Osteoprotegrin may be biomarker of cardiovascular mortality
MedWire News: The biomarker osteoprotegrin (OPG) is independently associated with adverse outcomes at 30 days and 1 year in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS), research shows.
"As no independent relationship between OPG levels and recurrent ischemia or myocardial infarction (MI) was observed, myocardial dysfunction may be a more important stimulus for OPG production than ischemia in ACS," say Torbjørn Omland (Akershus University Hospital, Løenskog, Norway) and co-authors.
They assessed whether OPG, a member of the tumor necrosis factor receptor superfamily, is a biomarker of cardiovascular (CV) mortality in 4463 patients with NSTE-ACS from the Metabolic Efficacy with Ranolazine for Less Ischemia in NSTE-ACS (MERLIN)-Thrombolysis in Myocardial Infarction (TIMI) trial.
During a median follow-up period of 341 days, 208 patients died of CV causes. The researchers found that baseline OPG (median 1632 ng/L with cut-off levels between tertiles of 1345 ng/L and 2000 ng/L, respectively) was significantly associated with CV mortality at 30 days and 1 year.
After adjustment for conventional risk markers including TIMI risk score covariates, log transformed baseline OPG concentration was a significant predictor for CV mortality at 30 days (hazard ratio [HR]=2.32 for each standard deviation [SD] increase) and at 1 year (HR=1.85 for each SD increase ).
Comparing the third versus the first and second tertiles yielded an adjusted HR of 2.14 for CV mortality at 30 days and 1.78 at 1 year (p<0.009).
Log transformed baseline OPG was also significantly associated with new or worsening HF at 30 days (HR=2.25 per SD increase) and at 1 year (HR=1.81 per SD increase, both p=0.001).
Further analysis revealed that although baseline OPG was significantly associated with recurrent MI within 12 months, this association was attenuated and no longer significant after multivariate adjustment.
"These findings suggest that left ventricular dysfunction, rather than myocardial ischemia, is the more important mediator of the adverse prognosis indicated by elevation of OPG in ACS," comment the researchers in Heart.
"Our findings in this well characterized patient population add to the emerging evidence supporting involvement of OPG in the pathophysiology of ACS and its consequences, and support investigation of therapies that might modify this risk, including the elucidation of OPG related pathways that might be evaluated as targets for intervention," they conclude.
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By Piriya Mahendra