Osteoprotegerin in ST-elevation myocardial infarction: Prognostic impact and association with markers of myocardial damage by magnetic resonance imaging

Background/Objectives: For osteoprotegerin (OPG), a cytokine of the tumor necrosis factor superfamily, the prognostic impact in stable coronary artery disease and acute coronary syndromes has been shown recently. In acute ST-elevation myocardial infarction (STEMI) data on the correlation to myocardial damage by cardiac magnetic resonance imaging (CMR) or clinical outcome are lacking. Methods: We studied 221 consecutive patients with acute STEMI undergoing primary percutaneous coronary intervention (PCI) within 12 h after symptom onset. Serum levels of OPG were determined from samples collected before PCI (OPG0), at 24 (OPG1) and 48 h (OPG2) after reperfusion. CMR studies for assessment of infarct size, reperfusion injury/microvascular obstruction and myocardial salvage were performed within one week after infarction. Long-term clinical follow-up for major adverse cardiovascular events (MACE), defined as death, myocardial infarction, or new onset of congestive heart failure, was performed 18.2 (interquartile range of 9.2-21.2) months after the index event. Results: OPG levels ≥ 75th percentile were associated with significantly larger infarcts, lower myocardial salvage index and greater extent of microvascular obstruction in CMR as compared to OPG levels < 75th percentile. The MACE rate for patients with OPG levels in the highest quartile was also significantly higher. In a multivariable model adjusted for known risk factors, OPG1 as a continuous variable was independently predictive for MACE. Conclusion: OPG serum levels collected 24 h after infarction are independent predictors of MACE in acute STEMI patients. High OPG levels are associated with a greater extent of myocardial damage and lower myocardial salvage by CMR.