Prognostic impact of plasma N-terminal pro-brain natriuretic peptide in severe chronic congestive heart failure: A substudy of the carvedilol prospective randomized cumulative survival (COPERNICUS) trial

Background - The utility of N-terminal proBNP (NT-proBNP) to predict the occurrence of death and hospitalization was prospectively evaluated in the COPERNICUS study, which enrolled patients with an ejection fraction <25% and symptoms of chronic congestive heart failure at rest or on minimal exertion. Methods and Results - Baseline plasma concentrations of NT-proBNP were measured in a subgroup of 814 men and 197 women with symptoms at rest or on minimal exertion who were enrolled in the COPERNICUS study and were randomized to placebo (n=506) or carvedilol (n=505). Values of NT-proBNP were markedly increased despite the requirement that patients be euvolemic before the start of treatment (mean±SD, 3235±4392 pg/mL; median, 1767 pg/mL). By univariate Cox regression analysis, NT-proBNP was found to be a powerful predictor of subsequent all-cause mortality (relative risk [RR], 2.7; 95% CI, 1.7 to 4.3; P=0.0001 for above versus below median) and all-cause mortality or hospitalization for heart failure (RR, 2.4; 95% CI, 1.8 to 3.4; P=0.0001 for above versus below median). The predictive value of NT-proBNP was similar when both placebo and carvedilol patients were analyzed separately. No significant interaction was found between NT-proBNP and treatment group (P=0.93 for above- versus below-median NT-proBNP). Conclusions - NT-proBNP was consistently associated with increased risk for all-cause mortality and for all-cause mortality or hospitalization for heart failure in patients with severe congestive heart failure, even in those who were clinically euvolemic. This marker therefore may be a useful tool in risk stratification of patients with severe congestive heart failure.