Serum osteoprotegerin levels and long-term prognosis in subjects with stable coronary artery disease

Background: Osteoprotegerin (OPG) is a secretory glycoprotein which belongs to the tumor necrosis factor receptor family. OPG immunoreactivity was demonstrated in normal blood vessels and in early atherosclerotic lesions. In a previous study, we showed that high serum OPG levels are associated with progression of coronary artery disease (CAD). Objectives: The present study was designed to assess the association between serum OPG level and long-term prognosis in patients with stable coronary artery disease. Methods: We performed a prospective, observational cohort study in 225 subjects to examine whether serum OPG levels can predict cardiovascular mortality. The median OPG levels were 1.02 ng mL(-1) at baseline. Results: During the follow-up (61 +/- 25 months), 27 deaths occurred including 13 cardiovascular deaths. When the subjects were divided into three groups according to serum OPG level, the group with high serum OPG showed a higher risk for cardiovascular mortality. A Multivariate Cox proportional hazards model indicated that the higher risk of cardiovascular death in the high OPG level group remained significant (hazards ratio of 7.44, 95% CI 0.92-60.30, highest vs. lowest OPG tertile). In contrast, serum OPG levels were not associated with non-cardiovascular mortality. Conclusions: Our data show that serum OPG levels are an independent predictor of cardiovascular mortality in patients with stable coronary artery disease.