Preoperative thallium scanning, selective coronary revascularization, and long-term survival after carotid endarterectomy

Background and Purpose - Long-term survival in patients after carotid endarterectomy (CEA) is determined mainly by their concomitant cardiac disease. We tested to determine whether preoperative thallium scanning (PTS) and subsequent selective coronary revascularization (CR), by either percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG), improve long-term survival after CEA. Methods - Two hundred twenty-six of 255 consecutive patients (88%) undergoing CEA from 1990 to 1996 had PTS. Those with significant reversible defects on PTS were referred for coronary angiography and possible CR. Patients who had undergone PTS were divided into the following 4 groups: group 1, normal or mild defects on PTS; group 2, moderate-severe fixed and/or reversible defects in patients who did not undergo CR; group 3, patients who had CR secondary to their PTS results; and group 4, patients who had CR in the past that was not related to the PTS. Perioperative data were prospectively recorded, and data on long- term survival and cardiac and neurological complications were collected. Results - Seventy-seven patients (34%) had preoperative coronary angiography, and 42 (19%) had subsequent CR: preoperative PTCA or CABG in 24, combined CEA+CABG in 10, and post-CEA CABG in 8 patients. No deaths resulted from the coronary angiography, CR, or CEA. Six patients had perioperative nonfatal myocardial infarction and 8 had stroke. During the follow-up (40±23 months), 47 patients (18%) died, 31 (66%) from cardiac disease and 4 (8.5%) from stroke. Independent predictors of long-term overall mortality were diabetes mellitus, preoperative T-wave inversion on ECG, lower-extremity arterial disease, and history of neurological symptoms [exp(β)=3.5, 3.4, 2.5, and 2.4; P=0.0003, 0.0004, 0.01, and 0.04, respectively]. In addition, preoperative moderate-severe thallium defect without CR (group 2) independently predicted long-term cardiac mortality [exp(β)=2.8; P=0.04]. Patients with preoperative CR (group 3) had long-term survival rate similar to that of group 1 and significantly better than that of group 2 (P=0.02). Conclusions - PTS predicts long-term survival, and selective CR based on the thallium results improves the survival rate of patients undergoing CEA.