Peak V̇O2 is more potent than B-type natriuretic peptide as a prognostic parameter in cardiac patients

Abstract

Background: It is well-known that both B-type natriuretic peptide (BNP) and peak oxygen uptake (V̇O2) are independent predictors of mortality in patients with heart failure. This study investigates the predictive power of BNP and peak V̇O2 for survival in cardiac patients. Methods and Results: A total of 609 patients with cardiac disease participated in the study. They underwent cardiopulmonary exercise testing to determine peak V̇O2, with BNP being measured before exercise testing During 502.5 median follow-up days, 29 patients died of cardiovascular disease. In the univariate Cox proportional hazards analysis, peak V̇O2 and BNP were both found to be significant prognostic indices for survival. The time-dependent ROC curve analysis (Heagerty 2006) was applied to 3 predictors: peak V̇O2, BNP, and then both, with gender and age as adjusted variables. The area under the curve (AUC) compared with the follow-up period curves of peak V̇O2 and the 2 combined variables (ie, BNP and peak V̇O2) were consistently over that of BNP. The integrated AUC indices were 0.80 (peak V̇O2), 0.81 (peak V̇O2 and BNP) and 0.70 (BNP), respectively. Conclusions: These results indicate that peak V̇O2 is more potent than BNP for predicting the mortality in patients with mixed cardiac disease.