The Proportion of Preventable Thrombectomy Procedures with Improved Atrial Fibrillation Stroke Prevention

Background: Large vessel occlusion (LVO) strokes can in part be prevented with better atrial fibrillation (AF) stroke prevention strategies; thus we evaluated the rate of AF in patients presenting with acute LVO strokes undergoing mechanical thrombectomy (MT) and assessed patterns of oral anticoagulant (OAC) use prior to the index stroke. Methods and Results: We identified 347 MT cases from February 2015 to September 2018. A retrospective chart review was conducted to identify patient sociodemographics, presence of AF, use of anticoagulation, stroke severity, CHA₂DS₂-VASc scores, and functional outcomes. AF was present in 161 (46%) cases. Patients with AF were older (mean 76 ± 11 years vs. 66 ± 15 years) and more likely to be female (56% vs. 46%) with higher rates of hypertension, dyslipidemia, heart failure and smoking. Of the 100 patients with known AF, 59 were not on anticoagulation prior to the index stroke. Of 39 patients with known AF on OAC, 57% were not therapeutic on warfarin and 20% were not taking prescribed direct OACs. A total of 72 (21%) thrombectomy cases were performed on patients with known AF who were not effectively anticoagulated. After multivariate adjustments, there was no significant difference in modified Rankin Scale score at discharge, in-hospital mortality, or symptomatic intracranial hemorrhage between the AF and non-AF groups. Conclusion: In our study, 21% of patients with LVO stroke had known AF and were not effectively anticoagulated. Improved stroke preventive measures could potentially reduce the occurrence of stroke and avoid unnecessary procedures for patients with AF.