Abstract 9748: Exercise Oscillatory Breathing and NT-pro-BNP Levels in Stable Heart Failure Provide the Strongest Prediction of Cardiac Outcome when Combining Biomarkers with Cardiopulmonary Exercise Testing
Aims: N-terminal-pro brian natiruretic peptide (NT-pro-BNP) and cardiopulmonary exercise testing (CPET)-derived variables are gold standards for assessing prognosis in heart failure (HF) patients. We sought to refine the prediction of cardiac-related events by performing a combined analysis of NT-pro-BNP with markers of ventilatory inefficiency during exercise.
Methods and Results: 260 patients with stable CHF underwent measurement of plasma NT-pro-BNP levels prior to, at peak exercise and 1 minute recovery phase during a CPET evaluation with determination of peak oxygen uptake (VO2), ventilation to CO2 production (VE/VCO2) slope and exercise periodic breathing (EPB). Blood samples were drawn for standard measurements and for hormonal determinations both at rest and at peak exercise.
Results: After a median follow-up period of 20.6 months, there were 54 cardiac-related deaths. Univariate analysis showed that, among the 6 variables of interest including plasma NT-pro-BNP at rest, at peak exercise and 1 minute recovery, peak VO2, VE/VCO2 slope and EPB. NT-pro-BNP was the strongest independent predictor of cardiac death with equivalent prognostic power and strong correlation among rest, peak exercise and 1 minute recovery. Thus, only NT-pro-BNP at rest was considered (Harrel C: 0.783; CI: 0.722-0.844) followed by VE/VCO2 slope (Harrel C: 0.720; CI: 0.646-0.794), EPB (Harrel C: 0.685; CI: 0.619-0.751), and peak VO2 (Harrel C: 0.618; CI: 0.533-0.704). At bivariate stepwise analysis, among various combinations, NT-pro-BNP at rest along with EPB emerged as the strongest prognostic one (Harrel C: 0.800; CI: 0.737-0.862) to estimate the two-years incidence of cardiac death.
Conclusions: In the refinement for robust predictors of outcome in HF patients, high NT-pro-BNP levels together with EPB led to the most powerful definition. VE/VCO2 slope and peak VO2 did not provide any further prognostic adjunct. A biomarker/CPET approach seems very promising to warrant the continuous implementation in the prognostic work-up of HF patients.
- © 2011 by American Heart Association, Inc.