Age modifies the efficacy and safety of carotid artery revascularization procedures

Several randomized clinical trials have shown that carotid artery endarterectomy (CEA) is safer than carotid artery stenting (CAS) in the elderly. However, those studies were limited by their strict inclusion criteria that might make their findings inapplicable to real-world practice. Therefore, the aim of this study was to evaluate the association of age with the efficacy of CEA and CAS in a population-based registry.

The Vascular Quality Initiative database was inquired (2005-2017). The primary outcome was 30-day and 2-year stroke and a combined outcome of stroke/death. Logistic regression models with age-by-treatment interaction term were fitted adjusting for patients' characteristics. Restricted cubic spline modelling was also implemented. Two-year events were assessed via survival analysis methods.

Overall, 89,853 patients were included, 26.9% were less than 65 years of age, 39.1% were 65 to 74 years of age, and 34.1% were 75 years of age or older. The CAS-to-CEA odds of 30-day stroke became significant at age 56.5 and doubled at age 72.5 years. After CEA, the risk of stroke rose by 1.3-fold when age increased from 76 to 85 (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.05-1.62). Yet after CAS, when age increased from 65 to 71 years, the OR of stroke was 1.36 (95% CI, 1.04-1.76); from 71 to 76 years, the OR was 1.47 (95% CI, 1.10-1.96), and from 76 to 85 years the OR was 1.38 (95% CI, 1.06-1.81). The superiority of CEA with increasing age extended to 2 years after the procedure. The CAS-to-CEA 2-year hazard of stroke was significant at age 53 and it doubled at 71.5 years.

In this multicenter registry, we confirmed the effect modification role that age plays in the safety and efficacy of carotid revascularizations. The risk-adjusted effectiveness of CAS was particularly sensitive to patient age, whereas CEA performance was relatively stable across various age strata. Of note, the observed effect was more pronounced and a decade earlier than what previously reported in the ideal setting of a randomized clinical trial.