Prognostic impact of significant non-infarct-related left main coronary artery disease in patients with acute myocardial infarction who receive a culprit-lesion percutaneous coronary intervention

BACKGROUND: Infarct-related left main coronary artery disease (LMCAD) is associated with an increased cardiac mortality in the setting of acute myocardial infarction (AMI). However, the prevalence and prognostic impact of significant (≥50% stenosis) non-infarct-related LMCAD in patients with AMI have not yet been elucidated. METHODS: We prospectively analyzed 7655 AMI patients who had undergone a percutaneous coronary intervention (PCI) in the Korea Acute Myocardial Infarction Registry from November 2005 to January 2008. We compared major adverse cardiac events (MACEs) in AMI patients with non-infarct-related LMCAD and those without LMCAD. RESULTS: Of 99 (1.3%) non-infarct-related LMCAD patients, 40 patients had undergone PCI due to their lesions on the left main coronary artery. The incidences of all-cause death, cardiac death, recurrent myocardial infarction, and composite of MACE except repeat revascularization were higher in patients with non-infarct-related LMCAD at 12 months. In Cox proportional hazard analysis for the prediction of MACE at 12 months, the hazard ratio of LMCAD was 2.189 (95% confidence interval 1.230-3.896, P=0.008). In subgroup analysis, there was no significant cumulative difference between patients who had undergone non-infarct-related left main coronary artery PCI and those who did not undergo PCI at 1 and 12 months. CONCLUSION: The significant, non-infarct-related LMCAD in patients with AMI remains a major adverse prognostic indicator even after receiving optimal culprit-lesion PCI.