Association of Sex With the Use and Outcomes of Carotid Revascularization: A Cohort Study

Stroke is a leading cause of death that disproportionately affects women. Treating carotid stenosis with carotid artery stenting (CAS) or carotid endarterectomy (CEA) can prevent ischemic stroke. Yet, the sex-specific use and long-term outcomes of these interventions remain unclear. Thus, we sought to investigate sex-based differences in the treatment and outcomes of carotid stenosis.

We analyzed carotid revascularizations in the Vascular Quality Initiative, a national clinical registry. Patients were linked to Medicare claims to identify long-term outcomes. Our study cohort included patients undergoing index CAS or CEA between 2005 and 2015 who were fee-for-service Medicare beneficiaries aged 65+. The primary exposure was sex, and the primary outcome was stroke. Using log-binomial regression, we estimated the relative risk for CAS treatment accounting for clustering by center. Cox proportional hazards regression was used to estimate the hazard ratio for stroke. We used inverse probability-weighted risk adjustment based on patient demographics, comorbidities, and disease severity for all analyses.

In our cohort of 22 341 eligible patients, 39% were women, 13% underwent CAS, and the median survival time was 2.6 years (interquartile range: 1.0-3.4 years). After risk adjustment, women were less likely to undergo CAS than men (adjusted relative risk, 0.89; [95% CI, 0.83-0.96]; P=0.003). Women undergoing carotid revascularization had a 24% increased risk of stroke (adjusted HR, 1.24; [95% CI, 1.10-1.39]; P=0.001) within 5 years of surgery. The higher stroke rate in women was noted following both carotid endarterectomy (adjusted HR, 1.22; [95% CI, 1.07-1.38]; P=0.003) and CAS (adjusted HR, 1.40; [95% CI, 1.06-1.83]; P=0.014). This effect was most pronounced for symptomatic treatment, where women undergoing CEA had a 3% higher risk-adjusted 5-year cumulative incidence of stroke (13% versus 10%, Gray's P=0.002).

Compared with men, women had a higher incidence of postoperative stroke after carotid revascularization, regardless of treatment type. Sex disparities in postrevascularization stroke rates may give rise to concern given the widespread use of revascularization for managing carotid stenosis.