Abstract DP330: Oral Anticoagulation With or Without Antiplatelet Therapy After Atherothrombotic Versus Cardioembolic Stroke in Patients With Nonvalvular Atrial Fibrillation and Atherosclerotic Cardiovascular Disease

Background: Antiplatelet therapy is recommended for prevention of recurrent stroke in patients with atherothrombotic brain infarction (ATBI). However, the benefit-risk balance of adding antiplatelet therapy to oral anticoagulant (OAC) in patients with concomitant nonvalvular atrial fibrillation (NVAF) is unclear. We compared ischemic and bleeding outcomes of OAC plus antiplatelet versus OAC alone in ATBI and cardioembolic stroke (CE) in patients with NVAF and atherosclerotic cardiovascular disease (ASCVD). Methods: ATIS-NVAF was a randomized trial of patients with NVAF and ASCVD after ischemic stroke or transient ischemic attack assigning OAC alone or OAC plus antiplatelet therapy. In this post-hoc analysis, we included those with a final etiologic diagnosis of ATBI or CE. The primary outcome was recurrent ischemic stroke. Secondary outcomes were major or clinically relevant non-major bleeding and all-cause mortality. Results: A total of 175 patients were included (ATBI: n=82, CE: n=93). In the ATBI group, recurrent ischemic stroke occurred in 14.8 % in the combination arm and 19.1% in the monotherapy arm (HR, 0.74; 95% CI, 0.23–2.33; p=0.61). In the CE group, recurrent ischemic stroke occurred in 13% in the combination arm and 7.9% in the monotherapy arm (HR, 1.63; 95% CI, 0.36–7.27; p=0.53). In ATBI patients, hemorrhagic events tended to be more frequent in the combination arm than in the monotherapy arm (25.4% vs 8.7%); the Cox model showed a trend toward higher risk (HR, 3.36; 95% CI, 0.91 –12.4; p=0.07). All-cause mortality did not differ significantly between groups. Conclusions: In patients with ATBI and NVAF, adding antiplatelet therapy to OAC increased bleeding without evidence of reduced recurrent ischemic stroke or mortality. These findings do not support routine combination therapy for secondary prevention in this subgroup