Vecchiato M; University of Padova, Padova, ITALY.
Aghi A; Nerini R; Borasio N; Gasperetti A; Quinto G; Battista
F; Bettini S; DI Vincenzo A; Ermolao A; Busetto L; Neunhaeuserer D

Medicine & Science in Sports & Exercise. 56(9):1732-1739, 2024 Sep 01.

PURPOSE: Cardiorespiratory fitness (CRF) is a critical marker of overall
health and a key predictor of morbidity and mortality, but the existing
prediction equations for CRF are primarily derived from general
populations and may not be suitable for patients with obesity.
METHODS: Predicted CRF from different non-exercise prediction equations
was compared with measured CRF of patients with obesity who underwent
maximal cardiopulmonary exercise testing (CPET). Multiple linear
regression was used to develop a population-specific nonexercise CRF
prediction model for treadmill exercise including age, sex, weight,
height, and physical activity level as determinants.
RESULTS: Six hundred sixty patients underwent CPET during the study
period. Within the entire cohort, R2 values had a range of 0.24 to 0.46.
Predicted CRF was statistically different from measured CRF for 19 of the
21 included equations. Only 50% of patients were correctly classified into
the measured CRF categories according to predicted CRF. A multiple model
for CRF prediction (mL.min -1 ) was generated ( R2 = 0.78) and validated
using two cross-validation methods.
CONCLUSIONS: Most used equations provide inaccurate estimates of CRF in
patients with obesity, particularly in cases of severe obesity and low
CRF. Therefore, a new prediction equation was developed and validated
specifically for patients with obesity, offering a more precise tool for
clinical CPET interpretation and risk stratification in this population.

Ariyaratnam JP; Royal Adelaide Hospital, Adelaide, Australia
Elliott AD; Mishima RS; Kadhim K; Emami M; Fitzgerald JL;
Middeldorp M; Sanders P

JACC. Clinical Electrophysiology. 10(7 Pt 2):1608-1619, 2024 Jul.

BACKGROUND: Reduced cardiorespiratory fitness (CRF) is an independent risk
factor for the progression of atrial fibrillation (AF). We hypothesized
that reduced CRF is associated with structural, functional, and electrical
remodeling of the left atrium.
OBJECTIVES: This study sought to correlate objectively assessed CRF with
functional and electrical left atrial (LA) parameters using invasive and
noninvasive assessments.
METHODS: Consecutive patients with symptomatic AF undergoing catheter
ablation were recruited. CRF was objectively quantified pre-ablation by
using cardiopulmonary exercise testing. Using peak oxygen consumption,
participants were classified as preserved CRF (>20 mL/kg/min) or reduced
CRF (<20 mL/kg/min). LA stiffness was assessed invasively with hemodynamic
monitoring and imaging during high-volume LA saline infusion. LA stiffness
was calculated as DELTALA diameter/DELTALA pressure over the course of the
infusion. LA function was assessed with echocardiographic measures of LA
emptying fraction and LA strain. Electrical remodeling was assessed by
using high-density electroanatomical maps for LA voltage and conduction.
RESULTS: In total, 100 participants were recruited; 43 had reduced CRF
and 57 had preserved CRF. Patients with reduced CRF displayed elevated LA
stiffness (P = 0.004), reduced LA emptying fraction (P = 0.006), and
reduced LA reservoir strain (P < 0.001). Reduced CRF was also associated
with reduced LA voltage (P = 0.039) with greater heterogeneity (P = 0.027)
and conduction slowing (P = 0.04) with greater conduction heterogeneity (P
= 0.02). On multivariable analysis, peak oxygen consumption was
independently associated with LA stiffness (P = 0.003) and LA conduction
velocities (P = 0.04)
CONCLUSIONS: Reduced CRF in patients with AF is independently associated
with worse LA disease involving functional and electrical changes.
Improving CRF may be a target for restoring LA function in AF.

Correction to “Cardiopulmonary exercise testing and the 2022 definition of pulmonary hypertension”.

