Jennifer Beede

Serial Sampling of ST2 Predicts 90-Day Mortality Following Destabilized Heart Failure

BACKGROUND To prospectively determine the prognostic utility of serial sampling of the interleukin-1 receptor family member, ST2, for predicting 90-day mortality in patients with heart failure (HF) admitted to a Veteran Affairs Medical Center. METHODS AND RESULTS A total 150 patients hospitalized with acutely destabilized HF were followed at the Veteran Affairs Healthcare System in San Diego, CA. Multiple cardiac-related parameters were measured including ST2, B-type natriuretic peptide (BNP), NT-proBNP, and blood urea nitrogen (BUN). Plasma samples were collected at 6 time points between admission and discharge. Biomarker concentrations were correlated to survival at 90 days. Uni- and multivariate analyses were used to identify prognostic variables. From admission to discharge, percent change in ST2 was strongly predictive of 90-day mortality: those patients whose ST2 values decreased by 15.5% or more during the study period had a 7% chance of death, whereas patients whose ST2 levels failed to decrease by 15.5% in this time interval had a 33% chance of dying. CONCLUSIONS Percent change in ST2 concentrations during acute HF treatment is predictive of 90-day mortality and was independent of BNP or NT-proBNP levels. ST2 may provide clinicians with an additional tool for guiding treatment in patients with acute destabilized HF.

Pro-B-Type Natriuretic Peptide Levels in Acute Decompensated Heart Failure

OBJECTIVES The present study sought to evaluate the clinical utility of pro-B-type natriuretic peptides (proBNP) in patients admitted with acute decompensated heart failure. BACKGROUND Plasma natriuretic peptides (BNP(1-)(32), N-terminal [NT]-proBNP(1-76)) have been demonstrated to assist in the diagnosis of patients with heart failure. However, the precursor to these polypeptides (proBNP(1-108)) circulates in plasma and may interfere with the measurement of currently used biomarkers. METHODS Plasma natriuretic peptides were assessed in 164 individuals (99% men) hospitalized with decompensated heart failure. The B-type natriuretic peptide (BNP), NT-proBNP, and proBNP levels at hospital admission and discharge were compared with the incidence of cardiac death and all-cause mortality within 90 days post-discharge. RESULTS Pro-B-type natriuretic peptides demonstrated a high degree of correlation with both BNP (R = 0.924, p < 0.001) and NT-proBNP (R = 0.802, p < 0.001) at admission. Further characterization of proBNP demonstrated little variation with changes in age, body mass index, creatinine, or systolic dysfunction. All 3 plasma natriuretic peptides were significantly elevated at admission in patients suffering a cardiac death or all-cause mortality (p < 0.05). Receiver-operating characteristic curves demonstrated that admission and discharge NT-proBNP (area under the curve [AUC] 0.788 and AUC 0.834) had superior prognostic power for all-cause mortality when compared with BNP (AUC 0.644, p < 0.01 and AUC 0.709, p < 0.01) and proBNP (AUC 0.653, p < 0.01 and AUC 0.666, p < 0.01) at the same time points. CONCLUSIONS Admission values of all natriuretic peptides can be used to predict cardiac death and all-cause mortality. A preliminary comparison suggests that discharge values of NT-proBNP have the greatest diagnostic yield for predicting these end points. Further studies should explore the synergistic prognostic potential of all natriuretic peptides.

Correlation and Prognostic Utility of B-Type Natriuretic Peptide and Its Amino-Terminal Fragment in Patients With Chronic Kidney Disease

This study compared the correlation and prognostic utility of B-type natriuretic peptide (BNP) and the N-terminal fragment of proBNP (NT-proBNP) in 171 outpatients with renal dysfunction. The NT-proBNP correlated well with BNP in all cases (r = 0.911; P pound .01), regardless of degree of renal impairment or type of left ventricular dysfunction. BNP and NT-proBNP concentrations (P < .005) and their ratios (P pound .01) increased as the glomerular filtration rate (GFR) declined, indicating a greater effect of GFR on NT-proBNP levels. Both natriuretic peptide levels were higher in patients with systolic dysfunction (P < .05) compared with patients with normal echocardiograms. In contrast, BNP and NT-proBNP levels were below the diagnostic cutoffs for congestive heart failure exacerbations in patients with normal heart function or diastolic dysfunction, with no statistical difference between these groups (P = .99). Both peptides are useful prognostic tools for predicting mortality and cardiac hospitalization in renal patients.