Anticoagulation after hemorrhagic transformation in acute cardioembolic ischemic stroke

BackgroundThe safety and efficacy of anticoagulation in the presence of hemorrhagic transformation (HT) in cardioembolic acute ischemic stroke (AIS) remain uncertain. MethodsThis retrospective study enrolled patients presenting with cardioembolic AIS within 48 hours at a tertiary stroke center between January 2011 and August 2023. Patients who developed HT during hospitalization and underwent follow-up imaging were included, focusing on those with hemorrhagic infarction or parenchymal hematoma type 1. Primary outcomes were HT exacerbation on follow-up imaging and 3-month modified Rankin Scale (mRS) distribution shift, comparing anticoagulation therapy (AC), antiplatelet therapy (APT), and drug discontinuation (NM). The safety outcome was symptomatic intracerebral hemorrhage (sICH) occurrence. ResultsAmong 763 patients with HT (mean age 74.6{+/-}8.9 years, 48.1% male), AC was associated with a higher incidence of HT exacerbation compared to APT (adjusted OR 0.48, 95% CI 0.29-0.80, p-value =0.005). However, AC demonstrated improved 3-month mRS outcomes versus APT (adjusted OR 0.63, 95% CI 0.43-0.92, p-value =0.017) and NM (adjusted OR 0.38, 95% CI 0.26-0.55, p-value <0.001). sICH occurred in 5% of cases overall, with rates of 1.5%, 2.1%, and 11.7% in the AC, APT, and NM groups, respectively (adjusted OR for NM vs. AC: 3.93, 95% CI 1.18-13.16, p-value =0.026). ConclusionIn cardioembolic AIS patients with HT, excluding those with PH-2, anticoagulation may lead to radiological exacerbation without increasing sICH risk, while potentially improving functional outcomes. These findings suggest that the presence of HT should not necessarily preclude the use of anticoagulation therapy in this patient population.