Objectives: Using a prospective study design, we assessed the value of brain natriuretic peptide (BNP) to identify patients with heart failure who have an increased risk of deterioration of their functional status. Furthermore, we examined the relationship between BNP and various clinical characteristics incorporated into an established survival model used for risk stratification.
Background: Prediction of the clinical course is a crucial part of the decision-making process about the adequate treatment strategy for patients with advanced congestive heart failure (CHF). Although laborious, multivariable indexes have been established for risk stratification, simple plasma BNP measurements may be as useful as prognostic indicators.
Methods: In 78 patients referred to our heart failure clinic, plasma BNP levels were compared with the results of a multivariable prognostic model. To assess the prognostic power of BNP, the clinical course of this cohort was monitored for a median follow-up period of 398 days.
Results: At study entry, plasma BNP and the heart failure survival score (HFSS) showed a significant correlation (r = -0.706). During follow-up, Kaplan-Meier estimates of freedom from clinical events differed significantly for patients above and below the 75th percentile concentrations of plasma BNP (p < 0.0001). Changes in plasma BNP were significantly related to changes in limitations of physical activity, as demonstrated by logistic regression analysis (chi-square statistic = 24.9, p < 0.0001). Proportional hazards analysis confirmed BNP as a powerful predictor of functional status deterioration (p < 0.0001). This prognostic information was as powerful as that derived from the multivariable HFSS.
Conclusions: Measurement of plasma BNP concentrations might provide a useful and cost-effective screening tool that helps reduce the need and frequency for more expensive cardiac tests.