Abstract W P103: Rates and Predictors of Five Year Survival in Asymptomatic Medicare Beneficiaries Undergoing Carotid Revascularization

Abstract

Background: Current American Heart Association guidelines recommend carotid revascularization for asymptomatic patients based on co-morbid conditions and life expectancy. Objective: To determine the rates and predictors of five year survival in elderly patients with asymptomatic carotid artery stenosis who underwent either surgical or endovascular treatment. Methods: The study cohort included a representative sample of fee-for-service Medicare beneficiaries aged ≥65 years who underwent endovascular or surgical treatment for asymptomatic carotid artery stenosis with post-procedure follow-up of 3.4 (±1.7) years. The rates of 5 year survival were determined using Kaplan Meir survival methods. Cox proportional hazards analysis was used to assess the relative risk (RR) of all-cause mortality for patients in presence of selected co-morbidities including ischemic heart disease, chronic renal failure, and atrial fibrillation after adjusting for potential confounders such as age, gender, race/ethnicity and procedure type. Results: A total of 22177 patients with asymptomatic carotid artery stenosis were treated with either endovascular (n=2144) or surgical treatment (n=20033). The overall estimated 5 year survival rate was 95.3% (95% CI 95.0-95.6 %); and 95.5% and 93.8% in patients treated with surgical and endovascular treatments, respectively. After adjusting for potential confounders, relative risks of all-cause five year mortality was significantly higher among patients with atrial fibrillation (relative risk [RR] 1.9, 95% confidence interval [CI] 1.6-2.2) and those with chronic renal failure (RR 2.1, 95% CI1.7-2.6). Concurrent ischemic heart disease did not affect the all-cause mortality (RR 1.1, 95% CI0.9-1.3). Conclusion: Risks and benefits must be carefully weighed prior to carotid revascularization in elderly patients with asymptomatic carotid artery stenosis who have concurrent atrial fibrillation or chronic renal failure.