Impact of diabetes mellitus on characteristics of carotid plaques and outcomes after carotid endarterectomy

Published results for carotid endarterectomy (CEA) in symptomatic and asymptomatic severe carotid stenosis with diabetes mellitus (DM) are contradictory. To evaluate perioperative and long-term results of CEA in patients with DM, we retrospectively analyzed data of patients with or without DM who underwent CEA in our institute. Between January 2005 and December 2010, 281 consecutive CEAs were performed in 268 patients under general anesthesia. All patients were subject to cardiac work-ups before surgery, and coronary revascularization was performed prior to CEA if patients were diagnosed with significant coronary artery stenosis. Lesion characteristics were assessed by a duplex ultrasound scan, computed tomography angiography (CTA), and plaque imaging on magnetic resonance imaging (MRI) before surgery, and patients were followed-up by a duplex ultrasound scan at three, six, and 12 months, then yearly, after surgery. Of 281 cases, 136 had DM (48 %). Diabetic patients more frequently had a history of coronary artery disease than non-diabetic patients (48.5 % vs. 36.6 %, P = 0.042). Coronary intervention prior to CEA was more frequently performed in diabetic patients than in non-diabetic patients (22.1 % vs. 11.0 %, P = 0.013). The incidence of perioperative (30 day) stroke (P = 1.000), death (P = 1.000), and cardiac complications (P = 0.484) did not differ among groups. Follow-up was available in 77.2 % of patients, with a median duration of 50 months (interquartile range, 32.1-67.2 months). The incidence of ipsilateral stroke (P = 0.720), death (P = 0.351), and severe restenosis (peak systolic velocity > 230 cm/sec) (P = 0.905) were not different between groups. DM does not increase the risk of perioperative complications and does not influence long-term outcomes after CEA if preexisting vascular risk factors and cardiac diseases are appropriately evaluated and treated before surgery.