Myocardial Contrast Echocardiography Versus Dobutamine Echocardiography for Predicting Functional Recovery After Acute Myocardial Infarction Treated With Primary Coronary Angioplasty

Objectives. Wesought to comparemyocardial contrast echocardiography with low dose dobutamine echocardiography for predicting l-menth recovery ofventricular function in acute myocardial infarction treated with primary coronary angioplasty. Background. The relation between myocardial perfusion and contractile reservein patients withacute myocardial infarction, in whom anterograde flow is fully restored without significantresidual stenosis, is still unclear. Methods. Thirty patients with acute myocardial infarction treated successfully with primary coronaryangioplastyunderwent intracoronary contrast echocardiography before and after angioplasty and dobutamine echocardiography 3 days after the index infarction. One month later, two-dimensional echocardiography and coronary angiography were repeated in all patients and contrast echocardiography in 18 patients. Results. Mter coronary recanalization, 26 patients showed myocardial reperfusion within the risk area, although 4 did not. At l-monfh follow-up, all patients had a patent infarct-related artery without significantrestenosis.Both left ventricular ejection fraction and wall motion score index within the risk area signif- icantly improved in the patients with reperfusion ([mean ± SD] 38 ± 8%vs. 48 ± 12%, P < 0.005; and 2.35 ± 0.5 vs, 2 ± 0.6, p < 0.001, respectively), but not in those with no reflow. Of the 72 nonperfused segments before angioplasty, 27 showed functional improvement at follow-up. Myocardialcontrast echocardiography had a sensitivity and a negative predictive value similar to dobutamineechocardiograpby in predicting late functional recovery (96% vs. 89% and 89% vs. 93%, respectively), but a lower specificity (18% vs.91%, p < 0.001), positive predictive value (41% vs,86%, p < 0.001) and overallaccuracy(47% vs.90%, p < 0.001). Conclusions. Microvascularintegrity is a prerequisite for myocardial viability after acute myocardial infarction. However, contrast enbancement shortly after recanalization does not necessarilyimplya late functional improvement. Thus, contractile reserve elicited by lowdose dobutamine is a more accurate predictor of regional functional recovery after reperfused acute myocardial infarction than microvascular integrity.