Authors: Samuel Mansour; Joanna Wycech; Alexander Tymchak; Adam Zuviv; Maggie Crawford; Alexander Fokin, MD, PhD; Ivan Puente, MD, FACS (Boca Raton, FL)

Introduction Antiplatelet therapy (APT) use has increased due to our aging population and increased incidence of cardiovascular disease. While effective in treating cardiovascular disease, APT may increase risk of intracranial hemorrhage (ICH) in traumatic brain injury (TBI). Our study seeks to assess adverse events in patients ondual APT versus those on single APT. Methods This IRB approved retrospective cohort study included 346 TBI patients on pre-injury ASA, Clopidogrel or both who were delivered to a level 1 trauma center between 1/1/2015 and 3/30/2018. Patients were divided into 2 groups by pre-injury APT: Group A was taking either aspirin (ASA) only or Clopidogrel only (n=259), and Group B was taking both ASA and Clopidogrel (n=87). Injury Severity Score (ISS), Glasgow Coma Score (GCS), Rotterdam computed tomography (CT) score, Marshall CT score, incidence of ICH, midline shift, platelet function and status, need for neurosurgical intervention, re-admission rate and mortality were compared. Results Group B had higher mean ISS (12.1 vs 14.1; p=0.02), incidence of ICH (84.2% vs 93.1%; p=0.04), midline shift (5.8% vs 12.6%; p=0.04), Platelet Function Assay (PFA)-100 epinephrine (173.8 vs 224.0; p=0.001), TEG-PM % inhibition adenosine diphosphate (ADP) (36.4 vs 51.8; p=0.003), and need for neurosurgical intervention (2.7% vs 11.5%; p=0.001) than group A. The two groups had comparable mean age (81.8 vs 80.3), GCS (14.3 vs 13.8), Rotterdam score (2.6 vs 2.6), Marshall score (1.1 vs 1.2), platelet count on admission (208.6 vs 222.7), Partial Thromboplastin Time (26.3 vs 25.7 seconds), Prothrombin Time (1.1 vs 1.2 seconds), readmission rate (5.5% vs 4.6%) and mortality (9.7% vs 12.6%), with all p>0.09. Conclusion Patients on dual APT had increased platelet dysfunction, increased incidence of ICH and need for neurosurgical intervention compared to patients on single APT. This may suggest that increased precautions should be taken with this type of patient.