Saeki H; Kuramoto M; Iida Y; Yasumura K; Arita Y; Ogasawara N;

Circulation reports [Circ Rep] 2023 Mar 31; Vol. 5 (5), pp. 167-176.
Date of Electronic Publication: 2023 Mar 31 (Print Publication: 2023).

Background: In outpatient center-based cardiac rehabilitation (O-CBCR), moderate-intensity continuous training (MICT) based on the anaerobic threshold (AT) determined by cardiopulmonary exercise stress testing is recommended. However, it is unclear whether differences in exercise intensity within the MICT domain affect peak oxygen uptake (%peakV̇O ₂ ).
Methods and Results: We retrospectively evaluated patients who underwent O-CBCR at Japan Community Healthcare Organization Osaka Hospital. Those treated with the constant-load method were designated as Group A (n=38), whereas those treated with the variable-load method were designated as Group B (n=48). Although the change in exercise intensity was significantly greater in Group B by approximately 4.5 W, the change in %peakV̇O₂ was not significantly different between groups. Group A had a significantly longer exercise time than Group B (by approximately 4-5 min). No deaths or hospitalizations occurred in either group. The percentage of episodes with exercise cessation was similar between the 2 groups, but the percentage of episodes with load reduction was significantly higher in Group B, mostly because of the increased heart rate.
Conclusions: In supervised MICT based on AT, the variable-load method increased exercise intensity more than the constant-load method without severe complications, but did not improve %peakV̇O₂ .

Brito GM; do Prado DML; Rezende DA; de Matos LDNJ; Loturco I; Vieira MLC; Alô ROB; Bianchini FR; Pinto AJ; Roschel H; Lemes ÍR; Gualano B;

Frontiers in medicine [Front Med (Lausanne)] 2023 Apr 26; Vol. 10, pp. 1128414.
Date of Electronic Publication: 2023 Apr 26 (Print Publication: 2023).

Introduction: Cardiopulmonary exercise testing (CPET) may capture potential impacts of COVID-19 during exercise. We described CPET data on athletes and physically active individuals with or without cardiorespiratory persistent symptoms.
Methods: Participants’ assessment included medical history and physical examination, cardiac troponin T, resting electrocardiogram, spirometry and CPET. Persistent symptoms were defined as fatigue, dyspnea, chest pain, dizziness, tachycardia, and exertional intolerance persisting >2 months after COVID-19 diagnosis.
Results: A total of 46 participants were included; sixteen (34.8%) were asymptomatic and thirty participants (65.2%) reported persistent symptoms, with fatigue and dyspnea being the most reported ones (43.5 and 28.1%). There were a higher proportion of symptomatic participants with abnormal data for slope of pulmonary ventilation to carbon dioxide production (VE/VCO ₂ slope; p <0.001), end-tidal carbon dioxide pressure at rest (PETCO2 rest; p =0.007), PETCO2 max ( p =0.009), and dysfunctional breathing ( p =0.023) vs. asymptomatic ones. Rates of abnormalities in other CPET variables were comparable between asymptomatic and symptomatic participants. When assessing only elite and highly trained athletes, differences in the rate of abnormal findings between asymptomatic and symptomatic participants were no longer statistically significant, except for expiratory air flow-to-percent of tidal volume ratio (EFL/VT) (more frequent among asymptomatic participants) and dysfunctional breathing ( p =0.008).
Discussion: A considerable proportion of consecutive athletes and physically active individuals presented with abnormalities on CPET after COVID-19, even those who had had no persistent cardiorespiratory symptomatology. However, the lack of control parameters (e.g., pre-infection data) or reference values for athletic populations preclude stablishing the causality between COVID-19 infection and CPET abnormalities as well as the clinical significance of these findings.

Chaumont M; Forton K; Gillet A; Lamotte M;

Healthcare (Basel, Switzerland) [Healthcare (Basel)] 2023 Apr 30; Vol. 11 (9).
Date of Electronic Publication: 2023 Apr 30.

