Perioperative Cardiovascular Morbidity and Mortality

Although the randomized trials discussed previously have demonstrated a protective effect of carotid endarterectomy on ipsilateral stroke, the critical determinants of benefit for any given patient must include the perioperative event rate and expected long-term survival. The perioperative complication rate for carotid endarterectomy needs to be very low (approximately 3% or less) to maintain the beneficial effects of surgery over medical therapy.^[545] A systematic review of 51 studies (1980–1995) reported an overall mortality rate of 1.6% and a risk of stroke or stroke plus death of 5.6% after carotid endarterectomy for symptomatic carotid stenosis.^[558] Another systematic review of 25 studies (1980–1995) reported a 30-day mortality rate of 1.3% for asymptomatic stenosis and 1.8% for symptomatic stenosis.^[559] The overall risk for stroke and death was 3.4% for asymptomatic stenosis and 5.2% for symptomatic stenosis.^[559] The incidence of perioperative stroke is highest for patients diagnosed with stroke, lower for patients with transient ischemic attack, and lowest in asymptomatic patients.^{[560] [561] [562]} Neurologic deficits occur most commonly in patients with poorly controlled preoperative hypertension or in those with hypertension or hypotension postoperatively.^{[563] [564]} More than one half of these deficits occur more than 4 hours postoperatively.^[563] The incidence of perioperative MI in patients undergoing carotid endarterectomy ranges from 0% to 4%.^{[563] [565] [566] [567] [568] [569] [570]} MI is the leading cause of perioperative and late mortality after carotid endarterectomy. Some reports suggest that carotid endarterectomy can be safely performed in the very elderly and those deemed high risk, with combined stroke and death rates comparable to those found in randomized trials (North American Symptomatic Carotid Endarterectomy Trial and Asymptomatic Carotid Artery Study).^{[571] [572] [573]}