Has evidence changed practice?: appropriateness of carotid endarterectomy after the clinical trials.

OBJECTIVE: To assess how appropriateness of and indications for carotid endarterectomy (CEA) have changed following the publication of several large international randomized controlled trials (RCTs) designed to rationalize use of CEA.
METHODS: The New York Carotid Artery Surgery Study (NYCAS) is a population-based cohort study of all CEAs performed on elderly patients from January 1998 through June 1999 in New York State. Detailed clinical data were abstracted from medical charts to assess indications for and appropriateness of surgery using a list of 1,557 indications for CEA developed by national experts using RAND appropriateness methods. Deaths and strokes within 30 days of surgery were ascertained and confirmed by two physicians.
RESULTS: Among the 9,588 patients, the mean age was 74.6 years and 93.6% had 70 to 99% carotid stenosis. Nearly three-quarters of patients (72.3%) underwent CEA for asymptomatic stenosis, 18.6% for TIA, and 9.1% for stroke. Overall, 87.1% of operations were done for appropriate reasons, 4.3% for uncertain reasons, and 8.6% for inappropriate reasons (vs 32% inappropriate before the RCTs, p < 0.0001). Among procedures judged inappropriate, the most common reasons were high comorbidity in asymptomatic patients (62.2%), operating after a major stroke (14.2%), or for minimal stenosis (10.5%). Among asymptomatic patients, those with high comorbidity had over twice the risk of death or stroke compared to those without high comorbidity (7.13% vs 2.69%, p < 0.0001).
CONCLUSIONS: Since publication of the randomized controlled trials, there has been a reduction in the proportion of patients undergoing carotid endarterectomy (CEA) for inappropriate reasons. The shift toward many asymptomatic patients undergoing CEA is concerning because the net benefit from surgery for these patients is low and is reduced further for patients with high comorbidity.