Risk of insulin-dependent diabetes mellitus in patients undergoing carotid endarterectomy

Abstract

Objective: There is conflicting evidence regarding the association of diabetes mellitus (DM) and insulin use with outcomes after carotid endarterectomy (CEA). Therefore, we sought to evaluate the risk of insulin-dependent DM (IDDM) and noninsulin-dependent DM (NIDDM) on 30-day outcomes after CEA.

Methods: We identified patients undergoing CEA from the Targeted Vascular module of the National Surgical Quality Improvement Program (2011-2015) and stratified patients on the basis of their preprocedural symptom status. We compared 30-day outcomes between nondiabetics and patients with NIDDM or IDDM, with 30-day stroke/death as the primary end point.

Results: Of 16,739 CEA patients, 9784 (58%) were asymptomatic, of whom 6720 (69%) had no diagnosis of DM, 1109 (11%) had IDDM, and 1955 (20%) had NIDDM. Of the 6955 symptomatic patients, 4982 (72%) had no diagnosis of DM, 810 (12%) had IDDM, and 1163 (17%) had NIDDM. Among asymptomatic patients, patients with IDDM experienced higher rates of 30-day stroke/death compared with those without DM (3.4% vs 1.5%; P < .001), whereas those with NIDDM experienced rates similar to those of patients without DM (2.1% vs 1.5%; P = .1). Moreover, asymptomatic patients with IDDM and an anatomic high-risk criterion experienced a 30-day stroke/death rate of 6.6%. After adjustment, IDDM was associated with 30-day stroke/death in asymptomatic patients compared with patients without DM (odds ratio, 2.3; 95% confidence interval, 1.5-3.4; P < .001), but NIDDM was not (odds ratio, 1.4; 95% confidence interval, 1.0-2.1; P = .1). In comparison, among symptomatic patients, those with IDDM and NIDDM experienced similar rates of 30-day stroke/death as patients without DM (4.9% vs 3.6% and 4.0% vs 3.6%; both P > .1). After adjustment, neither IDDM nor NIDDM was associated with 30-day stroke/death in symptomatic patients compared with symptomatic patients without DM.

Conclusions: Rates of 30-day stroke/death after CEA in asymptomatic patients with IDDM exceed international vascular societies' guideline thresholds for acceptable outcomes in asymptomatic patients, especially those with anatomic high-risk criteria. Thus, asymptomatic patients with IDDM may not benefit from CEA, although more data are needed about the natural history of carotid disease in this population.

Keywords: Carotid endarterectomy; Diabetes mellitus; Insulin use.