Intravenous Thrombolysis for Ischemic Stroke Patients on Dual Antiplatelets

ObjectiveWe assessed the outcomes of intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) patients on dual antiplatelet therapy prior to stroke onset.
MethodsWe analyzed prospectively collected data from the SITS International Stroke Thrombolysis Register (SITS‐ISTR) on consecutive IVT‐treated AIS patients during a seven‐year period (2010‐2017). In propensity‐score matched groups of patients with dual antiplatelet pretreatment and no antiplatelet pretreatment we compared: 1) SICH, according to SITS‐MOST, ECASS II and NINDS definitions, 2) 3‐month mortality, 3) 3‐month favorable functional outcome (FFO; 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 or any other antiplatelet.
ResultsPropensity‐score matching resulted in two groups of 1043 patients each, balanced for all baseline characteristics. In the propensity‐score matched analysis the two groups had comparable (p>0.017 using Bonferroni correction for multiple comparisons) SICH rates according to SITS‐MOST (2.9% vs. 1.5%; 95%CI:‐0.03,‐0.01), ECASS II (5.2% vs. 4.4%; 95%CI:‐0.03,0.01) and NINDS (7.7% vs. 6.6%; 95%CI:‐0.03,0.01) definitions. No differences in the 3‐month mortality (17.9% vs. 16.6%; 95%CI:‐0.05,0.02), FFO (45.6% vs. 46.0%; 95%CI:‐0.04,0.05), FI rates (59.2% vs. 60.7%; 95%CI:‐0.03,0.06) or the distribution in 3‐month mRS‐scores [2 (1‐4) vs. 2 (0‐4); 95%CI:‐0.29,0.09] were documented between the two 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.