Cardiopulmonary exercise testing (CPET) was limited to peak oxygen consumption analysis (VO ₂ peak), and now the ventilation/carbon dioxide production (VE/VCO₂ ) slope is recognized as having independent prognostic value. Unlike VO₂ peak, the VE/VCO₂ slope does not require maximal effort, making it more feasible. There is no consensus on how to measure the VE/VCO₂ slope; therefore, we assessed whether different methods affect its value. This is a retrospective study assessing sociodemographic data, left ventricular ejection fraction, CPET parameters, and indications of patients referred for CPET. The VE/VCO₂ slope was measured to the first ventilatory threshold (VT1-slope), secondary threshold (VT2-slope), and included all test data (full-slope). Of the 697 CPETs analyzed, 308 reached VT2. All VE/VCO₂ slopes increased with age, regardless of test indications. In patients not reaching VT2, the VT1-slope was 32 vs. 36 ( p < 0.001) for the full-slope; in those surpassing VT2, the VT1-slope was 29 vs. 33 ( p < 0.001) for the VT2-slope and 37 (all p < 0.001) for the full-slope. The mean difference between the submaximal and full-slopes was ±4 units, sufficient to reclassify patients from low to high risk for heart failure or pulmonary hypertension.
We conclude that the method used for determining the VE/VCO₂ slope greatly influences the result, the significant variations limiting its prognostic value. The calculation method must be standardized to improve its prognostic value.

Blokland IJ; Groot FP; Bennekom PDCAM; de Koning DJJ; van Dieen PDJH; Houdijk PDH;

Archives of physical medicine and rehabilitation [Arch Phys Med Rehabil] 2023 May 10.
Date of Electronic Publication: 2023 May 10.

Objective: To provide reference values of cardiorespiratory fitness for individuals post-stroke in clinical rehabilitation and to gain insight in characteristics related to cardiorespiratory fitness post stroke.
Design: A retrospective cohort study. Reference equations of cardiopulmonary fitness corrected for age and sex for the 5 ^th ,25 ^th , 50 ^th , 75 ^th and 95 ^th percentile were constructed with quantile regression analysis. The relation between patient characteristics and cardiorespiratory fitness was determined by linear regression analyses adjusted for sex and age. Multivariate regression models of cardiorespiratory fitness were constructed.
Setting: Clinical rehabilitation centre PARTICIPANTS: 405 individuals post-stroke who performed a cardiopulmonary exercise test as part of clinical rehabilitation between July 2015 and May 2021.
Main Outcome Measures: Cardiorespiratory fitness in terms of peak oxygen uptake (V˙O ₂ peak) and oxygen uptake at ventilatory threshold (V˙O ₂ -VT).
Results: References equations for cardiorespiratory fitness stratified by sex and age were provided based on 405 individuals post-stroke. Median V˙O ₂ peak was 17.8[range 8.4-39.6] ml/kg/min and median V˙O ₂ -VT was 9.7[range 5.9-26.6] ml/kg/min. Cardiorespiratory fitness was lower in individuals who were older, female, using beta-blocker medication and in individuals with higher BMI and lower motor ability.
Conclusions: Population specific reference values of cardiorespiratory fitness for individuals post-stroke corrected for age and sex were presented. These can give individuals post-stroke and health-care providers insight in their cardiorespiratory fitness compared to their peers. Furthermore, they can be used to determine the potential necessity for cardiorespiratory fitness training as part of the rehabilitation program for an individual post-stroke to enhance their fitness, functioning and health. Especially, individuals post-stroke with more mobility limitations and beta-blocker use are at a higher risk of low cardiorespiratory fitness.

Zorn J; Vollrath S; Matits L; Schönfelder M; Schulz SVW; Jerg A; Steinacker JM; Bizjak DA;

PloS one [PLoS One] 2023 May 15; Vol. 18 (5), pp. e0285845.
Date of Electronic Publication: 2023 May 15 (Print Publication: 2023).

