Prognostic Value of Cardiopulmonary Exercise Testing in Heart Failure With Reduced, Midrange, and Preserved Ejection Fraction

Abstract

Background

This study aimed to compare the independent and incremental prognostic value of peak oxygen consumption ( VO ₂) and minute ventilation/carbon dioxide production ( VE/ VCO ₂) in heart failure ( HF) with preserved ( HFp EF), midrange ( HFm EF), and reduced ( HFr EF) ejection fraction ( LVEF).

Methods and Results

In 195 HFp EF ( LVEF ≥50%), 144 HFm EF ( LVEF 40–49%), and 630 HFr EF ( 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 HFp EF than HFr EF were noted with peak VO ₂ ( HR [95% confidence interval]: 0.76 [0.67–0.87] versus 0.87 [0.83–0.90] for the composite outcome, P _interaction=0.052; 0.77 [0.69–0.86] versus 0.92 [0.88–0.95], respectively for HF hospitalization, P _interaction=0.003) and VE/ VCO ₂ slope (1.11 [1.06–1.17] versus 1.04 [1.03–1.06], respectively for the composite outcome, P _interaction=0.012; 1.10 [1.05–1.15] versus 1.04 [1.03–1.06], respectively for HF hospitalization, P _interaction=0.019). In HFm EF, peak VO ₂ and VE/ VCO ₂ slope were associated with the composite outcome (0.79 [0.70–0.90] and 1.12 [1.05–1.19], respectively), while only peak VO ₂ was related to HF hospitalization (0.81 [0.72–0.92]). In HFp EF and HFr EF, peak VO ₂ and VE/ VCO ₂ 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 VO ₂ and VE/ VCO ₂ slope provided incremental value beyond clinical characteristics and LVEF for predicting outcomes in HFp EF. Cardiopulmonary exercise testing variables provided greater risk discrimination in HFp EF than HFr EF.