Influence of Hemoglobin Level on In-Hospital Prognosis in Patients With Acute Coronary Syndrome

Abstract

Many patients with acute coronary syndrome (ACS) suffer from anemia. The objective of this study was to determine the influence of the admission hemoglobin level and the post-admission fall in hemoglobin level on short-term prognosis during hospitalization. This retrospective study involved 542 high-risk ACS patients who were admitted during 2005. The hemoglobin level was recorded on admission and at least every 24 hours thereafter, with anemia being defined according to WHO criteria. Logistic regression modeling was used to assess the relationship of the admission hemoglobin level and the fall in hemoglobin level to all-cause mortality and cardiogenic shock during hospitalization. During follow-up (median time, 7 days), the incidence of cardiogenic shock or mortality was 6.9% (37 patients). Anemia was present in 147 patients (27.1%) at admission, increasing to 266 patients (49.1%) during hospitalization (P< .0001). After adjusting for a range of variables, independent associations were found between the occurrence of adverse events and both the admission hemoglobin level (odds ratio [OR]=1.4 for each 1 g/dL below normal; 95% confidence interval [CI], 1.1-1.8; P=.003) and a fall in hemoglobin level >1.8 g/dL (OR=5.4; 95% CI, 1.5-18.8; P=.009). In high-risk ACS patients both the admission hemoglobin level and a subsequent fall in hemoglobin level >1.8 g/dL were associated with an increased risk of all-cause mortality or cardiogenic shock.