Background: It is well-known that both B-type natriuretic peptide (BNP) and peak oxygen uptake (VO(2)) are independent predictors of mortality in patients with heart failure. This study investigates the predictive power of BNP and peak VO(2) 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 VO(2), 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 VO(2) 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 VO(2), 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 VO(2) and the 2 combined variables (ie, BNP and peak VO(2)) were consistently over that of BNP. The integrated AUC indices were 0.80 (peak VO(2)), 0.81 (peak VO(2) and BNP) and 0.70 (BNP), respectively.
Conclusions: These results indicate that peak VO(2) is more potent than BNP for predicting the mortality in patients with mixed cardiac disease.