The use of myocardial contrast echocardiography in the assessment of left ventricular function recovery after primary percutaneous coronary intervention in the setting of acute myocardial infarction.

Background: Despite successful reperfusion therapy of acute myocardial infarction and complete restoration of infarct-related artery patency, the improvement of systolic function in long-term outcome depends on preserved microvasculature integrity. Myocardial contrast echocardiography (MCE) is a useful technique for identification of viable myocardium.

Aim: To assess the value of real-time myocardial contrast echocardiography (rt-MCE) in prediction of left ventricular function improvement in patients with anterior wall acute myocardial infarction as well as selection of the optimal cut-off value for the number of dysfunctional segments with preserved complete perfusion, in order to predict the global left ventricular function improvement during one-month observation.

Methods: Rt-MCE was performed in 74 patients (50 men, aged 58+/-11 years) with anterior wall myocardial infarction, treated with primary percutaneous coronary intervention (PCI) within 12 hours from the onset of symptoms. After estimation of regional contractility disturbances and global systolic function of the left ventricle, rt-MCE was performed with contrast assessment of dysfunctional segments (normal contrast pattern=2, heterogeneous=1, lack of contrast=0). Regional perfusion score index (RPSI) was calculated by adding the perfusion indices and dividing by the number of dysfunctional segments.

Results: Of a total of 1184 visualised segments, 344 (29.1%) were dysfunctional (189 hypokinetic, 155 akinetic). Contractility improvement was observed in 192 segments (preserved viability in 105 hypokinetic and 37 akinetic segments). In a group of 44 patients with systolic function improvement, 34 of them had preserved viability, and in a group of 30 patients without LVEF improvement, in 22 of them myocardium viability was not observed. Sensitivity, specificity and accuracy of rt-MCE in prediction of left ventricular global improvement were 72.7%, 73.3% and 73%, respectively, whereas in prediction of regional function improvement these values were 73.9%, 77% and 75.5%, respectively.

Conclusion: Rt-MCE performed in the early phase of myocardial infarction enables the prediction of left ventricular regional and global function improvement in patients treated with primary PCI.