Distal embolic protection use during transfemoral carotid artery stenting is associated with improved in-hospital outcomes

Despite current guidelines recommending the use of distal embolic protection during transfemoral carotid artery stenting (tfCAS) to prevent periprocedural stroke, there remains significant variation in the routine use of distal filters. We sought to assess in-hospital outcomes in patients undergoing tfCAS with and without embolic protection using a distal filter. We identified all patients undergoing tfCAS in the Vascular Quality Initiative from March 2005 to December 2021 and excluded those who received proximal embolic balloon protection. We created propensity score-matched cohorts of patients who underwent tfCAS with and without attempted placement of a distal filter. Subgroup analyses of patients with failed vs successful filter placement and failed vs no attempt at filter placement were performed. In-hospital outcomes were assessed using log binomial regression, adjusted for protamine use. Outcomes of interest were composite stroke/death, stroke, death, myocardial infarction (MI), transient ischemic attack (TIA), and hyperperfusion syndrome. Among 29,853 patients who underwent tfCAS, 28,213 (95%) had a filter attempted for distal embolic protection and 1640 (5%) did not. After matching, 6859 patients were identified. No attempted filter was associated with significantly higher risk of in-hospital stroke/death (6.4% vs 3.8%; adjusted relative risk [aRR], 1.72; 95% confidence interval [CI], 1.32-2.23; P < .001), stroke (3.7% vs 2.5%; aRR, 1.49; 95% CI, 1.06-2.08; P = .022), and mortality (3.5% vs 1.7%; aRR, 2.07; 95% CI, 1.42-3.020; P < .001). In a secondary analysis of patients who had failed attempt at filter placement vs successful filter placement, failed filter placement was associated with worse outcomes (stroke/death: 5.8% vs 2.7%; aRR, 2.10; 95% CI, 1.38-3.21; P = .001 and stroke: 5.3% vs 1.8%; aRR, 2.87; 95% CI, 1.78-4.61; P < .001). However, there were no differences in outcomes in patients with failed vs no attempted filter placement (stroke/death: 5.4% vs 6.2%; aRR, 0.99; 95% CI, 0.61-1.63; P = .99; stroke: 4.7% vs 3.7%; aRR, 1.40; 95% CI, 0.79-2.48; P = .20; death: 0.9% vs 3.4%; aRR, 0.35; 95% CI, 0.12-1.01; P = .052). tfCAS performed without attempted distal embolic protection was associated with a significantly higher risk of in-hospital stroke and death. Patients undergoing tfCAS after failed attempt at filter placement have equivalent stroke/death to patients in whom no filter was attempted, but more than a two-fold higher risk of strok