Does female gender or hormone replacement therapy affect early or late outcome after carotid endarterectomy?

Objective: Subgroup analyses of the Asymptomatic Carotid Atherosclerosis Study and the North American Symptomatic Carotid Endarterectomy Trial trials have questioned the ability of carotid endarterectomy (CEA) to reduce the risk of stroke in women. The purpose of this study was to test the effect of female gender and estrogen-based hormone replacement therapy on perioperative (30-day) and long-term (5-year) outcomes after CEA. Methods: From 1988 to 1998, 361 CEAs were performed in 326 patients (246 male, 115 female) by a single surgeon. Retrospective data were collected with chart review, and follow-up data were obtained with clinical examination or telephone interview. Follow-up was possible in 95% of patients. Reoperative CEAs and combined aortic or cardiac procedures were excluded. Statistical analysis used life-table methods, Student t test, and Pearson chi(2) tests when appropriate. Results. Age and preoperative risk factors were similar between women and men. CEA was performed for symptomatic (50% female, 42% male) and asymptomatic carotid stenosis (50% female, 58% male; P = .19). Perioperative (30-day) stroke rate was similar for women and men (3.6% female, 1.2% male; P = .13). No perioperative strokes occurred in asymptomatic patients. With previous stroke or transient ischemic attack, a trend was seen towards an increased perioperative stroke rate in women (7.0% female, 2.8% male; P = .25). Long-term follow-up showed a similar trend in the 5-year stroke rate in symptomatic patients (7.0% female, 2.8 male; P = .23). The stroke-free survival rate was not significantly different between genders (87% female, 75% male; P = .58). Reoperation was performed for asymptomatic recurrent carotid stenosis in five men (2.3%) and two women (1.9%; P = .84). Interestingly, the use of estrogen-based hormone replacement therapy in women showed a trend toward increasing stroke rate at 30 days (1.2% versus 8.7%; P = .08) and at 5 years (2.3% versus 8.7%; P = .16). Conclusion: This retrospective study confirms that CEA provides long-term reduction in stroke risk and improved stroke-free survival rates in both men and women. However, women with previous neurologic symptoms and those using hormone replacement therapy appear to be at higher stroke risk at the time of surgery.