Prognostic value of cardiopulmonary exercise testing in heart failure with reduced,midrange,and preserved ejection fraction

Background--this study aimed to compare the independent and incremental prognostic value of peak oxygen consumption (vo2) and minute ventilation/carbon dioxide production (ve/vco2) in heart failure (hf) with preserved (hfpef),midrange (hfmef),and reduced (hfref) ejection fraction (lvef). methods and results--in 195 hfpef (lvef ≥50%),144 hfmef (lvef 40-49%),and 630 hfref (lvef < 40%) patients,we assessed the association of cardiopulmonary exercise testing variables with the composite outcome of death,left ventricular assist device implantation,or heart transplantation (256 events; median follow-up of 4.2 years),and 2-year incident hf hospitalization (244 events). in multivariable cox regression analysis,greater association with outcomes in hfpef than hfref were noted with peak vo2 (hr [95% confidence interval]: 0.76 [0.67-0.87] versus 0.87 [0.83-0.90] for the composite outcome,pinteraction=0.052; 0.77 [0.69-0.86] versus 0.92 [0.88-0.95],respectively for hf hospitalization,pinteraction=0.003) and ve/vco2 slope (1.11 [1.06- 1.17] versus 1.04 [1.03-1.06],respectively for the composite outcome,pinteraction=0.012; 1.10 [1.05-1.15] versus 1.04 [1.03- 1.06],respectively for hf hospitalization,pinteraction=0.019). in hfmef,peak vo2 and ve/vco2 slope were associated with the composite outcome (0.79 [0.70-0.90] and 1.12 [1.05-1.19],respectively),while only peak vo2 was related to hf hospitalization (0.81 [0.72-0.92]). in hfpef and hfref,peak vo2 and ve/vco2 slope provided incremental prognostic value beyond clinical variables based on the c-statistic,net reclassification improvement,and integrated diagnostic improvement,with models containing both measures demonstrating the greatest incremental value. conclusions--both peak vo2 and ve/vco2 slope provided incremental value beyond clinical characteristics and lvef for predicting outcomes in hfpef. cardiopulmonary exercise testing variables provided greater risk discrimination in hfpef than hfref. © 2017 the authors.