Initially elevated osteoprotegerin serum levels may predict a perioperative myocardial lesion in patients undergoing coronary artery bypass grafting

OBJECTIVE: We investigated whether osteoprotegerin (OPG), an important regulator in the genesis of arteriosclerosis and bone formation, is able to identify patients at risk for perioperative myocardial infarction measured as cardiac troponin I (cTNI) and signs of myocardial ischemia in the electrocardiogram after coronary artery bypass grafting (CABG). DESIGN: Observational study. SETTING: Post-surgical intensive care unit of a tertiary care center. PATIENTS: Ninety-seven patients undergoing elective CABG. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: OPG and cTNI were measured before and 24 hrs after CABG. Additionally, cTNI was measured after 12 hrs. Electrocardiography was done before and immediately after CABG. OPG before CABG (OPGpre) measurements correlated with cTNI measurements after 12 hrs (cTNI12) (r = 0.56; p < .0001) and with cTNI measurements after 24 hrs (cTNI24) (r = 0.77; p < .0001). OPGpre measurements correlated with electrocardiographic findings after surgery (r = 0.65; p < .0001). There was a positive correlation between OPGpre value and the number of bypasses (r = 0.95; p < .0001). A strong correlation was found between OPGpre and homocysteine (r = 0.96; p < .0001). The median OPG presurgical level for the four patients with cardiac complications was found to be notably elevated (28.1 [26.6/31.0] pmol/L) in comparison with that for patients without complications (10.2 [3.7/16.9] pmol/L). CONCLUSIONS: OPG appears to be a useful marker for estimating risk for perioperative myocardial infarction in patients undergoing CABG, as demonstrated by signs of ischemia on electrocardiography.