Five-year outcomes in patients with anemia on admission undergoing a coronary intervention for acute myocardial infarction in Koreans: propensity score matching analysis

Abstract

BackgroundAcute myocardial infarction (AMI) is a progressive disease in Korea and active treatment strategies can improve the clinical outcomes. In the CADILLAC trial, anemia on admission was associated strongly with adverse outcomes and increased mortality in AMI. However, it remains controversial whether anemia on admission is an independent poor prognostic factor of long-term clinical outcomes in AMI patients undergoing a percutaneous coronary intervention with a drug-eluting stent in Koreans.Patients and methodsA total of 1143 AMI patients undergoing percutaneous coronary intervention with drug-eluting stent at Korea University Guro Hospital between 2005 and 2015 were enrolled. Anemia on admission was defined as hemoglobin levels of less than 13g/dl in men and less than 12g/dl in women using the WHO's criteria. Patients were divided into two groups (472 patients with anemia and 671 patients without anemia). The primary endpoint was major adverse cardiac events (MACE) up to 5 years including death, myocardial infarction, and revascularization.ResultsTo adjust for confounding factors, we carried out a propensity score matching analysis. Two matched groups (300 pairs, n=600 patients) were generated and their baseline characteristics were balanced. During the 5-year clinical follow-up, patients with anemia had a higher incidence of MI [hazard ratio (HR): 2.137, 95% confidence interval (CI): 1.074-4.254], target vessel revascularization (HR: 1.641, 95% CI: 1.004-2.682), and total MACE (HR: 1.427, 95% CI: 1.012-2.614).ConclusionAMI patients with anemia on admission had higher incidence of MI, target vessel revascularization, and total MACE over the 5-year follow-up.