Abstract 16697: Predictive Value of Cardiopulmonary Exercise Testing Parameters for 1-Year Adverse Outcomes in Ambulatory Advanced Heart Failure

Introduction: Maximal and submaximal cardiopulmonary exercise (CPX) parameters predict heart failure (HF) outcomes, yet the best predictors in advanced ambulatory HF are not known. Hypothesis: We examined the discriminative value of maximal CPX parameters including peak oxygen consumption (peak VO2), VO2 pulse, circulatory power (CP, peak systolic BP x peak VO2), and end tidal pressure CO2 (PetCO2), as well as submaximal parameters of ventilatory efficiency (VE/VCO2 slope), VO2 at anaerobic threshold (VO2AT) and oxygen uptake efficiency slope (OUES) on the combined outcome of LVAD, UNOS 1 transplant or death at 1 year. Methods: REVIVAL enrolled systolic HF pts in INTERMACS profiles 4-7 despite optimal medical therapy and CRT, of whom 273 performed CPX; 64 did not exercise (26 too ill, 38 for non-cardiac issues). ROC curves display the discriminative power of each parameter using censored c-statistics. The best multivariable model was identified by Cox regression. Results: At 1 year, there were 53 events (10 transplants,19 deaths; 24 LVADs). Pts with and without events were comparable for age (61 vs 60 yrs), LVEF (27 vs 29%), and BMI (31 vs 32 kg/m 2 ).) Peak VO2, VO2AT, OUES, PetCO2, and CP were higher in the no event group (all p <0.001), whereas VE/VCO2 slope was lower (p<0.0001); respiratory exchange ratio was not different. Among the 26 pts too sick for exercise, the event rate was 15/26 (58%) compared to 38/273 (14%) in those exercising (HR=6.7, p<0.0001). Figure displays ROC curves and c-indices for CPX parameters. VO2 pulse (HR 1.18, p=0.017), CP (HR 0.86, p=0.005) and VE/VCO2 slope (HR 1.1, p=0.0001) were significant predictors in the multivariable analysis (model c-statistic=0.80). Conclusions: In ambulatory advanced HF, the inability to perform exercise due to being too ill predicts adverse outcome and for those who can exercise, VE/VCO2 slope is the most robust submaximal CPX parameter, while CP was the strongest maximal parameter to predict death, transplant or LVAD at 1 year.