Anaemia and Prognosis in Acute Coronary Syndromes: a Systematic Review and Meta-analysis

OBJECTIVE: This meta-analysis was conducted to summarize the association between anaemia and outcomes in patients with acute coronary syndromes (ACS). METHODS: MEDLINE (R), Cochrane Library, OVID and EMBASE databases were searched to identify studies that examined the effect of anaemia on mortality or other adverse events (heart failure, cardiogenic shock or major bleeding). RESULTS: Nineteen studies met the final inclusion criteria (total number of patients 241293). The risks of short-term mortality (odds ratio [OR] 2.77; 95% confidence interval [CI] 2.09, 3.65), long-term mortality (OR 2.03; 95% CI 1.52, 2.71), heart failure (OR 1.96; 95% CI 1.47, 2.62), cardiogenic shock (OR 1.95; 95% CI 1.04, 2.64) and major bleeding (OR 4.28; 95% CI 1.05, 17.14) were increased in patients with anaemia, compared with patients without anaemia. Anaemia was also associated with a higher risk of mortality (adjusted hazard ratio 1.49, 95% CI 1.24, 1.79). CONCLUSIONS: These study findings suggest that anaemia can be used to identify patients with ACS who are at a high risk of death or adverse events, and it may become a promising risk stratification factor in ACS.