Thromboelastography Defines Late Hypercoagulability After TBI (P5.328)

OBJECTIVE:To determine whether thromboelastography could identify a late hypercoagulable state after TBI, defined by elevations in TEG parameters: maximal amplitude (MA), thrombin generation (TG), G value (G), and alpha angle (αA). BACKGROUND:The coagulopathy associated with traumatic brain injury (TBI) is comprised of both a hypo- and hypercoagulable phenotype. The mechanism and duration of the coagulopathy remains unclear. DESIGN/METHODS:Patients with moderate-severe TBI, defined as a GCS 2-point worsening, admitted between 1/2012 - 8/2013 were enrolled in this prospective cohort study. TEG profiles were obtained between 0-24 hours (T1), 24-48h (T2), 48-96h (T3) and greater than 96h (T4) after admission. Early TEG was defined as 0-48h, late TEG was defined as >48h. RESULTS: 33 patients and 15 control subjects were studied. 25/33 (76%) patients were men and median age was 47 years (range 18-85). When compared to controls, study patients had higher MA values at T3 [70 mm (6.2) versus 64 mm (6.6); p=0.03] and T4 [71 mm (6.5) versus 64 mm (6.6); p=0.005]. Thrombin generation was also more elevated in study patients at T3 [838 mm/min (77) versus 764 mm/min (80); p=0.02] and T4 [868 mm/min (80) versus 764 mm/min (80); p=0.002]. G values showed a similar relationship at T3 [12 d/cm2 (4) versus 9 d/cm2 (2.5); p=0.03] and T4 [13.4 d/cm2 (3.7) versus 9 d/cm2 (2.5); p=0.002]. In addition, early TEG compared to late TEG was significant for MA (p=0.0003), TG (p= 0.0002), and G (p=0.0005). There was a linear increase of MA by 2.9 mm daily (p=0.001) and TG by 36.5 mm/min per day (p=0.0001) when clustered by pairs in linear regression. Alpha angle was not statistically significant at any timepoint. CONCLUSIONS:The data suggest that there is a delayed hypercoagulable state observed after TBI. The hypercoagulable state may reflect excessive platelet activity, however, the exact mechanism remains elusive. Disclosure: Dr. Massaro has nothing to disclose. Dr. Doerfler has nothing to disclose. Dr. Nawalinski has nothing to disclose. Dr. Driscoll has nothing to disclose. Dr. Ju has nothing to disclose. Dr. Patel has nothing to disclose. Dr. Nyirjesy has nothing to disclose. Dr. Quattrone has nothing to disclose. Dr. Frangos has nothing to disclose. Dr. Maloney-Wilensky has nothing to disclose. Dr. Siman has nothing to disclose. Dr. Grady has nothing to disclose. Dr. Stein has nothing to disclose. Dr. Kasner has received personal compensation for activities with Pfizer Inc, Novartis, AstraZeneca Pharmaceuticals, Parexel, Brainsgate, Medtronic, Inc., and Boehringer Ingelheim. Dr. Kasner has received personal compensation in an editorial capacity for Up To Date. Dr. Kasner has receied research support from WL Gore & Associates, Acorda, and Asubio. Dr. Kumar has received research support from Haemonetics.