Hemoglobin and Change in Hemoglobin Status Predict Mortality, Cardiovascular Events, and Bleeding in Stable Coronary Artery Disease.

Background: Anemia is a predictor of adverse outcomes in acute myocardial infarction. We studied the relationship of hemoglobin, or its change over time, and outcomes in patients with stable coronary artery disease.

Methods: The ProspeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease is a prospective, cohort study of outpatients with stable coronary artery disease (32,901 in 45 countries 2009-2010): 21,829 with baseline hemoglobin levels. They were divided into hemoglobin quintiles and anemia status (anemic or normal at baseline/follow-up: normal/normal; anemic/normal; normal/anemic; anemic/anemic. All-cause mortality, cardiovascular events, and major bleeding at 4-year follow-up were assessed.

Results: Low baseline hemoglobin was an independent predictor of all-cause, cardiovascular, and noncardiovascular mortality, the composite of cardiovascular death/myocardial infarction or stroke and major bleeds (all P <.001; unadjusted models). Anemia at follow-up was independently associated with all-cause mortality (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.55-2.33 for anemic/anemic; 1.87; 1.54-2.28 for normal/anemic; both P <.001), noncardiovascular mortality (P <.001), and cardiovascular mortality (P = .001). Patients whose baseline anemia normalized (anemic/normal) were not at increased risk of death (HR, 1.02; 95% CI, 0.77-1.35), although the risk of major bleeding was greater (HR, 2.06; 95% CI, 1.23-3.44; P = .013) than in those with normal hemoglobin throughout. Sensitivity analyses excluding patients with heart failure and chronic kidney disease at baseline yielded qualitatively similar results.

Conclusions: In this large population with stable coronary artery disease, low hemoglobin was an independent predictor of mortality, cardiovascular events, and major bleeds. Persisting or new-onset anemia is a powerful predictor of cardiovascular and noncardiovascular mortality.