Role of preprocedural glutathione concentrations in the prediction of major adverse cardiac events in patients with acute coronary syndrome treated with percutaneous coronary intervention

INTRODUCTION Poor antioxidant protection of cardiomyocytes due to cardiac ischemia and low serum levels of reduced glutathione (GSH) may be associated with enhanced risk of coronary restenosis after primary percutaneous coronary intervention (pPCI). 
OBJECTIVES The aim of this study was to investigate whether preprocedural serum reduced GSH, reflecting the antioxidant status, may be predictive of major adverse cardiac events (MACE) in patients with acute coronary syndrome (ACS) treated with pPCI. 
PATIENTS AND METHODS Preprocedural serum GSH level was evaluated in 141 patients with ACS treated with pPCI with bare‑metal stent (BMS) deployment. During a 15‑month follow‑up, 30 patients (mean age, 61 ±10 years) experienced a MACE. The remaining 111 subjects constituted the non‑MACE group (mean age, 63 ±10 years). 
RESULTS The MACE group had significantly lower GSH levels compared with the non‑MACE group (P <0.001); significant differences were also observed in a subgroup of type 2 diabetic patients (P <0.001). All patients were arbitrarily classified as having low (median, ≤1.39; 1.04–1.55 μmol/l) or high serum GSH (median, >2.26; 2.09–2.99 μmol/l; P <0.001). The Kaplan–Meier analysis showed a significantly longer MACE‑free survival in patients with higher serum GSH (P <0.004). The Cox proportional hazards regression indicated that patients with lower GSH were 2.2 times more likely to experience MACE (95% confidence interval [CI], 1.2–3.9; P <0.02 for the whole group and 1.8–11.8 for diabetic patients; P <0.002). 
CONCLUSIONS Preprocedural GSH levels may be useful in the prediction of MACE in patients with ACS scheduled for pPCI and BMS deployment, especially in diabetic subjects.