B-type natriuretic peptide. Guided vs. conventional care in outpatients with chronic heart failure: a retrospective study

Abstract

Aim: It is not known whether therapy assisted by determinations of serum B-type natriuretic peptide (BNP) may improve the outcome for outpatients with chronic heart failure (CHF).

Methods: A retrospective case-control study was carried out, enrolling patients with acutely decompensated heart failure (ADHF) who were followed up for a mean period of four months. The patients who had died or had new episodes of ADHF were studied as the cases. For each case, one living patient who was free from ADHF-related re-hospitalisations was recruited as control. Cases and controls were also matched for some variables to minimise possible confounding. The possible role of BNP-guided therapy as a predictor of decreased risk of deaths or new hospitalisations related to heart failure was explored.

Results: Twenty-eight cases and 44 controls were enrolled. A fall in BNP on the fifth day after admission was found to be a predictor of a decreased risk of the composite endpoint "death or new hospitalisation, heart failure-related" (hazard ratio=0.1508; 95% CI: 0.049 to 0.463; P=0.001). On the other hand, low glomerular filtration rate at admission (<60 mL/min/1.73 m2) was associated with increased risk of the abovementioned endpoint (hazard ratio=7.1785; 95% CI: 1.574 to 32.725; P=0.0113). On the contrary, BNP-guided therapy was associated with a similar risk of death and/or CHF-related hospitalisation, compared to the conventional clinical approach.

Conclusion: A fall in BNP ≥60% from baseline on the fifth day after admission was found to be associated with a favorable clinical outcome in outpatients with CHF after four months of follow-up, irrespective whether this finding had been detected in patients treated according to the BNP-guided therapy or in patients treated with conventional clinical criteria. However, among the outpatients with previous ADHF, a substantial improvement in cardiovascular event rates could not be demonstrated in those treated with BNP-guided therapy compared with those undergoing usual, symptom-guided treatment.