Pernot J; Ribon A; Degano B;

Respiratory medicine and research [Respir Med Res] 2023 Apr 29; Vol. 83, pp. 101022.
Date of Electronic Publication: 2023 Apr 29.

Background: The identification of the first ventilatory threshold (VT1) on an incremental cardiopulmonary exercise test (CPET) is useful to guide exercise reconditioning. However, determination of the VT1 is sometimes difficult in patients with chronic respiratory disease. Our hypothesis was that it would be possible to identify a “clinical threshold” based on patients’ perceptions at which they subjectively consider that they can perform endurance training during a rehabilitation programme.
Methods: Workloads at which patients identified a “clinical threshold” during a submaximal exercise were compared with workloads recorded at VT1 determined during a maximal CPET. Patients with a VT1 and/or a “clinical threshold” obtained at a workload <25 W were excluded from the analysis.
Results: A “clinical threshold” could be determined in the 86 patients included. Data from 63 patients were retained for the analysis, of which only 52 had a VT1 that could be identified. The agreement between the workloads determined at VT1 and at the “clinical threshold” was almost perfect, with a Lin’s concordance coefficient (cc) of 0.82.
Conclusions: In the context of chronic respiratory diseases, it is possible to use patients’ sensations (which are by nature subjective) to identify a workload on a cycle ergometer, which corresponds to the workload at the first ventilatory threshold determined objectively during CPET.
Competing Interests: Declaration of Competing Interest Prof. Degano reports personal fees and non-financial support from GSK, Chiesi, AstraZeneca, Nuvaira, Menarini and Boehringer Ingelheim, outside the submitted work. The other authors declare that they have no conflict of interest for the submitted work. The results of the present study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation.

Schierbauer J; Wolf A; Wachsmuth NB; Maassen N; Schmidt WFJ;

Metabolites [Metabolites] 2023 May 06; Vol. 13 (5).
Date of Electronic Publication: 2023 May 06.

We wanted to determine the influence of total blood volume (BV) and blood lactate quantity on lactate concentrations during incremental exercise. Twenty-six healthy, nonsmoking, heterogeneously trained females (27.5 ± 5.9 ys) performed an incremental cardiopulmonary exercise test on a cycle ergometer during which maximum oxygen uptake (V·O _2max ), lactate concentrations ([La ^– ]) and hemoglobin concentrations ([Hb]) were determined. Hemoglobin mass and blood volume (BV) were determined using an optimised carbon monoxide-rebreathing method. V·O _2max and maximum power (P _max ) ranged between 32 and 62 mL·min ^-1 ·kg ^-1 and 2.3 and 5.5 W·kg ^-1 , respectively. BV ranged between 81 and 121 mL·kg ^-1 of lean body mass and decreased by 280 ± 115 mL (5.7%, p = 0.001) until P _max . At P _max , the [La ^– ] was significantly correlated to the systemic lactate quantity (La ^– , r = 0.84, p < 0.0001) but also significantly negatively correlated to the BV (r = -0.44, p < 0.05). We calculated that the exercise-induced BV shifts significantly reduced the lactate transport capacity by 10.8% ( p < 0.0001). Our results demonstrate that both the total BV and La ^– have a major influence on the resulting [La ^– ] during dynamic exercise. Moreover, the blood La ^– transport capacity might be significantly reduced by the shift in plasma volume. We conclude, that the total BV might be another relevant factor in the interpretation of [La ^– ] during a cardio-pulmonary exercise test.

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.

Bryde R; Martinez MW; Emery MS;

Progress in cardiovascular diseases [Prog Cardiovasc Dis] 2023 May 16.
Date of Electronic Publication: 2023 May 16.

