Cardiac Biomarker Assesses Heart Failure Prognosis

An assay to measure the amount of soluble growth stimulation expressed gene 2 protein (ST2) has been used to identify heart failure patients who are significantly more likely to have a heart transplant or to die during the three-year follow-up period.

In a multicenter cohort study, 1,141 heart failure patients were recruited from three tertiary-care centers, and were followed for a median of 2.8 years. ST2 levels were measured at baseline from a blood sample taken at the enrollment of each patient into the study. The investigators conducted statistical analyses to predict outcomes by examining clinical presentation as well as the cardiac biomarkers ST2 and N-terminal brain natriuretic peptide (NT-proBNP).

The test used was the Presage ST2 Assay (Critical Diagnostics, San Diego, CA, USA). There were 267 (23% of patients) adverse events over the period, defined as the combined endpoint of death or cardiac transplantation. Patients in the highest ST2 tertile with levels above 36.3 ng/mL, had a markedly increased risk of adverse outcomes compared to the lowest tertile whose ST2 levels were equal to or less than 22.3 ng/mL. The unadjusted hazard ratio (HR) of 3.2 remained significant after multivariable adjustment; adjusted HR equaled 1.9. With each doubling of ST2, there was a 40% to 50% increased risk of death or cardiac transplantation in fully adjusted models.

Soluble ST2 reflects activity of an interleukin (IL-33) dependent cardioprotective signaling axis and is a diagnostic and prognostic marker in acute heart failure. ST2 signals the presence of adverse cardiac remodeling and fibrosis, which occurs in response to myocardial infarction (MI), ischemia, or worsening heart failure. Remodeling and fibrosis can also contribute to the development of future adverse events, such as secondary MI or sudden cardiac death, and to progression of heart failure.

Patrick A. Arensdorf, B.A., M.B.A., CEO of Critical Diagnostics, said, "The study found that more than one in seven chronic heart failure patients can be more appropriately risk-stratified when using ST2 and NT-proBNP in addition to the Seattle Heart Failure Model. By using the Presage ST2 Assay, clinicians may be able to target heart failure therapy more appropriately.” The study was published as an advance e-publication of the January 19, 2010 edition of Circulation: Heart Failure.

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