Introduction: COVID-19 is a multi-systemic disease which can target the lungs and the cardiovascular system and can also affect parts of the brain for prolonged periods of time. Even healthy athletes without comorbidities can be psychologically affected long-term by COVID-19.
Objective: This study aimed to investigate athletes’ perceived mental stress and recovery levels in daily life, and their maximal aerobic power, at three different time points, post COVID-19.
Methods: In total, 99 athletes (62.6% male), who had been infected by COVID-19, filled out the Recovery Stress Questionnaire for Athletes (REST-Q-Sport) and completed cardiopulmonary exercise testing (endpoint maximal aerobic power output (Pmax)) at the initial screening (t1: 4 months after infection). Follow-up assessments occurred three (t2, n = 37) and seven months after t1 (t3, n = 19).
Results: Subgroup means from the Recovery category were significantly below the reference value of four at all three time points, except “General Recovery” (3.76 (± 0.96), p = 0.275, d = 0.968) at t3.”Overtiredness” (2.34 (± 1.27), p = 0.020, r = 0.224) was significantly above the reference value of two at t1, while all other Stress subgroups were not significantly different from the reference value or were significantly below the maximum threshold of two at t1, t2 and t3. Spearman’s ρ revealed a negative association between Pmax and the subcategories of stress (ρ = -0.54 to ρ = -0.11, p < 0.050), and positive correlations between Pmax and “Somatic Recovery” (ρ = 0.43, p < 0.001) and “General Recovery” (ρ = 0.23, p = 0.040) at t1. Pmax (t1: 3.83 (± 0.99), t2: 3.78 (± 1.14), β = 0.06, p < 0.003) increased significantly from t1 to t2. In addition, REST-Q-Sport indicated a decrease in “Sleep” (t2 = 2.35 (± 0.62), t3 = 2.28(± 0.61), β = -0.18, p < 0.023) at t3, when compared to t2.
Conclusion: The perceived recovery seems to be negatively affected in post COVID-19 athletes. Physical performance post COVID-19 correlates with both “Emotional and Somatic Stress” and “Somatic and General Recovery”, indicating potential mental and physical benefits of exercise. While it is evident that COVID-19, like other viral infections, may have an influence on physical performance, monitoring stress and recovery perceptions of athletes is critical to facilitate their return-to-sports, while minimizing long-term COVID-19 induced negative effects like the athletic objective and subjective perceived recovery and stress levels.

Zimerman A;da Silveira AD; Borges MS; Engster PHB; Schaan TU; de Souza GC; de Souza IPMA; Ritt LEF; Stein R; Berwanger O; Vaduganathan M; Rohde LE;

ESC Heart Fail. 2023 Jun;10(3):1689-1697.
Epub 2023 Feb 21.

AIMS: In this multicentre study, we compared cardio-pulmonary exercise test (CPET) parameters between heart failure (HF) patients classified as New York Heart Association (NYHA) class I and II to assess NYHA performance and prognostic role in mild HF. METHODS AND RESULTS: We included consecutive HF patients in NYHA class I or II who underwent CPET in three Brazilian centres. We analysed the overlap between kernel density estimations for the per cent-predicted peak oxygen consumption (VO2 ), minute ventilation/carbon dioxide production (VE/VCO2 ) slope, and oxygen uptake efficiency slope (OUES) by NYHA class. Area under the receiver-operating characteristic curve (AUC) was used to assess the capacity of per cent-predicted peak VO2 to discriminate between NYHA class I and II. For prognostication, time to all-cause death was used to produce Kaplan-Meier estimates. Of 688 patients included in this study, 42% were classified as NYHA I and 58% as NYHA II, 55% were men, and mean age was 56 years. Median global per cent-predicted peak VO2 was 66.8% (IQR 56-80), VE/VCO2 slope was 36.9 (31.6-43.3), and mean OUES was 1.51 (±0.59). Kernel density overlap between NYHA class I and II was 86% for per cent-predicted peak VO2 , 89% for VE/VCO2 slope, and 84% for OUES. Receiving-operating curve analysis showed a significant, albeit limited performance of per cent-predicted peak VO2 alone to discriminate between NYHA class I vs. II (AUC 0.55, 95% CI 0.51-0.59, P = 0.005). Model accuracy for probability of being classified as NYHA class I (vs. NYHA class II) across the spectrum of the per cent-predicted peak VO2 was limited, with an absolute probability increment of 13% when per cent-predicted peak VO2 increased from 50% to 100%. Overall mortality in NYHA class I and II was not significantly different (P = 0.41), whereas NYHA class III patients displayed a distinctively higher death rate (P < 0.001).
CONCLUSIONS: Patients with chronic HF classified as NYHA I overlapped substantially with those classified as NYHA II in objective physiological measures and prognosis. NYHA classification may represent a poor discriminator of cardiopulmonary capacity in patients with mild HF.

