NATIONAL HARBOR, MD. – The 5-year survival rates for patients undergoing carotid endarterectomy for asymptomatic stenosis differ significantly depending on whether they are classified as low, medium, or high risk, according to an analysis of prospectively collected data on more than 4,000 patients.
"Our study is the first of its kind to describe independent predictors of 5-year mortality in this population of patients," Dr. Jessica B. Wallaert said at the Vascular Annual Meeting.
Dr. Wallaert of Dartmouth-Hitchcock Medical Center, Lebanon, N.H., and her colleagues studied factors associated with 5-year survival after carotid endarterectomy (CEA) in patients with asymptomatic internal carotid artery (ICA) stenosis. Whether such patients will benefit from the procedure – especially when they are asymptomatic – depends on their ability to achieve long-term survival. The researchers’ goal was to improve patient selection and create user-friendly tools for surgeons and patients alike to predict the probability of benefiting from this prophylactic surgery.
They analyzed prospectively collected data from 4,294 isolated CEAs that were performed for asymptomatic stenosis across 24 centers in the Vascular Study Group of New England (VSGNE) in 2003-2011. Mortality was determined from the Social Security Death Index. Cox proportional hazard models were used to identify risk factors for mortality within the 5 years after CEA.
Overall 5-year survival was 82%. In multivariate analysis, increasing strata of age, diabetes, smoking history, heart failure, chronic obstructive pulmonary disease, poor renal function (defined as an estimated glomerular filtration rate less than 60 mL/min, or dialysis dependence), and degree of contralateral ICA stenosis were all associated with poorer survival. Statin use, however, predicted improved survival.
Patients who were classified as low (27%), medium (68%), and high (5%) risk on the basis of their number of risk factors had significantly different 5-year survival rates: 94%, 80%, and 51%, respectively.
"More than four out of five asymptomatic patients selected for CEA in the Vascular Study Group of New England achieved 5-year survival, demonstrating appropriate patient selection in our region," she said. However, there are patients with high-risk profiles who are unlikely to survive long enough to realize a benefit of CEA for asymptomatic stenosis.
Dr. Wallaert reported that she had nothing to disclose.