction of post revascularisation regional, dyssynergy improvement were 61.29% and 94.59% respectively. The positive and negative predicative values were 90.48% and 74.47% respectively. The number of viable segments (p = 0.01) and extent of contractile reserve (p = 0.01) were univariate, independent predictors of improvement in ejection fraction (EF). From the multivariate stepwise regression analysis contractile reserve was selected as most powerful predictor of late recovery of left ventricular contractile function (p = 0.007). Receiving-operator characteristic curve (ROC) analysis demonstrated that three or more recovered segments were necessary for an improvement of left ventricular ejection fraction (LVEF) ≥ 5% after the revascularisation, with the highest sensitivity, 100% and specificity 56% (p = 0.01). Conclusion. Low-dose dobutamine echocardiography is a powerful predictor of the regional dyssynergy recovery late after AIM treated with PTCA with implantation stent. Late full functional improvement of the left ventricle is related to the extent of contractile reserve and amount of viable tissue. At least three recovered segments are necessary for a significant recovery of the global left ventricular contractility.