Mortality Associated With Carotid Endarterectomy for Asymptomatic Stenosis
To the Editor:
Kragsterman et al reported on the long-term survival after carotid endarterectomy for asymptomatic stenosis in a population-based study.1 They state that the long-term survival from randomized trials is not yet available. We reported on the risk of death associated with asymptomatic carotid stenosis from the prospective randomized trial, VA Cooperative Study 167 on Asymptomatic Carotid Stenosis, in 1993.2
In our report, we studied the risk factors for mortality in 444 male patients. At entry to the trial, patients were judged to be healthy enough to be randomized to operative intervention and were judged to be free of any disease that would preclude a minimal 5-year life expectancy after randomization. Our patients were followed for an average of 4 years. Thirty-seven percent of patients died during the follow-up, whereas 10% experienced a stroke. The risk of death was the same for the operative and nonoperative groups. Multivariate analysis demonstrated that 3 risk factors were significantly associated with an increased risk of mortality: diabetes, abnormal ECG and claudication. Patients with 2 or 3 of these risk factors demonstrated 4-year mortality rates of 45% and 53% respectively. This was significantly higher than patients with none of these risks (odds ratio=2.95 and odds ratio=4.06 respectively).
The study by Kragsterman et al validates our finding that cardiac disease, diabetes and peripheral vascular disease are predictors of decreased long-term longevity. These studies are evidence that asymptomatic carotid stenosis is a marker for generalized vascular disease. At best, carotid endarterectomy for asymptomatic carotid stenosis is a local treatment for a generalized disease. The data from these studies tend to indicate that aggressive risk factor management, especially for patients with more than one of these risk factors, is a more important factor in long-term survival.