Metabolic syndrome: A predictor of adverse outcomes after carotid revascularization

Metabolic syndrome (MetS) is rapidly increasing in prevalence and is associated with carotid plaque development and is a risk factor for stroke. The aim of this study is to describe the outcomes for patients with MetS after carotid revascularization (carotid endarterectomy [CEA] and carotid stenting [CAS]).

A database of patients undergoing carotid revascularization for primary atherosclerotic lesions was queried from 1996 to 2006. MetS was defined as the presence of >or=3 of the following criteria: blood pressure >or=130 mm Hg/>or=90 mm Hg; Triglycerides >or=150 mg/dL; high-density lipoproteins (HDL) or=110 mg/dL; or Body Mass Index (BMI) >or=30 kg/m(2). Multivariate and Kaplan-Meier analyses were performed to outcomes. The average follow-up period was 4.5 years. A major adverse event (MAE) was defined as the occurrence of stroke, myocardial infarction (MI), or death.

A total of 921 patients (mean age: 71 +/- 10 years; 64% male) underwent 750 CEAs and 171 CAS. Thirty-one percent were identified as having MetS, 48% were asymptomatic, 87% had hypertension, 27% had hyperlipidemia, 32% were considered diabetic, and 14% had chronic renal insufficiency. The morbidity and mortality rates for all patients were 16.9% and 1.1%, respectively. The 30-day combined stroke/death rate was 3.6%. The 30-day MAE rates were: 6.7% vs 3.3% for MetS vs No-MetS (P = .02). The 90-day MAE rates were 8.7% vs 4.9% for MetS vs No-MetS (P = .03). MetS patients were more likely to experience a complication than No-MetS patients (23% vs 14%, P = .001). By Kaplan-Meier analysis, there was no difference between MetS and No-MetS patients with respect to patency, restenosis, re-intervention, or survival, but a difference existed for freedom from stroke, MI, and MAE. The difference between stroke rates was maintained between MetS and No-MetS, when subgrouped by those with and without symptoms. For patients with diabetes mellitus (DM), those with MetS had a 68% and 410% higher risk of developing an MAE and MI, respectively. However, for patients without diabetes, MetS was not significantly associated with MAE, stroke, or MI. No factors were found to be significantly associated with risk of stroke in all cases (in all patients, patients with diabetes, and patients without diabetes).

MetS is prevalent among patients undergoing carotid revascularization. MetS patients are at a greater risk for perioperative morbidity as well as stroke, MI, and MAE during follow-up when compared to patients without MetS. Long-term stroke prevention is poor in the presence of MetS. MetS should be considered a significant risk factor for patients undergoing carotid revascularization.