Evaluation of the left ventricular remodeling in patients with myocardial infarction after revascularization with intravenous real-time myocardial contrast echocardiography

Abstract

In order to evaluate the left ventricular remodeling in patients with myocardial infarction after revascularization with intravenous real-time myocardial contrast echocardiography (RT-MCE), intravenous RT-MCE was performed on 20 patients with myocardial infarction before coronary revascularization. Follow-up echocardiography was performed 3 months after coronary revascularization. Segmental wall motion was assessed using 18-segment LV model and classified as normal, hypokinesis, akinesis and dyskinesis. Myocardial perfusion was assessed by visual interpretation and divided into 3 conditions: homogeneous opacification=1; partial or reduced opacification or subendocardial contrast defect=2; contrast defect=3. Myocardial perfusion score index (MPSI) was calculated by dividing the total sum of contrast score by the total number of segments with abnormal wall motion. Twenty patients were classified into 2 groups according to the MPSI: MPSI<or=1.5 as good myocardial perfusion, MPSI>1.5 as poor myocardial perfusion. To assess the left ventricular remodeling, the following comparisons were carried out: (1) Comparisons of left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV) before and 3 months after revascularization in two groups; (2) Comparisons of LVEF, LVESV and LVEDV pre-revascularization between two groups and comparisons of these 3 months post-revascularization between two groups; (3) Comparisons of the differences in LVEF, LVESV and LVEDV between 3 months post-and pre-revascularization (DeltaLVEF, DeltaLVESV and DeltaLVEDV) between two groups; (4) The linear regression analysis between DeltaLVEF, DeltaLVESV, DeltaLVEDV and MPSI. The results showed that the LVEF obtained 3 months after revascularization in patients with MPSI>1.5 was obviously lower than that in those with MPSI<or=1.5. The LVEDV obtained 3 months post-revascularization in patients with MPSI>1.5 was obviously larger than that in those with MPSI<or=1.5 (P=0.002 and 0.04). The differences in DeltaLVEF and DeltaLVEDV between patients with MPSI>1.5 and those with MPSI<or=1.5 were significant (P=0.002 and 0.001, respectively). Linear regression analysis revealed that MPSI had a negative correlation with DeltaLVEF and a positive correlation with DeltaLVESV, DeltaLVEDV (P=0.004, 0.008, and 0.016, respectively). It was concluded that RT-MCE could accurately evaluate the left ventricular remodeling in patients with myocardial infarction after revascularization.