Impact of Direct Oral Anticoagulant Levels on Functional Independence Following Endovascular Thrombectomy in Patients With Atrial Fibrillation

Abstract

BACKGROUND In direct oral anticoagulant (DOAC) users with stroke due to large artery occlusion, endovascular thrombectomy is an effective treatment when intravenous thrombolytic therapy is unsuitable. The purpose of this study is to investigate the association between emergent DOAC levels and endovascular thrombectomy outcomes. METHODS Participants with atrial fibrillation, who had a premorbid modified Rankin Scale score of ≤3 and had undergone endovascular thrombectomy for acute stroke, were enrolled. Drug levels upon hospital arrival were measured in the prestroke DOAC users. Head noncontrast computed tomography and computed tomographic angiography images were used to quantify thrombus permeability. The primary outcome was functional independence at 3 months (modified Rankin Scale 0–2 or a return to premorbid status for patients with a premorbid modified Rankin Scale of 3). RESULTS The study included 250 patients (antithrombotic agent nonusers, 42.0%; oral anticoagulant users, 34.0%; and antiplatelet users, 24.0%). The primary outcomes did not differ among the 3 groups. Among oral anticoagulant users, 78.8% were DOAC users. Of the 59 DOAC users with available drug level measurements, 62.7% had low levels (<50 ng/mL). Low‐level patients were less likely to achieve functional independence than high‐level patients (adjusted odds ratio, 0.26 [0.08–0.87]). Compared with antithrombotic nonusers, oral anticoagulant users with therapeutic anticoagulation were more likely to achieve functional independence (adjusted odds ratio, 2.83 [1.18–6.78]), whereas those with inadequate anticoagulation did not. Symptomatic intracerebral hemorrhage occurred in 3 DOAC users in the low‐level group (8.1%), 1 DOAC user in the high‐level group (4.5%), and 4 antithrombotic nonusers (3.8%). Thrombus permeability was similar between antithrombotic nonusers and low‐ or high‐level DOAC users. CONCLUSION Among patients who underwent DOAC therapy and endovascular thrombectomy, those with low DOAC levels were less likely to achieve functional independence. Furthermore, oral anticoagulant users with therapeutic anticoagulation displayed better functional outcomes than antithrombotic nonusers.