Corda J; E Holland A; Berry CD; Westrupp N; Cox NS;

Pediatric pulmonology [Pediatr Pulmonol] 2023 May 05.
Date of Electronic Publication: 2023 May 05.

Objective: To evaluate the validity and reliability of the modified shuttle 25-level test (MST-25) in children with cystic fibrosis (CF).
Methods: A prospective single center study in clinically stable children with CF. Participants undertook two testing conditions on different days: (1) 2xMST-25 tests; (2) cardiopulmonary exercise test (CPET). Test order was randomized. Nadir oxygen saturation (SpO ₂ ), peak heart rate (HR), breathlessness (modified Borg), rate of perceived exertion (RPE), energy expenditure (EE) and metabolic equivalents (MET) from the MST-25 and CPET were compared to assess validity, while outcomes from 2xMST-25 tests were compared for reliability. CPET was performed using breath-by-breath analysis and EE from the MST-25 obtained using the SenseWear Armband.
Results: Strong correlations were found between MST-25 distance and peak oxygen uptake, peak work and minute ventilation on CPET (all r > 0.7, p < 0.01). Moderate correlations were found between MST-25 distance and CPET for METs (r = 0.5) and HR (r = 0.6). Weak associations between tests were evident for nadir SpO ₂ (r = 0.1), modified Borg (r _s  = 0.2) and RPE (r _s  = 0.2). Test-retest reliability was excellent for MST-25 distance (ICC 0.91), peak EE (ICC 0.99) and peak METs (ICC 0.90). Good reliability was achieved for HR (ICC 0.84) and modified Borg score (ICC 0.77), while moderate reliability for nadir SpO ₂ (ICC 0.64) and RPE (ICC 0.68) was observed.
Conclusion: The MST-25 is a valid and reliable field test for the assessment of exercise capacity in children with CF. The MST-25 can be used to accurately monitor exercise capacity and prescribe exercise training, particularly when CPET is not available.

Weigelt A; Bleck S; Huebner MJ; Rottermann K; Waellisch W; Morhart P; Abu-Tair T; Dittrich S; Schoeffl I;

European journal of pediatrics [Eur J Pediatr] 2023 May 06.
Date of Electronic Publication: 2023 May 06.

Pulmonary function is reduced in children after preterm birth. The variety of subgroups ranges from early to late preterm births. Limitations in pulmonary function can be observed even after late preterm birth without signs of bronchopulmonary dysplasia and/or history of mechanical ventilation. Whether this reduction in lung function is reflected in the cardiopulmonary capacity of these children is unclear. This study aims to investigate the impact of moderate to late premature birth on cardiopulmonary function. Cardiopulmonary exercise testing on a treadmill was performed by 33 former preterm infants between 8 and 10 years of age who were born between 32 + 0 and 36 + 6 weeks of gestation and compared with a control group of 19 children born in term of comparable age and sex. The former preterm children achieved comparable results to the term-born controls with respect to most of the cardiopulmonary exercise parameters [Formula: see text]. The only differences were in a slightly higher oxygen uptake efficiency slope [Formula: see text] and higher peak minute ventilation [Formula: see text] in the group of children born preterm. With respect to heart rate recovery [Formula: see text] and breathing efficiency [Formula: see text], there were no significant differences.
Conclusion:  Children born preterm did not show limitations in cardiopulmonary function in comparison with matched controls.
What Is Known: • Preterm birth is associated with reduced pulmonary function in later life, this is also true for former late preterms. • As a consequence of being born premature, the lungs have not finished their important embryological development. Cardiopulmonary fitness is an important parameter for overall mortality and morbidity in children and adults and a good pulmonary function is therefore paramount.
What Is New: • Children born prematurely were comparable to an age- and sex-matched control group with regards to almost all cardiopulmonary exercise variables. • A significantly higher OUES, a surrogate parameter for VO ₂ peak was found for the group of former preterm children, most likely reflecting on more physical exercise in this group. Importantly, there were no signs of impaired cardiopulmonary function in the group of former preterm children.

