Kroesen SH; Bakker EA;Snoek JA; van Kimmenade RRJ; Molinger J; Araújo CG; Hopman MTE; Eijsvogels TMH;

Medicine and science in sports and exercise [Med Sci Sports Exerc] 2023 May 15.
Date of Electronic Publication: 2023 May 15.

Introduction: We assessed the cardiorespiratory optimal point (COP) – the minimal VE/VO2 in a given minute of an incremental cardiopulmonary exercise test – in patients with heart failure (HF) and aimed to determine 1) its association with patient and disease characteristics, 2) changes following an exercise-based cardiac rehabilitation program (CR), and 3) the association with clinical outcomes.
Methods: We studied 277 HF patients (67 [58-74] years, 30% female, 72% HFrEF) between 2009 and 2018. Patients participated in a 12- to 24-week CR program, and COP was assessed pre- and post-CR. Patient and disease characteristics and clinical outcomes (mortality and cardiovascular-related hospitalization) were extracted from patient files. The incidence of clinical outcomes was compared across COP tertiles (low: <26.0; moderate: 26.0-30.7; high: >30.7).
Results: Median COP was 28.2 [24.9-32.1] and was reached at 51 ± 15% of VO2peak. Lower age, female sex, higher body mass index, the absence of a pacemaker or the absence of chronic obstructive pulmonary disease and lower NT-proBNP concentrations were associated with a lower COP. Participation in CR reduced COP (-0.8, 95% confidence interval (CI): -1.3; -0.3). Low COP had a reduced risk (adjusted hazard ratio 0.53, 95%CI 0.33; 0.84) for adverse clinical outcomes as compared to high COP.
Conclusions: Classic cardiovascular risk factors are associated with a higher, more unfavorable, COP. CR-based exercise training reduces COP, while a lower COP is associated with a better clinical prognosis. As COP can be established during a submaximal exercise test, this may offer novel risk stratification possibilities for HF care programs.
Competing Interests: Conflict of Interest and Funding Source: This project is supported by a Eurostars Grant (E!114585). All the authors have no conflicts of interest or financial ties to disclose. The results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. The results of the present study do not constitute endorsement by the American College of Sports Medicine.