Abstract TP416: Comparative Effectiveness of Addition of Antiplatelet to Oral Anticoagulant in Acute Ischemic Stroke With Atrial Fibrillation

Abstract

Introduction: Atrial fibrillation (AF) and large artery diseases (LAD) share several risk factors and often coexist in the same patient. Optimal treatments for acute ischemic stroke (AIS) patients with concomitant AF and LAD have not been extensively studied so far. Objective: This study aimed to compare the effectiveness of the addition of antiplatelet (AP) to oral anticoagulant (OAC) with that of OAC alone in AIS with AF according to the LAD. Methods: Using a multicenter stroke registry, acute (within 48h of onset) and mild-to-moderate (NIHSS score ≤15) stroke patients with AF were identified. Propensity scores using IPTW were used to adjust baseline imbalances between the OAC+AP group and the OAC alone group in all patients and in each subgroup by LAD. The primary outcome was major vascular events, defined as the composite of recurrent stroke, MI, and all-cause mortality at up to 3 months after index stroke. Results: Among the 5469 patients (age, 72±10yrs; male, 54.9%; initial NIHSS score, 4 [2-9]), 79.0% (n=4323) received OAC alone, and 21.0% (n=1146) received OAC+AP. By weighted Cox proportional hazards analysis, a tendency of increasing the risk of 3-months primary composite events in the OAC+AP group vs the OAC alone (HR 1.36 [0.99-1.87], p=0.06), with significant interaction with treatments and LAD (Pint=0.048). Briefly, among patients with moderate-to-severe large artery stenosis, tendency of decrease in 3-months primary composite events of the OAC+AP group, compared with OAC alone group, was observed (HR 0.54 [0.17-1.70]), whereas among patients with complete occlusion, the OAC+AP group markedly increased the risk of 3-months composite events (HR 2.00 [1.27-3.15]), compared with the OAC alone group. No interaction between direct oral anticoagulant and warfarin on outcome was observed (Pint=0.35). Conclusion: In conclusion, treatment with addition of AP to OAC had a tendency to increase the risk of 3-months vascular events, compared with OAC alone in AIS with AF. However, the effects of antithrombotic treatment could be modified according to the LAD, with substantial benefits of OAC alone in subgroup of large artery occlusion. Our results address the need for the further study to tailor the optimal treatment in AIS with concomitant AF and LAD.