Simões RP; Goulart CDL; Caruso FR; de Araújo ASG; de Moura SCG; Catai AM; Dos Santos PB; Camargo PF;
Marinho RS; Mendes RG; Borghi-Silva A;

The American journal of the medical sciences [Am J Med Sci] 2023 May 06.
Date of Electronic Publication: 2023 May 06

Background: The aim of this study was to explore the effects of non-invasive positive pressure ventilation (NIPPV) associated with high-intensity exercise on heart rate (HR) and oxygen uptake (V̇O ₂ ) recovery kinetics in in patients with coexistence of chronic obstructive pulmonary disease (COPD) and heart failure (HF).
Methods: This is a randomized, double blinded, sham-controlled study involving 14 HF-COPD patients, who underwent a lung function test and Doppler echocardiography. On two different days, patients performed incremental cardiopulmonary exercise testing (CPET) and two constant-work rate tests (80% of CPET peak) receiving Sham or NIPPV (bilevel mode – Astral 150) in a random order until the limit of tolerance (Tlim). During exercise, oxyhemoglobin and deoxyhemoglobin were assessed using near-infrared spectroscopy (Oxymon, Artinis Medical Systems, Einsteinweg, Netherland).
Results: The kinetic variables of both V̇O ₂ and HR during the high-intensity constant workload protocol were significantly faster in the NIPPV protocol compared to Sham ventilation (P<0.05). Also, there was a marked improvement in oxygenation and lower deoxygenation of both peripheral and respiratory musculature in TLim during NIPPV when contrasted with Sham ventilation.
Conclusions: NIPPV applied during high-intensity dynamic exercise can effectively improve exercise tolerance, accelerate HR and V̇O ₂ kinetics, improve respiratory and peripheral muscle oxygenation in COPD-HF patients. These beneficial results from the effects of NIPPV may provide evidence and a basis for high-intensity physical training for these patients in cardiopulmonary rehabilitation programs.

Magrì D; Palermo P; Salvioni E; Mapelli M; Gallo G; Vignati C; Mattavelli I; Gugliandolo P; Maruotti A; Di Loro PA; Fiori E; Sciomer S; Agostoni P;

International journal of cardiology [Int J Cardiol] 2023 May 08.
Date of Electronic Publication: 2023 May 08.

Background: Exertional oscillatory breathing (EOV) represents an emerging prognostic marker in heart failure (HF) patients, however little is known about EOV meaning with respect to its disappearance/persistence during cardiopulmonary exercise test (CPET). The present single-center study evaluated EOV clinical and prognostic impact in a large cohort of reduced ejection fraction HF patients (HFrEF) and, contextually, if a specific EOV temporal behavior might be an addictive risk predictor.
Methods and Results: Data from 1.866 HFrEF patients on optimized medical therapy were analysed. The primary cardiovascular (CV) study end-point was cardiovascular death, heart transplantation or LV assistance device (LVAD) implantation at 5-years. For completeness a secondary end-point of total mortality at 5- years was also explored. EOV presence was identified in 251 patients (13%): 142 characterized by EOV early cessation (Group A) and 109 by EOV persistence during the whole CPET (Group B). The entire EOV Group showed worse clinical and functional status than NoEOV Group (n = 1.615) and, within the EOV Group, Group B was characterized by a more severe HF. At CV survival analysis, EOV patients showed a poorer outcome than the NoEOV Group (events 27.1% versus 13.1%, p < 0.001) both unpolished and after matching for main confounders. Instead, no significant differences were found between EOV Group A and B with respect to CV outcome. Conversely the analysis for total mortality failed to be significant.
Conclusions: Our analysis, albeit retrospective, supports the inclusion of EOV into a CPET-centered clinical and prognostic evaluation of the HFrEF patients. EOV characterizes per se a more advanced HFrEF stage with an unfavorable CV outcome. However, the EOV persistence, albeit suggestive of a more severe HF, does not emerge as a further prognostic marker.