Comparison of V̇O₂-Kinetic Parameters for the Management of Heart Failure

Objective: The aim of this study was to analyze whether V̇O₂-kinetics during cardiopulmonary exercise testing (CPET) is a useful marker for the diagnosis of heart failure (HF) and to determine which V̇O₂-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. V̇O₂-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 V̇O₂ during the warm-up to ramp test transition (ramp-kinetics). Results: V̇O₂ off-kinetics showed the highest z-score differences between healthy participants and patients with HF. Furthermore, off-kinetics was strongly associated with V̇O_2peak. 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 V̇O₂-kinetics when V̇O_2peak was part of the model. Conclusion: V̇O₂ off-kinetics appears to be superior for distinguishing patients with HF and healthy participants compared with V̇O₂ on-kinetics and ramp-kinetics. If V̇O_2peak cannot be determined, V̇O₂ off-kinetics provides an acceptable substitute. However, the additional value beyond that of V̇O_2peak cannot be provided by V̇O₂-kinetics.