Abstract 13666: The Association of White Blood Cell Count and Bleeding in Acute Coronary Syndrome: An Insight Into the Atlas ACS-TIMI 51 Trial

IntroductionAn elevated white blood cell (WBC) count is associated with an increased risk of ischemic events among acute coronary syndrome (ACS) patients, but the association between WBC count and bleeding in ACS patients is not well established. The aim of this analysis is to assess the association between WBC count and the occurrence of bleeding in patients on rivaroxaban.MethodsThis is a post-hoc analysis of the ATLAS ACS-TIMI 51 trial. A subset of subjects had a WBC count measurement at baseline (N=14,231, 91.6%). A multivariable cox proportional hazard model was constructed to determine if there is an association between WBC count at baseline and a composite of Thrombolysis in Myocardial Infarction (TIMI) major and minor bleeds at 30 days. Variables included in this model had a univariate association with the outcome with a p-value 11 x 10/L) and included in a multivariable analysis with the same parameters selected in the previous model. WBC count was measured in a central laboratory. A cut off value of 11 x 10/L was determined based on previous studies.ResultsOf the patients in the study, 1,282 (9.01%) had a WBC count greater than 11.0 x 10/L. An increased risk of bleeding per a unit increase in WBC at baseline was observed at 30 days (Adjusted HR 1.09, 95% CI 1.01-1.17, p=0.019). When dichotomized (WBC ≤11 x 10/L vs > 11 x 10/L), higher WBC was also associated with an increased risk of bleeding by 30 days (HR 2.06, 95%CI 1.04-4.09, p=0.040) (Figure).ConclusionsWBC count was associated with an increased risk of the composite bleeding endpoint by 30 days.