Author + information
- Georgios S. Tzanis, MD, PhD,
- Stavros K. Dimopoulos, MD, PhD and
- Serafim N. Nanas, MD, PhD∗ ()
- ↵∗1st Critical Care Medicine Department, Cardiopulmonary Exercise Testing and Rehabilitation Laboratory, “Evgenidio Hospital”, National and Kapodistrian University of Athens, 20 Papadiamantopoulou Street, Athens 11528, Greece
We read with interest the State-of-the-Art Review by Malhotra et al. (1) regarding the increasing role of cardiopulmonary exercise testing (CPET) in the field of heart failure (HF). Peak oxygen uptake is a well-established and powerful prognostic parameter, which has been used for risk stratification in HF; however, it is influenced by various factors such as patient’s effort, motivation, familiarization with the procedure, body mass index, technique/protocol used, noncardiac limitation, test termination criteria used, and so on.
Malhotra et al. (1) highlighted the increasing role of submaximal parameters in CPET, which supply predictive information concerning the disease progression regardless of patient’s effort and the other confounding factors limiting maximal exercise. Oxygen uptake at anaerobic threshold, oxygen uptake efficiency slope, ventilatory efficiency slope of minute ventilation (VE) to carbon dioxide output (VCO2), VE/VCO2 slope, which can be calculated until anaerobic threshold) and presence of oscillatory breathing at exercise are remarkable submaximal parameters with significant prognostic value.
However, we would also like to emphasize the important role of the recovery kinetics parameters during CPET assessment in patients with HF. Slow oxygen consumption (Vo2), VCo2, heart rate, and VE kinetics during early recovery period after exercise have been shown to be associated with disease severity, supplying useful information regarding the cardiac, pulmonary, and peripheral systems pathophysiology in these patients (2). These parameters seem to be independent of the patients’ ability to perform a maximal CPET and to patients’ effort resulting in good reproducibility. We have previously shown that heart rate recovery is a strong predictor of mortality and specifically in those patients with intermediate exercise capacity (Vo2p: 10 to 18 ml/kg/min) or with “normal” ventilatory response to exercise (VE/VCo2 slope <34) and that oxygen uptake at early recovery phase after maximal or submaximal CPET (Vo2/t-slope) is associated with the functional capacity in HF (3). Interestingly, a recent elegant study provides evidence that the rate of recovery of oxygen uptake is a stronger predictor of event-free survival than are well-established CPET and clinical markers, such as Vo2p and Heart Failure Severity Score (4). Of particular importance, CPET recovery period parameters might be also used to demonstrate the potential beneficial effects of different exercise training interventions (5) in addition to peak exercise variables.
Clinicians should take into consideration CPET parameters during recovery period after exercise and integrate the extracted information prior to final report with decision making. Researchers should be aware of the potential perspectives that recovery period study can confer in the CPET research applications.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
- Malhotra R.,
- Bakken K.,
- D'Elia E.,
- Lewis G.D.
- Nanas S.,
- Nanas J.,
- Kassiotis C.,
- et al.
- Fortin M.,
- Turgeon P.Y.,
- Nadreau E.,
- et al.
- Georgantas A.,
- Dimopoulos S.,
- Tasoulis A.,
- et al.