The relationship between B-type natriuretic peptide and health status in patients with heart failure.

BACKGROUND: Although B-type natriuretic peptide (BNP) levels have been proposed as a means of assessing disease severity in patients with heart failure, it is not known if BNP levels are correlated with health status (symptom burden, functional limitation, and quality of life). METHODS AND
RESULTS: We studied 342 outpatients with systolic heart failure from 14 centers at baseline and 6 +/- 2 weeks with BNP levels and the Kansas City Cardiomyopathy Questionnaire (KCCQ), a heart-failure-specific health status instrument. We assessed the correlation between KCCQ scores and BNP at baseline and changes in KCCQ according to changes in BNP levels between baseline and follow-up. Mean baseline BNP levels were 379 +/- 387 pg/mL and mean KCCQ summary scores were 62 +/- 23 points. Although baseline BNP and KCCQ were both associated with New York Heart Association classification (P < .001 for both), BNP and KCCQ were not correlated (r(2) = 0.008, P = .15). There was no significant relationship between changes in BNP and KCCQ regardless of the threshold used to define a clinically meaningful BNP change. For example, using >50% BNP change threshold, KCCQ improved by 3.7 +/- 14.2 in patients with decreasing BNP, improved by 1.7 +/- 13.6 in patients with no BNP change, and improved by 1.0 +/- 13.4 in patients with increasing BNP (P = .6).
CONCLUSION: BNP and health status are not correlated in outpatients with heart failure in the short term. This suggests that these measures may assess different aspects of heart failure severity, and that physiologic measures do not reflect patients' perceptions of the impact of heart failure on their health status.