Serum levels of γ-glutamyltransferase and progression of coronary atherosclerosis

Abstract

Progression of coronary atherosclerosis (ATS) has clinical implications. Serum levels of γ-glutamyltransferase (GGT), a marker of oxidative stress, predict the risk of cardiovascular events. However, the role of GGT levels in the progression of coronary ATS has never been established. Consecutive patients undergoing two coronary angiographies (CAs) separated by at least 6 months were prospectively enrolled between May 2008 and June 2010. All patients were discharged on statins after the first CA. The severity and extent of coronary ATS were graded according to Bogaty's score, and the variation (Δ) in stenosis score and extent index between follow-up (S2 and E2) and basal values (S1 and E1) were calculated. Predictors of ΔS2-1 and ΔE2-1 were assessed among clinical and laboratory data, including GGT levels, analyzed as Δ between follow-up and basal values (ΔGGT2-1). We enrolled 100 consecutive patients (age 64±11 years, 68% men). Compliance with statin therapy was 100%. At multiple regression analysis, ΔGGT2-1 was the only independent predictor of ΔS2-1 (B=0.18, SE=0.07, P=0.05), with Δlow-density lipoprotein-cholesterol2-1 levels being of borderline statistical significance (P=0.07). On multiple regression analysis, ΔGGT2-1 was the only independent predictor of ΔE2-1 (B=0.32; SE=0.11; P=0.04), with active smoking habit and Δfibrinogen2-1 levels being of borderline statistical significance (P=0.08 and 0.06, respectively). ΔGGT2-1 is associated with angiographic coronary ATS progression in patients with ischemic heart disease on statin treatment, suggesting that oxidative stress may be another therapeutic target for preventing ATS progression beyond that of lipid-lowering therapies.