Effect of anemia on short- and long-term outcome in patients hospitalized for acute coronary syndromes.

Anemia is common in hospitalized cardiac patients and is associated with adverse outcomes. The aim of this study was to identify the association of anemia with early and long-term outcomes in patients with acute coronary syndromes (ACSs). Included were 5,304 consecutive patients (73% men, 61 ± 12 years of age) admitted to a coronary care unit from 1985 through 2008 for ACS. According to the World Health Organization, anemia was defined as serum hemoglobin levels <13 g/dl for men and <12 g/dl for women. Anemia was divided into tertiles to compare mild, moderate, and severe anemia to nonanemia. For trend analyses the study population was categorized in 3 groups: 1985 to 1990, 1991 to 2000, and 2001 to 2008. Outcome measurements were all-cause mortality at 30-days and 20 years. Anemia was present in 2,016 patients (38%), of whom 655 had mild anemia, 717 moderate anemia, and 646 severe anemia. Median follow-up duration was 10 years (range 2 to 25). Compared to nonanemia, adjusted hazard ratios (HRs) for mortality at 30 days were 1.40 for moderate anemia (95% confidence interval [CI] 1.04 to 1.87) and 1.67 for severe anemia (95% CI 1.25 to 2.24). At 20 years HRs were 1.13 for moderate anemia (95% CI 1.01 to 1.27) and 1.39 for severe anemia (95% CI 1.23 to 1.56). In addition, survival during hospitalization improved over time. Compared to 1985 to 1990 adjusted HRs were 0.52 for 1991 to 2000 (95% CI 0.41 to 0.66) and 0.36 for 2001 to 2008 (95% CI 0.25 to 0.51). In conclusion, presence and severity of anemia is an important predictor of higher in-hospital and long-term mortality after ACS. In addition, since the 1980s in-hospital outcome of patients with ACS and anemia has improved.