Individuals with hypertrophic cardiomyopathy (HCM) have historically been advised to limit exercise and sports participation to mild-intensity activities due to concerns for sudden cardiac arrest (SCA). However, more contemporary data have shown SCA is rare in patients with HCM and emerging data is shifting towards support for the safety of exercise in this patient population. Recent guidelines endorse exercise in patients with HCM after a comprehensive evaluation and shared-decision making with an expert provider.

Competing Interests: Declaration of Competing Interest Dr. Emery reports personal fees (Advisory Board, Speakers Bureau) from Bristol Meyers Squibb. Dr. Martinez reports compensation for his role with Major League Soccer and from the Bristol Meyers Squibb advisory board. Dr. Bryde has no conflicts to report.

Hedge ET; Amelard R; Hughson RL;

Journal of applied physiology (Bethesda, Md. : 1985) [J Appl Physiol (1985)] 2023 May 18.
Date of Electronic Publication: 2023 May 18.

Non-intrusive estimation of oxygen uptake (V̇O ₂ ) is possible with wearable sensor technology and artificial intelligence. V̇O ₂ kinetics have been accurately predicted during moderate exercise using easy-to-obtain sensor inputs. However, V̇O ₂ prediction algorithms for higher intensity exercise with inherent nonlinearities are still being refined. The purpose of this investigation was to test if a machine learning model can accurately predict dynamic V̇O ₂ across exercise intensities, including slower V̇O ₂ kinetics normally observed during heavy- compared to moderate-intensity exercise. Fifteen young healthy adults (7 females; peak V̇O ₂ : 42±5 mL·min ^-1 ·kg ^-1 ) performed three different pseudorandom binary sequence (PRBS) exercise tests ranging in intensity from low-to-moderate, low-to-heavy, and ventilatory threshold-to-heavy work rates. A temporal convolutional network was trained to predict instantaneous V̇O ₂ , with model inputs including heart rate, percent heart rate reserve, estimated minute ventilation, breathing frequency, and work rate. Frequency domain analyses between V̇O ₂ and work rate were used to evaluate measured and predicted V̇O ₂ kinetics. Predicted V̇O ₂ had low bias (-0.017 L·min ^-1 , 95% limits of agreement: [-0.289, 0.254]), and was very strongly correlated ( r _rm =0.974, p <0.001) with the measured V̇O ₂ . The extracted indicator of kinetics, mean normalized gain (MNG), was not different between predicted and measured V̇O ₂ responses (main effect: p =0.374, η _p ² =0.01), and decreased with increasing exercise intensity (main effect: p <0.001, η _p ² =0.64). Predicted and measured V̇O ₂ kinetics indicators were moderately correlated across repeated measurements (MNG: r _rm =0.680, p <0.001). Therefore, the temporal convolutional network accurately predicted slower V̇O ₂ kinetics with increasing exercise intensity, enabling non-intrusive monitoring of cardiorespiratory dynamics across moderate- and heavy-exercise intensities.

Dun Y; Wu S; Cui N; Thomas RJ; Squires RW; Olson TP; Sylvester KP; Fu S; Zhang C; Gao Y; Du Y; Changsha, Xu N; Liu S;

nternational journal of surgery (London, England) [Int J Surg] 2023 May 19.
Date of Electronic Publication: 2023 May 19.

