Atrial fibrillation is associated with lower likelihood of first-pass effect in thrombectomy for medium vessel occlusion acute ischemic strokes

BackgroundFirst-pass effect (FPE) in endovascular thrombectomy (EVT) is strongly associated with clinically favorable outcomes. Atrial fibrillation (AF)-related strokes have been shown to be associated with greater rates of FPE in acute large vessel occlusions (LVOs). In this study, we aimed to assess the association between AF and achieving FPE in medium vessel occlusions (MeVOs).MethodsA prospectively maintained registry of adult ischemic stroke patients at a comprehensive stroke center between October 2019 and October 2023 was retrospectively screened for inclusion. Patients undergoing EVT for a MeVO were included. Univariable and multivariable logistic regressions with 2500 bootstrap iterations for FPE and mFPE was performed using covariables that were clinically and/or statistically significant. Adjusted odds ratios with 95% confidence intervals (CIs) were reported. Regression performance was assessed using area under the curve (AUC) from receiver operating characteristics curve analysis.Results34.4% of patients with MeVO achieved FPE and 58.2% achieved mFPE. In multivariable logistic regression models, AF was independently associated with lower likelihood of FPE, and AF and prior antiplatelet/anticoagulant use were independently associated with lower likelihood of mFPE. Models for FPE and mFPE had AUCs of 0.80 (95% CI [0.75-0.85]) and 0.86 (95% CI [0.78-0.94]), respectively.ConclusionAF was associated with a significantly lower likelihood of FPE and mFPE in EVT of MeVOs. This may suggest a need to prepare for additional passes and rescue intraprocedural strategies for MeVO in patients with AF.