Diagnostic and prognostic value of urine NT‐proBNP levels in heart failure patients

Abstract

Background: Plasma NT-proBNP levels are sensitive markers of ventricular dysfunction. However, studies of natriuretic peptides in urine are limited. Aims: To compare urine and plasma NT-proBNP levels and to investigate the diagnostic and prognostic value of urine levels in heart failure (HF). Methods: Urinary and plasma NT-proBNP levels were measured in 96 HF patients and 20 control subjects. The patients were functionally classified according to the NYHA criteria. Results: Urine NT-proBNP was higher in HF patients than in control subjects (94 T 31 pg/ml vs. 67 T 6 pg/ml, p < 0.0001), correlating with plasma NT-proBNP levels (r = 0.78, p < 0.0001). Urinary levels were elevated in the more severe functional classes and diminished in obese patients. Urine NT-proBNP was a good tool for diagnosis of HF, the area under the curve (AUC) being 0.96 T 0.02 ( p < 0.0001), and for predicting 12-month cardiac events ( p = 0.011). To determine the prognostic power of urinary NT-proBNP in detecting 12-month cardiac mortality, we obtained an AUC of 0.75 T 0.10 ( p = 0.015). Conclusion: Urinary NT-proBNP, a relatively simple non-invasive test, is a new candidate marker for the diagnosis and evaluation of prognosis in HF and for the characterization of functional status in these patients.

Characterization of NT-proBNP in Human Urine

“…Our data indicate that immunoreactive NT-proBNP is present in human urine as multiple fragments of the 76 -amino acid peptide. We confirmed previous work showing that urine NT-proBNP immunoreactivity correlates with concurrent plasma concentrations (11,12,16 ) in patients with heart failure, is significantly increased in patients with heart failure compared with healthy controls (11,12,15,16 ), and correlates inversely with left ventricular ejection fraction (13 ) and creatinine clearance (12 ).…”

“…Analysis of patients with documented heart failure and healthy controls confirmed that urine NT-proBNP concentrations are increased in heart failure (11,12,15,16 ). The inverse relationship between urine NT-proBNP and left ventricular ejection fraction, together with correlations between plasma and urine concentrations in heart failure, suggests that urine NT-proBNP immunoreactivity is a potential biomarker in heart failure, as previously suggested (11)(12)(13)(14)(15)(16)(17).…”

“…The inverse relationship between urine NT-proBNP and left ventricular ejection fraction, together with correlations between plasma and urine concentrations in heart failure, suggests that urine NT-proBNP immunoreactivity is a potential biomarker in heart failure, as previously suggested (11)(12)(13)(14)(15)(16)(17). Urine concentrations may reflect severity of cardiac decompensation.…”

“…Urine NT-proBNP immunoreactivity has been determined in physiological studies (9,10 ), in heart failure (11)(12)(13)(14), for screening of left ventricular dysfunction in the community (15 ), and for prediction of cardiovascular events in heart failure (16 ). These studies and an editorial (17 ) suggest that urine NT-proBNP represents an alternative to plasma NT-proBNP as a clinical biomarker.…”

Effects of Body Mass Index and Age on N-Terminal Pro–Brain Natriuretic Peptide Are Associated with Glomerular Filtration Rate in Chronic Heart Failure Patients

“…Renal clearance of NT-proBNP is also supported by the extremely high concentrations of NTproBNP in hemodialysis patients (8 ), although this finding may be explained, in part, by accompanying cardiovascular disease (9 ). Renal clearance is further supported by the fact that NT-proBNP can be detected in urine (10 ), although the possibility that some local production occurs within the kidneys cannot be entirely excluded (11 ).…”