Prognostic interaction between age and sex on outcomes following carotid endarterectomy

Background: The aim of this study was to assess the prognostic interaction between age and sex on peri-operative and follow-up outcomes following elective carotid endarterectomy (CEA) for asymptomatic and symptomatic carotid stenosis. Patients and methods: A retrospective review of all patients admitted to a single vascular unit who underwent elective CEA between January, 2015 and December, 2019 was performed. The primary endpoints of the study were overall survival (from index operation) and cumulative stroke rate at thirty days. Results: A total of 383 consecutive patients were included in this study; of these 254 (66.4%) were males. At baseline, males were younger (mean age 73.4±11 vs. 76.3±10 years, p=.01) and with lower proportion of octogenarians (20.4% vs. 28.7%, p=.05). The rate of stroke in symptomatic and asymptomatic patients (males vs. females) were as follows: a) whole cohort 1.9% vs. 2% (p=1.00) and 2.7% vs. 1.3% (p=.66), respectively; b) 80 years old 3.7% vs. 0% (p=1.00) and 4% vs. 5.9% (p=1.00), respectively; c) ≤80 years old 1.2% vs. 3.3% (p=.47) and 2.5% vs. 0% (p=.55), respectively. The 3-year survival estimates were significantly lower for males (84% vs. 92%, p=.03). After stratification by age groups, males maintained inferior survival rates in the strata aged ≤80 years (85% vs. 97%, p=.005), while no differences were seen in the strata aged ≥80 years (82% vs. 79%, p=.92). Using multivariate Cox proportional hazards, age (HR: 2.1, 95% CI: 1.29-3.3, p=.002) and male gender (HR: 2.5, 95% CI: 1.16-5.5, p=.02) were associated with increased hazards of all-cause mortality. Conclusions: In this study of elective CEA for asymptomatic and symptomatic carotid stenosis, similar peri-operative neurologic outcomes were found in both males and females irrespective of age. Despite being usually older, females have superior long-term survival rates.