Jonathan Wagner, Max Niemeyer, Denis Infanger, Otmar Pfister, Jonathan Myers; Arno Schmidt-Trucksäss and Raphael Knaier

Frontiers in Physiology | www.frontiersin.org
November 2021 | Volume 12 | Article 775601

Objective: The aim of this study was to analyze whether V˙ O2-kinetics during
cardiopulmonary exercise testing (CPET) is a useful marker for the diagnosis of
heart failure (HF) and to determine which V˙ O2-kinetic parameter distinguishes healthy
participants and patients with HF.
Methods: A total of 526 healthy participants and 79 patients with HF between 20 and
90 years of age performed a CPET. The CPET was preceded by a 3-min low-intensity
warm-up and followed by a 3-min recovery bout. V˙ O2-kinetics was calculated from
the rest to exercise transition of the warm-up bout (on-kinetics), from the exercise to
recovery transition following ramp test termination (off-kinetics) and from the initial delay
of V˙ O2 during the warm-up to ramp test transition (ramp-kinetics).
Results: V˙ O2 off-kinetics showed the highest z-score differences between healthy
participants and patients with HF. Furthermore, off-kinetics was strongly associated
with V˙ O2peak. In contrast, ramp-kinetics and on-kinetics showed only minimal z-score
differences between healthy participants and patients with HF. The best on- and
off-kinetic parameters significantly improved a model to predict the disease severity.
However, there was no relevant additional value of V˙ O2-kinetics when V˙ O2peak was
part of the model.
Conclusion: V˙ O2 off-kinetics appears to be superior for distinguishing patients with HF
and healthy participants compared with V˙ O2 on-kinetics and ramp-kinetics. If V˙ O2peak
cannot be determined, V˙ O2 off-kinetics provides an acceptable substitute. However, the
additional value beyond that of V˙ O2peak cannot be provided by V˙ O2-kinetics.