Abstract 12099: Relationship of Blood Transfusion with In-Hospital Mortality: A Propensity Matched Analysis of Consecutive Acute Myocardial Infarction Patients from 57 US Hospitals
Background: Blood transfusion is controversial for anemic patients with acute myocardial infarction (AMI), with some prior studies reporting increased transfusion-associated mortality risk. We examined the relationship of transfusion with in-hospital mortality in a large contemporary database of consecutive, unselected AMI patients.
Methods: Among 34937 consecutive AMI admissions, patients receiving at least 1 packed red cell transfusion were compared to those who were not transfused. Using 45 disease severity, comorbidity, laboratory and in-hospital treatment variables, we fit a propensity model for likelihood of blood transfusion. Patients with and without transfusion were then propensity matched. Adequacy of matching was assessed using standardized differences. We used conditional logistic regression to identify the association between transfusion and in-hospital mortality.
Results: 1778 patients (5.1%) had at least 1 transfusion. In unadjusted analyses, transfusion was associated with higher in-hospital mortality (OR 2.05, 95% CI 1.76-2.40). The majority of patients (90.9%) with and without transfusion had non-overlapping propensity scores (Figure). After propensity matching those with overlapping scores, blood transfusion was associated with a reduced risk of in-hospital death (OR 0.75, 95% CI 0.60-0.94).
Conclusions: Blood transfusion was associated with lower in-hospital mortality risk after propensity matching in this large AMI cohort. The majority of patients could not be matched due to non-overlapping propensity scores, suggesting reports of increased mortality with transfusion may reflect selection bias not fully addressed by multivariable regression or propensity analyses of datasets with less intensive collection of in-hospital disease severity, comorbidity and treatment variables. Randomized trials are needed to study the impact of transfusion on mortality during AMI.
- © 2012 by American Heart Association, Inc.