Combination of anemia and high B-type natriuretic peptide levels is indicative of in-hospital mortality of patients with acute myocardial infarction

Abstract

Background: Anemia is an important factor negatively affecting the prognosis of patients with ischemic heart disease. B-type natriuretic peptide (BNP), a marker of heart failure, is also closely associated with mortality in patients with acute myocardial infarction (AMI). However, a few studies have assessed the relationship between hemoglobin (Hb) and BNP levels in AMI patients with regard to in-hospital prognosis. Methods and results: This study included 567 patients with AMI; their Hb concentrations were determined on admission, and their BNP levels, approximately 7 days after the onset of AMI. The combined effect of these values on in-hospital mortality was evaluated. Patients were classified into 4 groups according to the presence of anemia and their median BNP values. Anemia was defined according to the World Health Organization criteria (hemoglobin levels, <13 g/dL for men and <12 g/dL for women), and the cutoff value for BNP was 174.5 pg/mL for all patients. The incidence of in-hospital mortality for the 4 groups were as follows: nonanemic patients with low BNP levels, 0.4%; nonanemic patients with high BNP levels, 11.3%; anemic patients with low BNP levels, 7.1%; and anemic patients with high BNP levels, 22.4%. Our results indicated that, in-hospital mortality was higher in anemic patients with high BNP levels than in nonanemic patients with low BNP levels (odds ratio, 69.3; 95% confidence interval, 14.5–1243.0; p < 0.0001). Conclusions: Classification based on hemoglobin concentration and BNP levels is useful for predicting in-hospital mortality in patients with AMI.