Comparison of TIMI Myocardial Perfusion Grade with Coronary Flow Reserve for Prediction of Recovery of LV Function and LV Remodeling in Acute Myocardial Infarction

ABSTRACT

BACKGROUND AND OBJECTIVES: The TIMI myocardial perfusion (TMP) grade is known as one of the methods to assess the viability of the myocardium in ischemic heart disease. This study was designed to assess the value of TMP grade itself and to evaluate the correlation with coronary flow reserve (CFR) in the prediction of left ventricular remodeling and functional change after percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI). SUBJECTS AND METHODS: We measured CFR and TMP grade after successful elective PCI (diameter stenosis <0%, and TIMI flow 3) in 83 patients (mean age 55+/-1 years, 18 females) with AMI within 7 days of symptom onset. Left ventricular end diastolic volume index (LVEDVI), left ventricular end systolic volume index (LVESVI), ejection fraction (LVEF), and left ventricular regional wall motion score index (LVRWMSI) were assessed by echocardiography just before and at 9 months after angioplasty (mean 9+/-5 months). RESULTS: Although they had achieved (TIMI 0.021) TIMI 3 flow after successful intervention, 27 of 83 patients (32.5%) had impaired myocardial perfusion. After PCI, angiographic TMP grade was well correlated with CFR measured using Doppler wire (TMP 0/1;1.4+/-0.3, TMP 2;1.9+/-0.6, TMP 3;2.2+/-0.4, rs=0.618, p=0.000). Post-PCI TMP grade was significantly related to the change of LVEDVI (r=0.452, p=0.000), LVESVI (r=0.435, p=0.000), LVEF (r=0.281, p=0.010) and LVRWMSI (r=0.328, p=0.036). CONCLUSION: The TMP grade, a simple angiographic method, might be useful as a predictor of LV volume and functional change in AMI. In the cardiac catheterization laboratory, it could simply replace CFR for the assessment of myocardial viability in patients who receive an elective PCI within 7 days of AMI onset.