Erratum for: Pulm Circ. 2024 Jun 17;14(2):e12398. doi: 10.1002/pul2.12398. (PMID: 38887743)

Veneman T; Amsterdam UMC location University of Amsterdam, Rehabilitation Medicine, Meibergdreef 9, Amsterdam, The Netherlands
Koopman FS; Oorschot S;de Koning JJ; Bongers BC; Nollet F; Voorn EL;

Archives of physical medicine and rehabilitation [Arch Phys Med Rehabil] 2024 Jul 19.
Date of Electronic Publication: 2024 Jul 19.

Objectives: To determine the content validity of cardiopulmonary exercise testing (CPET) for assessing peak oxygen uptake (VO _2peak ) in neuromuscular diseases (NMD).
Design: Baseline assessment of a randomized controlled trial.
Setting: Academic hospital.
Participants: Eighty-six adults (age: 58.0 ± 13.9 years) with Charcot-Marie-Tooth disease (n=35), post-polio syndrome (n=26), or other NMD (n=25).
Intervention: Not applicable.
Main Outcome Measures: Workload, gas exchange variables, heart rate, and ratings of perceived exertion were measured during CPET on a cycle ergometer, supervised by an experienced trained assessor. Muscle strength of the knee extensors was assessed isometrically with a fixed dynamometer. Criteria for confirming maximal cardiorespiratory effort during CPET were established during 3 consensus meetings with an expert group. The percentage of participants meeting these criteria was assessed to quantify content validity.
Results: The following criteria were established for maximal cardiorespiratory effort; a plateau in oxygen uptake (VO _2plateau ) as primary criterion, or 2 out of 3 secondary criteria; 1) peak respiratory exchange ratio (RER _peak ) ≥1.10, 2), peak heart rate (HR _peak ) ≥85% of predicted maximal heart rate, and 3) peak rating of perceived exertion (RPE _peak ) ≥17 on the 6-20 Borg scale. These criteria were attained by 71 participants (83%). VO _2plateau , RER _peak ≥1.10, HR _peak ≥85%, and RPE _peak ≥17 were attained by respectively 31%, 73%, 69%, and 72% of the participants. Peak workload, VO _2peak , and knee extension muscle strength were significantly higher, and body mass index was lower (all p<0.05), in participants with maximal cardiorespiratory effort compared to other participants.
Conclusions: Most people with NMD achieved maximal cardiorespiratory effort during CPET. Therewith, this study provides high quality evidence of sufficient content validity of VO _2peak as a maximal aerobic capacity measure. Content validity may be lower in more severely affected people with lower physical fitness.

Braga F; Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Milani M; Department of Cardiology, Heart Centre Hasselt, Jessa Hospital, Hasselt, Belgium.
Espinosa G; Goulart Prata Oliveira Milani J; Hansen D; Cipriano G Junior; Myers J;  Mourilhe-Rocha R;

European journal of preventive cardiology [Eur J Prev Cardiol] 2024 Jul 04.
Date of Electronic Publication: 2024 Jul 04.

No abstract available

Chavez-Guevara IA; Faculty of Sports Campus Ensenada, Autonomous University of Baja California, Mexico.;
Helge JW; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Amaro-Gahete FJ; Department of Physiology, Faculty of Medicine, University of Granada,  Spain.

The Journal of physiology [J Physiol] 2024 Jul 07.
Date of Electronic Publication: 2024 Jul 07.

No abstract available

Kasiak P; Medical University of Warsaw, Warsaw, Poland.
Kowalski T; Rębiś K; Klusiewicz A; Sadowska D; Wilk A; Wiecha S;Barylski M; Poliwczak AR; Wierzbiński P; Mamcarz A; Śliż D;

BMC sports science, medicine & rehabilitation [BMC Sports Sci Med Rehabil] 2024 Jul 10; Vol. 16 (1), pp. 151.
Date of Electronic Publication: 2024 Jul 10.

