How well does B-type natriuretic peptide predict death and cardiac events in patients with heart failure: systematic review.

OBJECTIVE: To assess how well B-type natriuretic peptide (BNP) predicts prognosis in patients with heart failure.
DESIGN: Systematic review of studies assessing BNP for prognosis in patients with heart failure or asymptomatic patients. DATA SOURCES: Electronic searches of Medline and Embase from January 1994 to March 2004 and reference lists of included studies. STUDY SELECTION AND DATA EXTRACTION: We included all studies that estimated the relation between BNP measurement and the risk of death, cardiac death, sudden death, or cardiovascular event in patients with heart failure or asymptomatic patients, including initial values and changes in values in response to treatment. Multivariable models that included both BNP and left ventricular ejection fraction as predictors were used to compare the prognostic value of each variable. Two reviewers independently selected studies and extracted data. DATA SYNTHESIS: 19 studies used BNP to estimate the relative risk of death or cardiovascular events in heart failure patients and five studies in asymptomatic patients. In heart failure patients, each 100 pg/ml increase was associated with a 35% increase in the relative risk of death. BNP was used in 35 multivariable models of prognosis. In nine of the models, it was the only variable to reach significance-that is, other variables contained no prognostic information beyond that of BNP. Even allowing for the scale of the variables, it seems to be a strong indicator of risk.
CONCLUSION: Although systematic reviews of prognostic studies have inherent difficulties, including the possibility of publication bias, the results of the studies in this review show that BNP is a strong prognostic indicator for both asymptomatic patients and for patients with heart failure at all stages of disease.