Peak VO2 is More Potent Than B-Type Natriuretic Peptide as a Prognostic Parameter in Cardiac Patients

Background It is well-known that both B-type natriuretic peptide (BNP) and peak oxygen uptake (VO2) are independent predictors of mortality in patients with heart failure. This study investigates the predictive power of BNP and peak VO2 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 VO2, 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 VO2 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 VO2, 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 VO2 and the 2 combined variables (ie, BNP and peak VO2) were consistently over that of BNP. The integrated AUC indices were 0.80 (peak VO2), 0.81 (peak VO2 and BNP) and 0.70 (BNP), respectively. Conclusions These results indicate that peak VO2 is more potent than BNP for predicting the mortality in patients with mixed cardiac disease. (Circ J 2008; 72: 575 - 581)