Myocardial perfusion in ST-elevation myocardial infarction treated successfully with primary angioplasty

OBJECTIVES: To study myocardial perfusion in ST-elevation myocardial infarction (STEMI) treated successfully with primary angioplasty. Additionally, to evaluate the predictive value of perfusion on subsequent infarct size. DESIGN: Fifty patients with acute STEMI and restoration of normal epicardial flow after primary angioplasty were included in the study. TIMI myocardial perfusion (TMP) grades were determined at the end of the procedure. Contrast enhanced magnetic resonance imaging (MRI) including first-pass perfusion and delayed enhancement imaging were performed within five days and after three months. RESULTS: The patients were divided into two groups: A=TMP 0-1, B=TMP 2-3. The early MRI showed significantly reduced myocardial perfusion in the infarct zone compared to remote myocardium in both groups (p<0.001), but the reduction was more pronounced in group A. The infarct sizes were smaller (p=0.0017) and the ejection fractions higher (p=0.0001) in group B than in group A at follow-up. CONCLUSIONS: In STEMI, early impairments in myocardial perfusion were observed in spite of successful treatment with angioplasty. Marked early impairments in perfusion were associated with larger infarct sizes on MRI after three months.