Background and purpose: Carotid endarterectomy has been shown to be beneficial in patients with high-grade carotid stenosis and ipsilateral transient ischemic attack or stroke. This benefit will be realized only if the operation is performed safely. We sought to determine the extent to which clinically significant adverse events occurring after carotid endarterectomy can be predicted from clinical data available before surgery.
Methods: Eleven hundred sixty patients were randomly selected from all patients who underwent carotid endarterectomy and were discharged during the calendar years 1988, 1989, and 1990 in 12 academic medical centers in 10 states. Clinical data abstracted from hospital charts were analyzed retrospectively. A model was developed and validated to predict the occurrence of stroke, myocardial infarction, or death during the postoperative period of hospitalization.
Results: Eight patients (6.9%) suffered at least one adverse event. Rates for individual complications were as follows: death, 1.4%; nonfatal stroke, 3.4%; nonfatal myocardial infarction, 2.1%; and nonfatal stroke or death, 4.8%. Significant predictors of adverse events were age 75 years or older, symptom status (ipsilateral symptoms versus asymptomatic or nonipsilateral symptoms), severe hypertension (preoperative diastolic blood pressure of greater than 110 mm Hg), carotid endarterectomy performed in preparation for coronary artery bypass surgery, history of angina, evidence of internal carotid artery thrombus, and internal carotid artery stenosis near the carotid siphon. The presence of two or more of these risk factors was associated with a nearly twofold increase in risk of an adverse event (relative risk, 1.7; 95% confidence interval, 1.0 to 3.0).
Conclusions: Clinical data can be used to stratify patients undergoing carotid endarterectomy according to risk of postoperative in-hospital stroke, myocardial infarction, or death.