Background: Apart from advanced age, little is known about predictors of the long-term outcome after carotid artery stenting (CAS).
Objective: We sought to determine whether atherosclerotic risk factors predict the long-term outcome after CAS.
Patients and methods: We enrolled 532 patients assigned for CAS. The primary composite end-point, including stroke, myocardial infarction and all-cause mortality, was observed in 100 patients (19%) during the long-term follow-up (median 28 months, interquartile range 14-49 months).
Results: Cumulative event rates at 1, 3 and 5 years were 4.4%, 17.1% and 33.4%, respectively. High-density lipoprotein (HDL) cholesterol was an independent predictor of event-free survival. The adjusted hazard ratio for the primary end-point was 0.97 per increase of 1 mg dL(-1) HDL cholesterol [95% confidence interval (CI) 0.95-0.99, P = 0.002) and 2.7 (95% CI 1.6-4.4, P < 0.001) for low HDL cholesterol (< 40 mg dL(-1) in men and < 50 mg dL(-1) in women). Inflammatory activation (leukocyte count > 10,000 mL(-1) or fibrinogen > 450 mg dL(-1) or erythrocyte sedimentation rate > 20 mm h(-1)) was the only other independent atherosclerotic risk factor (P = 0.001). Patients with low HDL cholesterol and elevated inflammatory activation were at very high risk, with a 5-year event rate of 59.4% (95% CI 43.6-75.2%) as compared to 15.1% (95% CI 8.2-22.0%) in those without both risk factors (log rank, P < 0.001). Age, occlusion of the contralateral carotid artery and heart failure were further independent risk predictors (P < 0.01 for all).
Conclusions: Low HDL cholesterol is an independent predictor of the long-term outcome after CAS. The combination of low HDL cholesterol and elevated inflammatory markers identified high-risk patients.