Distressed Community Index in Patients Undergoing Carotid Artery Stenting in Medicare-Linked Vascular Quality Initiative Registry

Introduction: Patients with high community-level socioeconomic distress have worse cardiovascular outcomes, yet its impact on carotid artery stenting (CAS) outcomes is unknown. We assessed the association between the Distressed Community Index (DCI), a zip-code level measure of community distress, with post-CAS mortality and stroke. Methods: We used the Vascular Quality Initiative database linked with Medicare claims outcomes data to identify patients undergoing CAS between 2015 and 2019. From a time-dependent ROC curve and using Youden index, we classified patients as high community distress if DCI≥65. Thirty-six-month cumulative mortality incidence using Kaplan-Meier by DCI groups, and hierarchical Cox regression with random intercept for site for linear DCI were used. For stroke, we used 36-month cumulative incidence function by DCI groups, and Fine and Gray models accounting for competing risk of death for linear DCI. Models were later adjusted for patient and procedural characteristics. Results: The final complete-case cohort included 8,595 patients (2,580/30% DCI≥65), had a mean age of 74.7 (±7.8) years, was 92.7% white and 97.6% non-Hispanic/Latino. The 36-month cumulative mortality incidence was similar in both groups (26.0% vs 22.5%, P=0.236). A 10-point increase in DCI did not increase mortality risk (unadjusted HR 1.00; 95% CI 0.98-1.03 and adjusted HR 1.01; 95% CI 0.87-1.17). At 36 months the high community distress group experienced higher stroke risk (29.8% vs 22.9%, P=0.008). However, a 10-point increase in DCI did not increase stroke risk (unadjusted sub-HR: 1.01; 95% CI 0.99-1.03, adjusted sub-HR: 1.00; 95% CI 0.98-1.02). Conclusions: In this selective set of patients with underrepresentation of demographic groups, for those who get prioritized to CAS, higher community distress was associated with an increased unadjusted 36-month stroke risk by DCI group. However, a 10-point increase in DCI was nonsignificant regardless of adjustment.