Liberal versus restrictive transfusion thresholds for patients with symptomatic coronary artery disease

Abstract

Background Prior trials suggest it is safe to defer transfusion at hemoglobin levels above 7–8 g/dL in most patients. Patients with acute coronary syndrome may benefit from higher hemoglobin levels. Methods We performed a pilot trial in 110 patients with acute coronary syndrome or stable angina undergoing cardiac catheterization and a hemoglobin < 10 g/dL. Patients in the liberal transfusion strategy received one or more units of blood to raise the hemoglobin level ≥ 10 g/dL. Patients in the restrictive transfusion strategy were permitted to receive blood for symptoms from anemia or for a hemoglobin < 8 g/dL. The predefined primary outcome was the composite of death, myocardial infarction, or unscheduled revascularization 30 days post randomization. Results Baseline characteristics were similar between groups except age (liberal-67.3, restrictive-74.3). The mean number of units transfused was 1.6 in the liberal group and 0.6 in the restrictive group. The primary outcome occurred in 6 patients (10.9%) in the liberal group and 14 (25.5%) in the restrictive group (risk difference= 15.0%; 95% confidence interval of difference 0.7% to 29.3%; p=0.054 and adjusted for age p=0.076). Death at 30 days was less frequent in liberal group (n=1, 1.8%) compared to restrictive group (n=7, 13.0%; p=0.032). Conclusions The liberal transfusion strategy was associated with a trend for fewer major cardiac events and deaths than a more restrictive strategy. These results support the feasibility of and the need for a definitive trial.