Randomized controlled trials are needed to determine appropriate blood transfusion strategies in patients with acute coronary syndromes

Setting and Patients: 24,112 patients from three large international trials of patients with acute coronary syndromes (the GUSTO IIb, PURSUIT, and PARAGON B trials). Patients were grouped according to whether they received a blood transfusion during the hospitalization. The association between transfusion and outcome was assessed using Cox proportional hazards modeling that incorporated transfusion as a time-dependent covariate and the propensity to receive blood, and a landmark analysis. Outcomes: The primary outcome was 30-day all-cause mortality, with a secondary composite endpoint of 30-day mortality or myocardial infarction (MI).