CLINICAL QUESTION: Does a blood transfusion in anemic patients with acute coronary syndrome improve survival?
STUDY DESIGN: Cohort (prospective)
SETTING: Inpatient (any location) with outpatient follow-up
SYNOPSIS: Blood transfusions are routinely performed for patients with ischemic heart disease developing anemia acutely during hospitalization, but evidence of benefit is uncertain. The investigators analyzed data from 24,112 subjects enrolled in 3 large international trials of patients with acute coronary syndromes, evaluating various antithrombotic regimens. Analysis was limited to patients with complete data on transfusion and bleeding occurrence. All endpoints were evaluated (by individuals blinded to treatment group assignment) as to whether subjects received blood transfusions. Because blood transfusion was a postrandomization event left to the discretion of the treating clinician, associations between transfusion and primary and secondary endpoints were evaluated using multiple logistic regression techniques to evaluate independent variables and control for confounding factors.
A total of 2401 patients (10%) underwent at least 1 blood transfusion during their hospitalization. Transfusion was independently related to an increased risk of death at 30 days (hazard ratio= 3.94; 95% confidence interval [CI], 3.26–4.75). The predicted probability of death was higher when a transfusion was performed for hematocrit values higher than 25%, with no benefit or risk detected for transfusions given for values lower than 25%. A previous trial (N Engl J Med 2001; 345:1230–1236) has shown a benefit of selective transfusion in elderly patients hospitalized with acute coronary syndrome and anemia (hematocrit ≤33%) on admission (not acutely developing during hospitalization).
