Abstract WP168: Anticoagulation Therapy In Endovascular Thrombectomy Patients With Large Vessel Occlusion Due To Cardioembolism

Abstract

Introduction: In ischemic stroke patients, cardioembolism, predominantly due to atrial fibrillation (AF), is a leading preventable cause of large vessel occlusion (LVO). Despite proven efficacy, inadequate oral anticoagulant (OAC) therapy continues to be a major problem in patients with AF, mechanical heart valves and other potential sources of emboli. Aim: To determine rates of cardioembolic LVO, the adequacy of OAC, and the association of OACs with clinical outcomes in LVO patients treated with endovascular thrombectomy (EVT). Methods: Trial of Org 10172 in Acute Stroke Treatment classification was used to determine stroke etiology in consecutive patients treated with EVT. Pre-stroke indication for OAC and the adequacy of anticoagulation were determined for patients with cardioembolic LVO. The primary outcome was 3-month functional independence (modified Rankin Scale score 0-2). Secondary outcomes included early neurological recovery (reduction in National Institutes of Health Stroke Scale score ≥8 points, or score of 0-1 at 24-hours), symptomatic intracranial hemorrhage, and 3-month mortality and modified Rankin Scale score. Results: Between January 2015 and December 2020, 784 patients were treated with EVT. There were 416 patients (213 men; mean±SD age 67.1±15.9) with cardioembolic LVO, including 221 (53.1%) prevalent AF, 99 (23.8%) incident AF, 48 (11.5%) mechanical heart valve, 10 (2.4%) cardiomyopathy-related LVO, 10 (2.4%) left ventricular thrombus-related LVO and 11 (2.6%) patent foramen ovale-related LVO patients. There was adequate anticoagulation in 8 (16.7%) mechanical heart valve patients. Of the 191 prevalent AF patients with pre-stroke indications for OAC, 59 (30.9%) patients had adequate anticoagulation, and were less likely to have internal carotid artery occlusion (6.8% versus 18.9%, P =0.03) and more likely to achieve functional independence (OR=1.97 [95% CI 1.01-3.83]; P =0.04) than those with inadequate anticoagulation. Conclusion: Over half of EVT treated patients had cardioembolic LVO. Only one-third of patients with an indication for OAC at the time of LVO were adequately anticoagulated. This suggests that up to one in five patients with LVO requiring EVT may have been prevented with adequate anticoagulation.