Background: Endurance athletes (EA) are an emerging population of focus for cardiovascular health. The oxygen uptake efficiency plateau (OUEP) is the levelling-off period of ratio between oxygen uptake (VO ₂ ) and ventilation (VE). In the cohort of EA, we externally validated prediction models for OUEP and derived with internal validation a new equation.
Methods: 140 EA underwent a medical assessment and maximal cycling cardiopulmonary exercise test. Participants were 55% male (N = 77, age = 21.4 ± 4.8 years, BMI = 22.6 ± 1.7 kg·m ^- 2 , peak VO ₂  = 4.40 ± 0.64 L·min ^- 1 ) and 45% female (N = 63, age = 23.4 ± 4.3 years, BMI = 22.1 ± 1.6 kg·m ^- 2 , peak VO ₂  = 3.21 ± 0.48 L·min ^- 1 ). OUEP was defined as the highest 90-second continuous value of the ratio between VO ₂ and VE. We used the multivariable stepwise linear regression to develop a new prediction equation for OUEP.
Results: OUEP was 44.2 ± 4.2 mL·L ^- 1 and 41.0 ± 4.8 mL·L ^- 1 for males and females, respectively. In external validation, OUEP was comparable to directly measured and did not differ significantly. The prediction error for males was - 0.42 mL·L ^- 1 (0.94%, p = 0.39), and for females was + 0.33 mL·L ^- 1 (0.81%, p = 0.59). The developed new prediction equation was: 61.37-0.12·height (in cm) + 5.08 (for males). The developed model outperformed the previous. However, the equation explained up to 12.9% of the variance (R = 0.377, R ²  = 0.129, RMSE = 4.39 mL·L ^- 1 ).
Conclusion: OUEP is a stable and transferable cardiorespiratory index. OUEP is minimally affected by fitness level and demographic factors. The predicted OUEP provided promising but limited accuracy among EA. The derived new model is tailored for EA. OUEP could be used to stratify the cardiorespiratory response to exercise and guide training.

Smarz K; Jaxa-Chamiec T; Zaborska B; Tysarowski M; Budaj A;

Original Publication: San Francisco, CA : Public Library of Science
[This corrects the article DOI: 10.1371/journal.pone.0255682.].

Baidats Y; Public Health and Sport Sciences, Medical School, University of Exeter, Exeter, UNITED KINGDOM. & Israel
Kadosh S; Jones AM; Wilkerson D; Velner A;Reuveny R;Segel MJ;

Medicine and science in sports and exercise [Med Sci Sports Exerc] 2024 Jul 11.
Date of Electronic Publication: 2024 Jul 11.

Purpose: We studied the effect of O2 supplementation on physiological response to exercise in patients with moderate to severe interstitial lung disease (ILD).
Methods: 13 patients (age 66 ± 10 yrs., 7 males) with ILD (TLC 71 ± 22% predicted, carbon monoxide diffusion capacity (DLCO) 44 ± 16% predicted) and 13 healthy individuals (age 50 ± 17 yrs., 7 males) were tested. ILD patients performed symptom-limited cardiopulmonary exercise tests and constant work-rate tests (CWRTs) at 80% of the work-rate (WR) at the gas exchange threshold (GET). Tests breathing room air (RA, 21% O2) were compared to tests performed breathing 30% O2. Oxygen-uptake (V̇O2) kinetics were calculated from the CWRT results.
Results: In the ILD group, peak WR, peak V̇O2 and V̇O2 at the GET improved significantly when breathing 30% O2 compared to RA (mean ± SD 66 ± 23 vs 75 ± 26 watts, 15 ± 2 vs 17 ± 4 ml/kg/min and 854 ± 232 vs 932 ± 245 ml/min; p = 0.004, p = 0.001 and p = 0.01, respectively). O2 saturation (SPO2%) at peak exercise was higher with 30% O2 (97 ± 4% vs 88 ± 9%, p = 0.002). The time constant (tau) of V̇O2 kinetics was faster in ILD patients while breathing 30% O2 (41 ± 10 sec) compared to RA (52 ± 14 sec, p = 0.003). There was a negative linear relation between tau and SPO2% with RA (r = -0.76, p = 0.006) and while breathing 30% O2 (r = -0.68, p = 0.02).
Conclusions: Using a clinically applicable level of O2 supplementation (30%) improved maximal, aerobic exercise capacity and V̇O2 kinetics in ILD patients, likely due to increased blood O2 content subsequently increasing the O2 delivery to the working muscles.
Competing Interests: Conflict of Interest and Funding Source: This work was supported by the G. Baum Fund of the Israeli Lung Association, Tel-Aviv. The authors have no conflict of interest and no financial disclosure related to this report.