Objective: We assessed the outcomes of intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) patients on dual antiplatelet therapy prior to stroke onset.
Methods: We analyzed prospectively collected data from the Safe Implementation of Treatments in Stroke (SITS) International Stroke Thrombolysis Register on consecutive IVT-treated AIS patients during a 7-year period (2010-2017). In propensity score matched groups of patients with dual antiplatelet pretreatment and no antiplatelet pretreatment, we compared: (1) symptomatic intracerebral hemorrhage (SICH), according to SITS Monitoring Study (MOST), European Cooperative Acute Stroke Study (ECASS) II, and National Institute of Neurological Disorders and Stroke (NINDS) definitions; (2) 3-month mortality; (3) 3-month favorable functional outcome (FFO; modified Rankin Scale [mRS] scores = 0-1); (4) 3-month functional independence (FI; mRS scores = 0-2); and (5) distribution of the 3-month mRS scores. Dual antiplatelet pretreatment was defined as all possible combinations among aspirin, clopidogrel, dipyridamole, and any other antiplatelet.
Results: Propensity score matching resulted in 2 groups of 1,043 patients each, balanced for all baseline characteristics. In the propensity score matched analysis, the 2 groups had comparable (p > 0.017 using Bonferroni correction for multiple comparisons) SICH rates according to SITS-MOST (2.9% vs 1.5%, 95% confidence interval [CI] = -0.03 to -0.01), ECASS II (5.2% vs 4.4%, 95% CI = -0.03 to 0.01), and NINDS (7.7% vs 6.6%, 95% CI = -0.03 to 0.01) definitions. No differences in the 3-month mortality (17.9% vs 16.6%, 95% CI = -0.05 to 0.02), FFO (45.6% vs 46.0%, 95% CI = -0.04 to 0.05), FI (59.2% vs 60.7%, 95% CI = -0.03 to 0.06), or distribution in 3-month mRS scores (2 [1-4] vs 2 [0-4], 95% CI = -0.29 to 0.09) were documented between the 2 groups.
Interpretation: Given that patients on dual antiplatelet pretreatment have similar SICH, 3-month mortality rates, and functional outcomes compared to patients with no antiplatelet pretreatment, dual antiplatelet pretreatment history should not be used as a reason to withhold IVT in otherwise eligible AIS patients. Ann Neurol 2018;83:89-97.
© 2018 American Neurological Association.