Effect of coronary occlusion site on angiographic and clinical outcome in acute myocardial infarction patients treated with early coronary intervention.

In acute myocardial infarction that is treated with thrombolysis, proximal coronary artery occlusion is associated with worse prognosis, irrespective of the infarcted artery. Primary percutaneous coronary intervention (PCI) is currently the treatment of choice for ST-segment elevation acute myocardial infarction. Therefore, we evaluated the prognostic significance of proximal versus distal coronary artery occlusion in patients with acute myocardial infarction that was treated with primary PCI. Between 1994 and 2001, patients with a first acute myocardial infarction that was treated with primary PCI were analyzed. A lesion was considered proximal if it was located proximal to the first diagonal branch in the left anterior descending coronary artery (LAD), the first marginal obtuse branch in the left circumflex coronary artery, and the first right acute marginal branch in the right coronary artery. Lesions distal of these side branches were considered distal. In total, 1,468 patients were analyzed. Left ventricular ejection fraction (LVEF) for proximal LAD lesions was lower than that for distal ones (37 +/- 11% vs 42 +/- 11%, p <0.0001). Adjusted relative risk of 3-year mortality for proximal versus distal LAD was 4.04 (95% confidence interval 1.95 to 8.38). In patients with infarcts related to the right or left circumflex coronary artery, no significant association between lesion location and LVEF or mortality was seen. No difference was seen in adjusted 3-year mortality between distal LAD and non-LAD-related infarcts (p = 0.145). In conclusion, our analysis shows that, even in patients with acute myocardial infarction that is treated with primary PCI, infarcts related to the proximal LAD have the worst 3-year survival and lowest residual LVEF compared with distal LAD or non-LAD-related infarcts.