Context It is unclear if blood transfusion in anemic patients with acute coronary
syndromes is associated with improved survival.
Objective To determine the association between blood transfusion and mortality
among patients with acute coronary syndromes who develop bleeding, anemia,
or both during their hospital course.
Design, Setting, and Patients We analyzed 24 112 enrollees in 3 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.
Main Outcome Measure Thirty-day mortality.
Results Of the patients included, 2401 (10.0%) underwent at least 1 blood transfusion
during their hospitalization. Patients who underwent transfusion were older
and had more comorbid illness at presentation and also had a significantly
higher unadjusted rate of 30-day death (8.00% vs 3.08%; P<.001), myocardial infarction (MI) (25.16% vs 8.16%; P<.001), and death/MI (29.24% vs 10.02%; P<.001)
compared with patients who did not undergo transfusion. Using Cox proportional
hazards modeling that incorporated transfusion as a time-dependent covariate,
transfusion was associated with an increased hazard for 30-day death (adjusted
hazard ratio [HR], 3.94; 95% confidence interval [CI], 3.26-4.75) and 30-day
death/MI (HR, 2.92; 95% CI, 2.55-3.35). In the landmark analysis that included
procedures and bleeding events, transfusion was associated with a trend toward
increased mortality. The predicted probability of 30-day death was higher
with transfusion at nadir hematocrit values above 25%.
Conclusions Blood transfusion in the setting of acute coronary syndromes is associated
with higher mortality, and this relationship persists after adjustment for
other predictive factors and timing of events. Given the limitations of post
hoc analysis of clinical trials data, a randomized trial of transfusion strategies
is warranted to resolve the disparity in results between our study and other
observational studies. We suggest caution regarding the routine use of blood
transfusion to maintain arbitrary hematocrit levels in stable patients with
ischemic heart disease.