Comparison of TIMI Frame Count and TIMI Myocardial Perfusion Grade in Assessment of Myocardial Reperfusion after Primary Angioplasty for Acute Myocardial Infarction

ABSTRACT

BACKGROUND AND OBJECTIVES: The eventual goal of reperfusion therapy, for an acute myocardial infarction (MI), is rapid and complete reperfusion into the myocardium beyond the epicardial artery. The recently designed TIMI frame count (TFC) and myocardial perfusion grade (TMPG) can be used to define the myocardial tissue perfusion. This study was undertaken to compare the TFC and TMPG for the assessment of myocardial reperfusion following primary angioplasty in patients with an acute anterior wall infarction. SUBJECTS AND METHODS: 33 patients, who admitted for acute myocardial infarction, between January 1998 and March 2001, were the subjects of this study. The subjects all underwent successful primary angioplasty on the LAD, with TIMI III flow. The ECGs, performed on admission and 1 hr after the angioplasty, were compared, the extent of the resolution of the ST elevation assessed. The TFC and TMPG were analyzed by 2 different observers using the coronary angiograms performed immediately and 7 days after the angioplasty. A retrospective analysis of the clinical events at the hospital, and the major coronary events during a follow-up of more than 6 months after discharge were performed. RESULTS: The subjects were divided into 3 groups, completely recovered (n=11) and incompletely recovered (n=12) and not recovered (n=10), according to extent of the resolution of the ST elevation. There were no differences between the groups in their baseline characteristics. The TFC in the completely recovered group was significant lower (p=0.02, p=0.01) than the other patient groups immediately after the angioplasty, but there was no significant difference (p=0.28, p=0.32) in the TFC between the 3 patients groups 7 day after the angioplasty. The TMPG in the completely recovered group was consistently higher than in the other patient groups, both immediately and 7 days after the angioplasty. Five patients, who developed major coronary events during 16 month follow-up, tended to show no, or an incomplete resolution, of their ST elevation. They also showed significantly lower TMPG compared with the others, both immediately, and 7 days, after PTCA, but no significant difference at all in the TFC. CONCLUSION: The TMPG was closely associated with the rate of the ST elevation resolution in both the early and late periods after the primary angioplasty in acute MI, indicating that the TMPG is a better marker for the evaluation of myocardial reperfusion after primary angioplasty than the TFC. The low TMPG was observed to be related with a higher major coronary event rate, suggesting its usefulness as a predictor of long-term prognosis.