Background: The role of minute ventilation/carbon dioxide production (/CO2) slope, a ventilation efficiency marker, in predicting short- and long-term health outcomes for patients with non-small-cell lung cancer (NSCLC) undergoing lung resection has not been well investigated.
Material and Methods: This prospective cohort study consecutively enrolled NSCLC patients who underwent a presurgical cardiopulmonary exercise test from November 2014 to December 2019. The association of /CO2 slope with relapse-free survival (RFS), overall survival (OS), and perioperative mortality was evaluated using the Cox proportional hazards and logistic models. Covariates were adjusted using propensity score overlap weighting. The optimal cut-off point of the E/CO2 slope was estimated using the Receiver Operating Characteristics curve. Internal validation was completed through bootstrap resampling.
Results: A cohort of 895 patients (median age [interquartile range], 59 [13] years; 62.5% male) was followed for a median of 40 (range, 1-85) months. Throughout the study there were 247 relapses or deaths and 156 perioperative complications. The incidence rates per 1000 person-years for relapses or deaths were 108.8 and 79.6 among patients with high and low E/CO2 slope, respectively (weighted incidence rate difference per 1000 person-years, 29.21 [95% CI, 7.30 to 51.12]). A E/CO2 slope of ≥31 was associated with shorter RFS (hazard ratio for relapse or death, 1.38 [95% CI, 1.02 to 1.88], P=0.04) and poorer OS (hazard ratio for death, 1.69 [1.15 to 2.48], P=0.02) compared to a lower /CO2 slope. A high E/CO2 slope increased the risk of perioperative morbidity compared with a low E/CO2 slope (odds ratio, 2.32 [1.54 to 3.49], P<0.001).
Conclusions: In patients with operable NSCLC, a high E/CO2 slope was significantly associated with elevated risks of poorer RFS and OS, and perioperative morbidity.

Ohuchi H; Mori A; Kurosaki K; Shiraishi I; Nakai M;

American heart journal [Am Heart J] 2023 May 19.
Date of Electronic Publication: 2023 May 19.

Background: Super-Fontan (SF) is an excellent phenotype of patients with Fontan circulation and normal exercise capacity. This study aimed to clarify the prevalence and clinical correlates and characteristics of SF.
Methods: We reviewed 404 Fontan patients who had undergone cardiopulmonary exercise testing, and the results were compared with clinical profiles.
Results: Seventy-seven (19%) patients had SF, and the post-operative prevalence at 5, 10, 15, 20, and ≥ 25 years was 16 (35%), 30 (39%), 18 (19%), 13 (14%), and 0 (0%), respectively. Compared with non-SF, SF patients were younger (p < 0.001) and were mostly men (p < 0.05). SF was characterized by a current high arterial blood pressure and oxygen saturation (SaO ₂ ), low systemic ventricle (SV) end-diastolic pressure, favorable body composition, superior pulmonary function, preserved hepatorenal and hemostatic functions, and better glucose tolerance (p < 0.05-0.001). Pre-Fontan better SV function, low pulmonary artery resistance, and high SaO ₂ were associated with current SF (p < 0.05-0.01). Furthermore, positive trajectory of exercise capacity and high daily activity during childhood were associated with current adult SF (p < 0.05). During the follow-up, 25 patients died, and 74 patients were unexpectedly hospitalized. There was no death in the SF group, and the rate of hospitalization was 67% lower than that of the non-SF group (p < 0.01-0.001).
Conclusions: The prevalence of SF gradually decreased over time. SF was characterized by preserved multi-end-organ function and an excellent prognosis. Pre-Fontan hemodynamics and post-Fontan childhood daily activity were associated with being adult SF.

Schlagheck ML; Bansi J; Wenzel C; Kuzdas-Sallaberger M; Kiesl D; Gonzenbach R; Zimmer P;

European journal of neurology [Eur J Neurol] 2023 May 20.
Date of Electronic Publication: 2023 May 20.

