Nadruz W Jr, West E, Sengeløv M, Santos M, Groarke JD, Forman
DE, Claggett B, Skali H, Shah AM

J Am Heart Assoc. 2017 Oct 31;6(11)

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.