Risk factors for perioperative myocardial ischemia in carotid artery endarterectomy

OBJECTIVE: To identify variables associated with perioperative myocardial ischemia in patients undergoing carotid artery endarterectomy (CEA). DESIGN: Prospective, observational study. SETTING: University-affiliated hospital operating room and intensive care unit. PARTICIPANTS: One hundred twenty-eight consecutive patients who underwent CEA during a 7-year period. INTERVENTIONS: Patients had general anesthesia with sevoflurane or isoflurane. CEA was performed by standard methods with shunting if clinically indicated. Holter electrocardiogram (ECG) monitoring was performed during surgery and 24 hours after surgery. MEASUREMENTS AND MAIN RESULTS: The incidence of perioperative myocardial ischemia was examined, and perioperative risk factors were analyzed. Nineteen patients (15%) showed significant perioperative ECG abnormalities indicative of myocardial ischemia (10 patients during surgery, 12 patients after surgery, and 3 patients both during and after surgery). Multivariate analysis showed perioperative myocardial ischemia to be significantly associated with a history of angina (odds ratio, 11.68; 95% confidence interval, 2.64-51.70) and a history of hypertension (odds ratio, 14.08; 95% confidence interval, 1.51-131.04). CONCLUSION: The data indicate that perioperative myocardial ischemia defined as an ECG abnormality does not often occur in patients undergoing CEA. However, angina and hypertension may be important risk factors warranting further investigation.