Patients with diabetes differ in atherosclerotic plaque characteristics and have worse clinical outcome after iliofemoral endarterectomy compared with patients without diabetes

Objective Diabetes mellitus (DM) is associated with peripheral arterial disease (PAD) and leads to worse clinical outcome compared with patients without DM. The objective of this study was to determine the impact of DM on iliofemoral artery plaque characteristics and to examine secondary clinical outcomes in patients with DM and PAD undergoing surgical revascularization. Methods We analyzed 198 patients with and 453 patients without DM from the Athero-Express biobank, a prospective ongoing biobank study, who underwent endarterectomy of the femoral or iliac artery between 2002 and 2013. Seven histologic plaque characteristics (calcification, collagen, lipid core, intraplaque hemorrhage, macrophages, microvessels, and smooth muscle cells) and secondary clinical outcome were compared. Composite outcome consisted of any of the following secondary manifestations of cardiovascular disease: stroke, myocardial infarction, cardiovascular death, or peripheral intervention. In addition, target vessel revascularization (TVR) was examined. The follow-up period was standardized at 3 years after the procedure. Results Patients with DM were more likely to have calcified plaques compared with patients without DM (odds ratio, 2.11; 95% confidence interval, 1.43-3.12; P < .01). No other plaque characteristic differed significantly between the two groups. In total, 112 (57.1%) patients with DM and 198 (45.1%) patients without DM reached a composite end point during follow-up, of whom 21 (10.7%) and 27 (6.2%) died of cardiovascular causes, respectively. DM was an independent predictor of composite cardiovascular events (hazard ratio, 1.36; 95% confidence interval, 1.020-1.801; P = .01) during follow-up. No difference in the incidence of TVR was observed between patients with and without DM (31.5% and 30%, respectively; difference in survival time, P = .86) or in longer duration of DM with composite event-free survival (difference in survival time, P = .57). Conclusions Patients with DM who undergo surgical revascularization for PAD with the use of thromboendarterectomy or remote endarterectomy have a more calcified atherosclerotic plaque and an increased incidence in composite cardiovascular events but no increase in TVR.