Background: Anemia is common in heart failure (HF), but there is controversy regarding its contribution to morbidity and mortality.

Objective: To examine the association of mild and severe anemia with acute HF severity and mortality.

Methods: Data were prospectively collected for patients admitted to all departments of medicine and cardiology throughout the country during 2 months in 2003 as part of the Heart Failure Survey in Israel. Anemia was defined as hemoglobin (Hb) < 12 g/dl for women and < 13 g/dl for men; Hb < 10 g/dl was considered as severe anemia. Mortality data were obtained from the Israel population registry. Median follow-up was 33.6 months.

Results: Of 4102 HF patients, 2332 had acute HF and available hemoglobin data. Anemia was common (55%) and correlated with worse baseline HF. Most signs and symptoms of acute HF were similar among all groups, but mortality was greater in anemic patients. Mortality rates at 6 months were 14.9%, 23.7% and 26.3% for patients with no anemia, mild anemia, and severe anemia, respectively (P < 0.0001), and 22.2%, 33.6% and 39.9% at one year, respectively (P < 0.0001). Compared to patients without anemia, multivariable adjusted hazard ratio was 1.35 for mild anemia and 1.50 for severe anemia (confidence interval 1.20–1.52 and 1.27–1.77 respectively).

Conclusions: Anemia is common in patients with acute HF and is associated with increased mortality correlated with the degree of anemia.