VESS03 - The Elevated Stroke/Death Rates among Asymptomatic Patients Undergoing Carotid Stenting in the Pacific Northwest Are Associated with High-Risk Patient Selection

Objectives: To ensure patient benefit, current guidelines recommend treatment of asymptomatic patients with carotid stenosis only if stroke/death rates less than 3% can be achieved. However, in the Pacific Northwest region of the Vascular Quality Initiative (VQI) elevated stroke/death rates have been reported at semiannual meetings. This study aims to characterize regional and center-specific outcomes for transcarotid artery revascularization (TCAR) and transfemoral carotid artery stenting (TF-CAS) and investigate potential underlying drivers.

Methods: A retrospective review of asymptomatic patients undergoing TCAR and TF-CAS in the VQI for the Pacific Northwest region from 2016 to 2022 was performed. The primary outcome was the composite of stroke or death within 30-days of index hospitalization. Overall regional outcomes and de-identified center-specific outcomes were assessed. A high stroke/death rate was defined as greater than 3%. Demographics, comorbidities, and operative risk factors were then compared between centers with high and low stroke/death rates.

Results: 1,154 asymptomatic patients across 27 centers underwent carotid stenting in the Pacific Northwest from 2016 to 2022, of which 886 (77%) underwent TCAR and 268 (23%) underwent TF-CAS. The overall stroke/death rates were 2.5% and 3.0% for TCAR and TF-CAS, respectively. Among centers with stroke/death rates above 3%, for both TCAR and TF-CAS, all were in the top half of centers by volume. When patients undergoing TCAR were assessed, those treated at centers with high stroke/death rate underwent revascularization at higher volume centers (12 vs. 7 cases per year, p=0.03) which treated fewer patients with >80% stenosis (42% vs. 52%, p< 0.01) and more patients with high-risk anatomy (42% vs. 35%, p=0.01), and high risk physiology as defined by an ASA class of 4 (25% vs. 18%, p< 0.01) Among patients treated with TF-CAS patients, those treated at centers with high stroke/death rate were more likely to have missing data for lesion stenosis (26% vs. 3.3%, p< 0.01), high-risk anatomy (64% vs. 49%, p=0.03), and high risk physiology as defined by an ASA class of 4 (24% vs. 10%, p< 0.01).

Conclusions: High stroke/death rates in the Pacific Northwest appear to be driven by the selection of high-risk patients with less than 80% stenosis. Decreasing the frequency of carotid revascularization in asymptomatic patients with very high physiologic risk including those with ASA class 4 and those with less than 80% stenosis may offer opportunity for improved outcomes.