Abstract 2269: Prognostic Value of Blood transfusion in Patients Presenting with an Acute Coronary Syndrome/Non-ST Elevation MI
Background: Anemia has been shown to be an adverse prognosticator in patients presenting with an acute coronary syndrome (ACS)/non-ST-elevation MI. We sought to evaluate the impact of red blood cell (RBC) transfusions on outcomes in this setting.
Methods: We prospectively studied 1410 consecutive patients admitted to a tertiary Veterans Administration hospital with suspicion of an ACS/NSTEMI. Clinical information was determined by medical record abstraction. Anemia was defined as hemoglobin<11.5mg/dl. Outcome measures were 30-day mortality or recurrent MI. Clinical characteristics and outcomes were measured in anemic patients that were transfused versus the non-transfused patients using chi-square tests for categorical variables and the student T-test for continuous variables. Multivariate logistic regression modeling was performed to analyze the relationship between RBC transfusion and adverse outcome.
Results: The study population was predominantly white (76.5%) and male (97.5%). Of these, 370 patients (26.2%) were anemic on admission and 110 (29.73%) of the anemic population had red blood cell transfusion. There were a total of 134 adverse events; 46 (29.4%) in transfused population and 88 (7.0%) in non- transfused population. Patients with anemia (OR=4.1, 95% CI=2.8– 5.9, p<0.001) and blood transfusion (OR=3.1, 95% CI=1.8 –5.2, p<0.001) were significantly more likely to suffer an adverse outcome. This relationship persisted after adjusting for significant univariate variables consisting of age, hypotension on presentation, chronic renal insufficiency, pulmonary edema and elevated troponins (OR=3.4, 95% CI=1.5 –4.7, p<0.001).
Conclusion: Patients presenting with an acute coronary syndrome and anemia are at significantly higher risk of an adverse outcome. This risk increases further in population receiving RBC transfusions during index hospitalization. Further studies are needed to confirm this detrimental role of transfusions in anemic patients presenting with an ACS.