Reduced morbidity and mortality following carotid endarterectomy: The value of preoperative cardiac screening

Carotid endarterectomy can be recommended for stroke prophylaxis when performed with low perioperative cardiac morbidity and mortality. In this study the authors evaluate the effectiveness of a cardiac screening protocol using dipyridamole-thallium scintigraphy to identify and treat coexistent coronary artery disease (CAD). The authors reviewed the medical records of 164 patients undergoing carotid endarterectomy between 1988 and 1993 at the John L. Doyne Hospital and at the Zablocki Veterans Administration Hospital in Milwaukee, Wisconsin. Results of the preoperative cardiac evaluations and the incidence of perioperative cardiac events were recorded. Forty patients without any evidence of cardiac disease by history or electrocardiogram went on to surgery without further screening. Eight patients underwent coronary catheterization without dipyridamole-thallium scan, owing to the severity of their cardiac symptoms. A cardiology consultation and dipyridamole-thallium scan were obtained preoperatively in the remaining 116 patients with a history of CAD. Of these 116 patients, 62 (53.4%) were diagnosed as normal, Thirty-five (30%) scans demonstrated reversible reperfusion defects, leading to preoperative coronary angiography in 17 patients and to cardiac revascularizations in 8. Nineteen (16.4%) scans demonstrated a fixed perfusion defect; 3 of these patients under-went coronary catheterization, leading to cardiac revascularization in 1 patient. Of 2 patients (1.7%) who suffered a postoperative myocardial infarction, 1 patient had a fixed perfusion defect and 1 was found to have a two-vessel disease on coronary catheterization. There were no perioperative deaths. In the followup period (15.9 months; range one to sixty), no cardiac deaths occurred. With this treatment algorithm using selective dipyridamole-thallium scan evaluation, perioperative and long-term cardiac morbidity and mortality can be minimized.