Abstract 13354: Comparative Analysis of Parameters Derived From Cardiopulmonary Exercise Testing and the Role of Brain Natriuretic Peptide Testing for the Prognostic Assessment of Patients with Heart Failure on Optimal Medical Management
Background Cardiopulmonary exercise testing (CPET) is widely used to evaluate the prognosis of patients with heart failure (HF). However, the prognostic value of peak VO2 in comparison to the slope of the ratio of minute ventilation to carbon dioxide production (VE/VCO2) in patients receiving optimal medical therapy has not been fully elucidated. Further, novel biomarkers like brain natriuretic peptide (BNP) add useful prognostic information in patients with HF. We compared the prognostic impact of peak VO2 and VE/VCO2 and the additional impact of BNP levels in ambulatory HF patients.
Methods We analyzed 424 consecutive patients undergoing CPET at Columbia University Medical Center. The transplant (HTx)/ventricular assist device (VAD) free-survival after CPET was evaluated.
Results The optimal cutoff value of peak VO2 for HTx/VAD-free survival was 11.3 mL/mg/min providing an area under the curve (AUC) of 0.75 (p<0.0001) associated with a sensitivity and specificity of 72.3 and 67.3 %, respectively. The AUC of VE/VCO2 was 0.74 and the cutoff value was 34.8 associated with a sensitivity of 71.1% and a specificity of 71.2%. Both peak VO2 (HR 0.4, CI 0.10-0.69; p<0.0001) and VE/VCO2 (HR 1.03, CI 1.01-1.05; p=0.007) were associated with poor outcome but the association was stronger for peak VO2. The cutoff value of BNP was 506 pg/mL providing an AUC of 0.66, associated with a sensitivity and specificity of 49.2 and 76.8 %. BNP levels did not correlate with peak VO2 or VE/VCO2. The combination of peak VO2 and BNP, calculated as =[0.165385×VO2 (mL/mg/min)]-[0.0005067×BNP(pg/mL)], for HTx/VAD-free survival showed an AUC of 0.78, associated with a sensitivity of 83.1%, a specificity of 65.0% and a predictive accuracy of 80.1% (Figure).
Conclusions Both peak VO2 and VE/VCO2 are useful parameter for prognosis but peak VO2 had a higher impact on mortality in HF patients on optimal medical therapy. The additional information of BNP measurements increases the prognostic value of peak VO2.
- © 2012 by American Heart Association, Inc.