Homocysteine Improves Risk Stratification in Patients Undergoing Endarterectomy for Asymptomatic Internal Carotid Artery Stenosis

Abstract

A limited life expectancy reduces the benefit from carotid endarterectomy (CEA) for treatment of asymptomatic internal carotid artery stenosis. The aim of this study was to assess homocysteine as stratifying biomarker to improve prediction of postoperative survival. This was a prospective, nonrandomized case series from 2003 to 2012. Two hundred and fourteen consecutive patients (<75 years, n=130; ≥75 years, n=84) undergoing CEA for their asymptomatic internal carotid artery stenosis were observed for 8.5 years for the occurrence of death after CEA as primary end point (EC-nr: 04-067-0604). Homocysteine and major cardiovascular risk factors were used for computation of prognostic indices. Cumulative survival of prognostic indices-based quintiles was estimated by Kaplan-Meier curves. Total homocysteine had a significant effect on postoperative survival (P<0.0001). Total homocysteine-based quintiles of prognostic indices showed a better prediction of the survival of the patients than age alone. This caused reclassification of 17 patients (20.2%)>75 years as fit for surgery, but also indicated a high risk for 19 patients (14.6%)<75 years. In the majority (79.8%) of patients aged>75 years, statistically, CEA could not be advised because of a significantly reduced 5-year survival rate. High plasma homocysteine levels suggest that older patients with asymptomatic carotid stenosis might rather benefit from intensive medical therapy than from CEA.