Time-Dependent Changes in N-Terminal Pro-Brain Natriuretic Peptide and B-Type Natriuretic Peptide Ratio During Hospitalization for Acute Heart Failure

Abstract

The time-dependent changes in the simultaneous evaluation of B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) levels during hospitalization for acute heart failure (AHF) remain obscure. A total of 356 AHF patients were analyzed. Blood samples were collected within 15 minutes of admission (Day 1), 48-120 hours (Day 2-5) and between days 7 and 21 (Before-discharge). Plasma BNP and serum NT-proBNP were significantly decreased on Days 2-5 and Before-discharge in comparison to Day 1, but the NT-proBNP/BNP ratio was not changed. Patients were divided into 2 groups according to the median NT-proBNP/ BNP (N/B) ratio on Day 2-5 (Low-N/B versus High-N/B). A multivariate logistic regression model showed that age (per 1-year increase), serum creatinine (per 1.0-mg/dL increase), and serum albumin (per 1.0-mg/dL de-crease) were independently associated with High-N/B (odds ratio [OR]: 1.071, 95%confidence interval [CI]: 1.036-1.108, OR: 1.190, 95%CI: 1.121-1.264 and OR: 2.410, 95%CI: 1.121-5.155, respectively). Kaplan-Meier curve analysis showed that the High-N/B group had a significantly poorer prognosis than the Low-N/B group, and a multivariate Cox regression model revealed that High-N/B was an independent predictor of 365-day mortality (hazard ratio [HR]: 1.796, 95%CI: 1.041-3.100) and HF events (HR: 1.509, 95%CI: 1.007-2.263). The same trend in prognostic impact was significantly observed in both low and high delta-BNP cohorts (< 55% and ≥55% BNP value on the start date/BNP value at 2-5-days). A high NT-proBNP/BNP ratio on Day 2-5 was associated with non-cardiac conditions and was associated with adverse outcomes even if BNP was adequately decreased by the treatment of AHF.