Oxidative stress and severity of coronary artery disease in patients with acute coronary syndrome

Aims Oxidative stress is associated with atherosclerosis and plaque lesions in experimental in vitro models. Few in vivo studies have examined the association between redox status and the prognosis of acute coronary syndromes. We aimed to investigate the relation between the oxidative stress and coronary artery disease (CAD) severity in patients presenting with acute coronary syndromes. Methods and Results We undertook a prospective, observational study of 117 patients who had been admitted because of an acute coronary syndrome. We recorded clinical and angiographic features and cardio-vascular events (cardio-vascular death, reinfarction, readmission with a new ischemic event, or need for coronary revascularization). Oxidative stress indices including glutathione peroxidase (GPX) and superoxide dismutase (SOD) activities were measured in serum(markers of systemic antioxidant status). The mean age of the patients (86% of whom were men) was 61.5 ± 11.7 years; 57.3% were admitted with non-ST-segment-elevation acute coronary syndrome. Left ventricular ejection fraction was normal (> 50%) in 53.4%. Both SOD and GPX were associated with the severity of coronary artery disease (CAD). SOD and GPX levels were significantly lower in patients with 3-vessels disease P = 0.001 and P = 0.017 respectively). SOD and GPX activities were correlated with the SYNTAX score (y = 1.3 ± 0,01, R2= 0.01). Mean duration of the follow-up period was 6.9 ± 2.05 months. In the 15.15% who experienced cardio-vascular events, SOD and GPX activities were lower, without statistical correlation (P = 0.56, P = 0.23). Conclusion Oxidative stress is an important contributor to CAD. A low level of activities of SOD and GPX is independently associated with the severity of coronary artery disease in patients presenting an acute coronary syndrome.