"Blueprinting" thrombogenicity and antithrombotic drug response at the bedside in patients presenting emergently with symptoms of acute stroke.

Early assessment of thrombogenicity and antithrombotic drug effects may be important for therapeutic decision making in patients presenting with acute stroke. In this prospective, single center, pilot study, a bedside thrombelastography assay (TEG6s) was used to measure thrombogenicity and antithrombotic drug response in serial patients presenting emergently with symptoms of acute stroke (n = 90). TEG6s measures were compared against diagnosis obtained by NIH Stroke Scale/Score and imaging. Acute ischemic stroke (AIS) was diagnosed in 30 patients, intracerebral hemorrhage (ICH) in 19, transient ischemic attack (TIA) in 10 and stroke mimic (SM) in 31. Patients with AIS had a higher prevalence of A-Fib (33.3% vs. 11.6%, p = 0.01), and ACE inhibitor use (56.3% vs. 21.6%, p < 0.001) compared to combined non-AIS group. Time to initial clot formation (R) was shorter in AIS vs. TIA, ICH, and SM (p < 0.05). Comparing patients with AIS and combined non-AIS group the AUC for R was 0.83 (cut point of ≤ 4.8, sensitivity = 67%; specificity = 84%, p < 0.001). In AIS patients, 46% had suboptimal response (< 30% MAAA inhibition) to aspirin and 80% of patients on P2Y12 therapy had high platelet reactivity (> 50% ADP-induced platelet aggregation). Patients receiving tissue plasminogen activator had significant reduction in clot strength and near complete lysis at 30 min which normalized within 2 h after treatment (p < 0.001 for both). The rapid bedside measurement of thrombogenicity and antithrombotic drug effects is feasible in patients presenting with symptoms of acute stroke. Our preliminary data suggest that AIS is associated with faster ex-vivo clot formation, and poor antiplatelet response. Future study of the TEG6s to "blueprint" hemostasis is warranted in the stroke population.

Duke Scholars

Author Paul Alfred Gurbel Medicine, Clinical Pharmacology