Background: Valid measurements of cardiorespiratory fitness in persons with multiple sclerosis (pwMS) are essential during inpatient rehabilitation for a precise evaluation of the current health status, for defining appropriate exercise intensities, and for evaluation of exercise intervention studies. We aim (i) to examine the proportion of pwMS that attain the American College of Sports Medicine (ACSM) criteria for maximal effort during graded cardiopulmonary exercise testing (CPET), and (ii) to provide insight into participant characteristics that limit maximal exercise performance.
Methods: This cross-sectional study comprises a retrospective examination of ACSM criteria for maximal effort during graded CPET of n=380 inpatient pwMS (mean age: 48±11 years; 66% female). Chi-square or Fisher’s exact tests were conducted to compare differences in the distribution of criteria achieved. Participants’ characteristics were examined as potential predictors using binary logistic regression.
Results: Only 60% of the overall sample attained a respiratory exchange ratio ≥1.10. With regard to the definition applied, only 24% or 40% of the participants achieved an oxygen consumption plateau, and 17% or 50% attained the heart rate criterion. Forty-six per cent met at least two out of three criteria. The disability status, gender, disease course and body mass index were associated with the attainment of maximal effort.
Conclusions: Our findings suggest that a relevant proportion of inpatient pwMS do not attain common criteria utilized to verify maximal oxygen consumption. Identified predictors for criteria attainment can be used to create models to predict cardiorespiratory fitness and to optimise CPET protocols in restrictive groups of pwMS.

Masood IR; Rezvan PH; Lee K; Vervaet H; Kuo C; Loss K; Menteer J; Souza A; Freyer D; Su JA;

Pediatric cardiology [Pediatr Cardiol] 2023 May 22.
Date of Electronic Publication: 2023 May 22.

Cancer survivors exposed to anthracycline chemotherapy are at risk for developing cardiomyopathy, which may have delayed clinical manifestation. In a retrospective cross-sectional study, we evaluated the utility of cardiopulmonary exercise testing (CPET) for detecting early cardiac disease in 35 pediatric cancer survivors by examining the associations between peak exercise capacity (measured via percent predicted peak VO ₂ ) and resting left ventricular (LV) function on echocardiography and cardiac magnetic resonance imaging (cMRI). We additionally assessed the relationships between LV size on resting echocardiography or cMRI and percent predicted peak VO ₂ since LV growth arrest can occur in anthracycline-exposed patients prior to changes in LV systolic function. We found reduced exercise capacity in this cohort, with low percent predicted peak VO ₂ (62%, IQR: 53-75%). While most patients in our pediatric cohort had normal LV systolic function, we observed associations between percent predicted peak VO ₂ and echocardiographic and cMRI measures of LV size. These findings indicate that CPET may be more sensitive in manifesting early anthracycline-induced cardiomyopathy than echocardiography in pediatric cancer survivors. Our study also highlights the importance of assessing LV size in addition to function in pediatric cancer survivors exposed to anthracyclines.

Holzemer NF; Silveira LJ; Kay J; Khanna AD; Jacobsen RM;

Pediatric cardiology [Pediatr Cardiol] 2023 May 23.
Date of Electronic Publication: 2023 May 23.

Hypertension (HTN) is common in patients with a history of coarctation of the aorta (CoA) and remains underrecognized and undertreated. Studies in the non-coarctation otherwise healthy adult population have correlated an exaggerated blood pressure response during mild to moderate exercise with subsequent diagnosis of HTN. The goal of this study was to determine if blood pressure response to submaximal exercise in normotensive CoA patients correlated with development of HTN.Retrospective chart review was performed in individuals ≥ 13 years old with CoA and no diagnosis of HTN at time of cardiopulmonary exercise testing (CPET). Systolic blood pressure (SBP) during CPET at rest, submax 1 (stage 1 Bruce or minute 2 bicycle ramp), submax 2 (stage 2 Bruce or minute 4 bicycle ramp), and peak were recorded. The primary composite outcome was HTN diagnosis or initiation of anti-hypertensive medications at follow up.There were 177 patients (53% female, median age 18.5 years), of whom 38 patients (21%) met composite outcome during a median follow up of 46 months. Men were more likely to develop hypertension. Age at repair and age at CPET were not significant covariates. At each stage of CPET, SBP was significantly higher in those who met the composite outcome. Submax 2 SBP ≥ 145 mmHg was 75% sensitive, 71% specific in males and 67% sensitive, 76% specific in females for development of composite outcome.Our study shows an exaggerated SBP response to submaximal exercise may portend an increased risk of developing hypertension during short- to mid-term follow up.