Change of Serum BNP Between Admission and Discharge After Acute Decompensated Heart Failure Is a Better Predictor of 6-Month All-Cause Mortality Than the Single BNP Value Determined at Admission

BACKGROUND: B-type natriuretic peptide (BNP) is regarded as a reliable predictor of outcome in patients with acute decompensated heart failure (ADHF). However, according to some scholars, a single isolated measurement of serum BNP at the time of hospital admission would not be sufficient to provide reliable prognostic information. METHODS: A retrospective study was carried out on patients hospitalized for ADHF, who had then undergone follow-up of at least 6 months, in order to see if there was any difference in midterm mortality among patients with rising BNP at discharge as compared to those with decreasing BNP at discharge. Medical records had to be carefully examined to divide the case records into two groups, the former characterized by an increase in BNP during hospitalization, and the latter showing a decrease in BNP from the time of admission to the time of discharge. RESULTS: Ultimately, 177 patients were enrolled in a retrospective study. Among them, 53 patients (29.94%) had increased BNPs at the time of discharge relative to admission, whereas 124 (70.06%) exhibited decreases in serum BNP during their hospital stay. The group with patients who exhibited BNP increases at the time of discharge had higher degree of congestion evident in the higher frequency of persistent jugular venous distention (odds ratio: 3.72; P = 0.0001) and persistent orthopnea at discharge (odds ratio: 2.93; P = 0.0016). Moreover, patients with increased BNP at the time of discharge had a lower reduction in inferior vena cava maximum diameter (1.58 ± 2.2 mm vs. 6.32 ± 1.82 mm; P = 0.001 (one-way ANOVA)). In contrast, there was no significant difference in weight loss when patients with increased BNP at discharge were compared to those with no such increase. A total of 14 patients (7.9%) died during the 6-month follow-up period. Cox proportional hazard analysis revealed that BNP increase at the time of discharge was an independent predictor of 6-month all-cause mortality after adjustment for age, sodium at discharge, creatinine at discharge and New York Heart Association (NYHA) class at discharge (hazard ratio 34.49; 95% confidence intervals: 4.55 - 261.06; P = 0.001). CONCLUSIONS: Among patients with recent ADHF, increased BNP at the time of discharge from the hospital entailed a higher grade of congestion and higher 6-month mortality.