Challenging the two concepts in determining the appropriate pre-discharge N-terminal pro-brain natriuretic peptide treatment target in acute decompensated heart failure patients: absolute or relative discharge levels?

Abstract

Aims: NT-proBNP is a strong predictor for readmissions and mortality in acute decompensated heart failure (ADHF) patients. We assessed whether absolute or relative NT-proBNP levels should be used as pre discharge treatment target.

Methods and results: Our study population was assembled from seven ADHF cohorts. We defined absolute (<1500, <3000, <5000, and <15 000 ng/L) and relative NT-proBNP targets (>30, >50, and >70%). Population attributable risk fraction (PARF) is the proportion of all-cause 6-month mortality in the population that would be reduced if all patients attain the NT-proBNP target. PARF was determined for each target as well as the percentage of patients attaining the NT-proBNP target. Attainability was investigated by logistic regression analysis. A total of 1266 patients [age 74 (64-80), 60% male] was studied. For every absolute NT-proBNP level, a corresponding percentage reduction was found that resulted in similar PARFs. The highest PARF (∼60-70%) was observed for <1500 or >70%, but attainability was low (27% and 22%, respectively). The strongest predictor for not attaining these targets was admission NT-proBNP. In admission NT-proBNP tertiles, PARFs were significantly different for absolute, but not for relative targets.

Conclusion: In an ADHF population, pre-discharge absolute or relative NT-proBNP targets may both be useful as they have similar effects on PARF. However, depending on admission NT-proBNP, absolute targets show varying PARFs, while PARFs for relative targets were similar. A relative target is predicted to reduce mortality consistently across the whole spectrum of ADHF patients, while this is not the case using a single absolute target.

Keywords: Absolute discharge level; Acute decompensated heart failure; NT-proBNP; Relative reduction.