Carotid endarterectomy: Characterization of recent increases in procedure rates

Introduction: Recent increases in the rate of carotid endarterectomies (CEAs) have been attributed to results of clinical trials demonstrating efficacy when CEA is performed in centers of excellence. Subsequent population-based data suggest that trial results may not be matched in the community. This study was undertaken to characterize trends in CEA procedure rates after the dissemination of trial data and to describe any change in patient outcomes with population-based data from a single state. Methods: Hospital administrative data on CEAs from 1992 to 1996 (n = 45,744) were obtained for the state of Florida. Annualized CEA rates per 100,000 Florida residents were analyzed to determine trends in patient age, sex, admission type, size of hospital beds, ownership type and teaching status, and annual hospital and surgeon CEA volume. Outcomes were examined to track trends in complication rates. Results: The annual number of CEA procedures increased 74% from 63.7 per 100,000 residents per year to 110.8 per 100,000 residents per year between 1992 and 1996. A single large increase occurred during the second half of 1994 when CEAs increased 73.5% from 16.6 per 100,000 residents per quarter to 28.8 per 100,000 residents per quarter after a clinical alert on benefits to CEAs in asymptomatic patients. Over 5 years, there were significant trends toward more nonemergent admissions, and more procedures were performed in high-volume hospitals and by high-volume surgeons. Procedure rates in both women and very elderly patients increased more than 70%, which was in step with younger patients and men. The incidence of inpatient stroke and death declined over the 5-year period, whereas the rate of perioperative myocardial infarction remained constant. Conclusions: Experience from Florida indicates that CEA rates increased as results of the Asymptomatic Carotid Artery Study disseminated. Trial results have been broadly interpreted to include women and very elderly patients. More patients are being referred to busier hospitals and to high-volume surgeons, which should continue to result in better patient outcomes.