Background: Thrombelastography (TEG) provides a global, dynamic measure of coagulation. We examined the effect of antiplatelet (AP) medications on coagulation in patients with acute stroke as measured by TEG.
Methods: We reviewed prospectively collected data on patients presenting with acute ischemic stroke (AIS) and spontaneous intracerebral hemorrhage (ICH) between 2009 and 2014. Patient demographics and baseline TEG values were compared among 4 different drug use groups: aspirin only, clopidogrel only, both aspirin and clopidogrel, and no AP. Multivariable regression models were conducted to compare the differences in TEG components.
Results: A total of 202 patients were included, 139 with AIS and 63 with ICH. Forty-eight (24%) patients were taking aspirin alone, 12 (6%) were taking clopidogrel, 16 (8%) dual AP, and 126 (62%) no AP. Dual AP use was associated with prolonged mean R (time to initiate clotting) of 5.5 minutes as compared to no AP use (4.6 minutes, P = .04). Additionally, mean maximal amplitude (MA; final clot strength) and angle (rate of clot formation) were decreased in the dual AP group (MA = 59.3 mm, angle = 57.8°) as compared to the no AP group (MA = 64.5 mm, angle = 64.5°; P = .04 and P = .01, respectively). Patients on single AP therapy (either aspirin or clopidogrel) did not differ from those on no AP therapy in any TEG parameters measured.
Conclusion: Dual AP therapy is associated with a detectable coagulopathy which may have implications in the management of patients with AIS and hemorrhagic stroke. The effects of single AP therapy may not be demonstrated by TEG.
Keywords: antiplatelet; aspirin; clopidogrel; coagulation; stroke; thrombelastography.