Usefulness of intravenous myocardial contrast echoardiography in the early left ventricular remodeling in acute myocardial infarction.

The aim of this study was to assess the role of intravenous myocardial contrast echocardiography (IMCE) in the prediction of left ventricular (LV) remodeling in patients with acute myocardial infarction (AMI). Sixty-three patients with AMI, who were successfully treated with acute coronary angioplasty, underwent IMCE and low-dose dobutamine echocardiography during hospital admission. IMCE was graded semiquantitatively on a score of 0 (no visible contrast effect), 0.5 (patchy myocardial contrast enhancement), and 1 (homogenous contrast effect). Patients were considered to have microvascular impairment if <50% of segments within the infarct-related area had score of 1. A mean perfusion score index was calculated for each patient. Patients with a good perfusion at IMCE (IMCE+) showed a lower creatine kinase peak (p = 0.001) and lower creatine kinase-MB (p = 0.01), and a better baseline regional contractile function compared with patients who had negative results at IMCE (IMCE-) (p <0.0001) and a higher amount of myocardial viability at low-dose dobutamine echocardiography (p = 0.03). At follow-up, a higher improvement in regional systolic function (p = 0.0006) was observed in IMCE+ patients, whereas IMCE- patients showed an evident increase in LV end-diastolic volume from baseline to 6-month follow-up (p <0.0001), implying LV remodeling, which has been associated with a higher incidence of adverse cardiac events (p = 0.005). By stepwise multiple regression analysis, microvascular impairment at IMCE was a significant independent predictor of LV remodeling (p <0.0001). Thus, IMCE seems to be an important diagnostic tool, able to predict LV remodeling in patients with AMI.