Diabetes mellitus as a risk factor for early outcome after carotid endarterectomy - A population-based study

Abstract

Background and purpose: to determine if diabetes mellitus is a risk factor for outcome after carotid endarterectomy (CEA). Methods: the outcome and complications of all vascular procedures performed in Sweden are registered prospectively in the Swedish Vascular Registry (Swedvasc) and form the basis of this report. During the 10-year period 1987-96 2622 CEAs were analysed for notified complications. Results: of the 2622 CEAs, 341 (13%) were performed on diabetics and 2281 (87%) on non-diabetics. Patients with diabetes presented at a younger age (67.1 ± 8.3 years vs. 68.2 ± 8.3 years; p = 0.028), were more likely to have a history of hypertension (61.9% vs. 50%; p = 0.001) and were less often smokers (34.9% vs. 43.2%; p = 0.001). Diabetics presented more often with minor stroke (41.3% vs. 30.8%; p = 0.002) and non-diabetics more often with amaurosis fugax (18.9% vs. 14.4%; p = 0.04). Diabetics had a higher 30-day mortality (3.2% vs. 1.4%; p = 0.02). The 30-day neurologic and cardiac morbidity did not differ. The 1-year mortality was 7.9% in diabetics and 4.4% in non-diabetics (p = 0.008). Non-diabetics operated on in 1992-96 compared to those operated on in 1987-91 had a significantly lower combined permanent stroke and death rate (3.7% vs. 5.7%; p = 0.05), a diffeence not found in diabetics (6.3% for 1987-92 and 6.8% for 1992-96; N.S.). Conclusions: diabetics had both a higher 30-day and 1-year mortality after CEA compared to non-diabetics, mainly because of cardiac complication. However, postoperative neurologic morbidity did not differ.