Serum osteoprotegerin and carotid intima-media thickness in acute/chronic coronary artery diseases

Aims Osteoprotegerin (OPG) plays a key role in atherosclerosis progression and plaque destabilization. We investigated the relationship between intima-media thickness of the common carotid artery (CCA-IMT; an early marker of atherosclerosis) and OPG levels in patients with acute coronary syndrome (ACS) and chronic coronary artery disease (CAD). Methods We studied 133 consecutive patients, mean age 65+/-9 years, referred to our department for coronary angiography. They were evaluated for cardiovascular risk factors, OPG levels and CCA-IMT and accordingly divided in two subgroups: ACS and chronic CAD. Results Except for age, the two groups were similar according to conventional cardiovascular risk factors. The chronic CAD group showed a CCA-IMT lower than the ACS group (0.86+/-0.15 vs. 0.94+/-0.22 mm, P=0.027); there were no differences regarding the extension of coronary atherosclerosis on angiograms. The OPG levels were higher in chronic CAD patients than in ACS patients (5.36+/-3.06 vs. 3.85+/-2.96 pmol/l, P=0.004). Moreover, the CCA-IMT was significantly correlated with the age of the patients (r=0.5; P<0.001). OPG values were not related either to age or to the CCA-IMT. At analysis of covariance, when adjusting the groups for age, the comparison of the two groups lost statistical significance for CCA-IMT (P=0.41), whereas the OPG values remained significant after the correction (P=0.001). Conclusion OPG levels are higher in chronic CAD patients. CCA-IMT confirmed its importance in predicting CAD, showing significantly higher values in the patients in the ACS group as compared with those in the chronic CAD group.