Treadmill Cardiopulmonary Exercise Testing Research Articles

Peak oxygen uptake during treadmill cardiopulmonary exercise testing: applicability analysis of the FRIEND registry prediction equation in a Brazilian healthy sample

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). Background Peak oxygen uptake (VO2peak) measured by cardiopulmonary exercise testing (CPET) is an important marker for health, physical performance and cardiovascular prognosis. Measured values are compared to reference standards for an adequate individual assessment. However, regional and international heterogeneities for VO2peak values have already been demonstrated by Milani, which may limit the external validation of the predictive equations developed in different nationalities. One of these equations was developed in an American population sample (FRIEND Registry) by Myers, but this equation has never been evaluated for portability in a population sample from the Brazilian Midwest region. Purpose To analyze the applicability of the FRIEND registry prediction equation for treadmill VO2peak in a healthy Brazilian sample from the Midwest region. Methods Cross-sectional study of subjects assessed by CPET in the Brazilian Midwest region between January/2011 to March/2020. The inclusion criteria were CPET performed on a treadmill in healthy subjects aged 20 years or older, and with respiratory exchange ratio ≥ 1.0. The exclusion criteria were any history of cardiovascular or pulmonary disease, presence of cardiovascular risk factors (such as hypertension, diabetes mellitus, current smoking, and obesity) and abnormalities on CPET. Variables were described as median and interquartile range. Statistical comparisons between measured and predicted VO2peak were performed using Spearman correlation test, Wilcoxon signed rank test, and Bland-Altman agreement analysis. Results During the study period, 7,843 CPET were performed and included for eligibility. After applying the inclusion and exclusion criteria, 3,544 assessments of healthy individuals were included (1,574 women; 1,970 men; age 20 to 80 years). The measured and predicted VO2peak were, respectively, 29.4 (25.1; 33.9) and 33.1 (29.5; 36.2) mL/kg/min in females, and 39.4 (34.3; 43.9) and 42.2 (39.1; 45.0) mL/kg/min in males, with significant differences (p < 0.0001). Correlations were significant (p < 0.0001) for both sexes (rho = 0.418 in women and 0.432 in men) (Figure 1). The mean error by the Bland-Altman agreement analysis was similar in both sexes, with a bias of -2.96 mL/kg/min (95% limits of agreement: -14.96 to 9.04 ) in females and a bias of -2.78 mL/kg/min (95% limits of agreement: - 15.39 to 9.83) in males (Figure 2). Conclusions The median values of the measured VO2peak were lower than the predicted values for both sexes, with a significant mean error, which limits the applicability of the FRIEND registry prediction equation in the Brazilian Midwest region population and highlights the international heterogeneity of the variable.

Oxygen uptake efficiency slope measured by cardiopulmonary exercise testing: applicability analysis of the available prediction equations in a Brazilian healthy sample

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). Background Oxygen uptake efficiency slope (OUES) measured by cardiopulmonary exercise testing (CPET) is a measure derived from submaximal oxygen uptake values and has prognostic significance in heart failure patients. Measured values are compared to reference standards for an adequate individual assessment. However, current reference values prediction equations have applicability limitations due to differences in ergometer and sample characteristics (age range and nationatilies), which may impact external validation, as international heterogeneities in peak oxygen uptake values have already been demonstrated by Milani et al. and Peterman et al. Purpose To analyze the applicability of the available prediction equations for OUES in a healthy Brazilian sample from the Midwest region. Methods Cross-sectional study of subjects assessed by treadmill CPET in the Brazilian Midwest region between January/2011 to March/2020. The inclusion criteria were CPET performed on a treadmill in healthy subjects aged 20 years or older, and with respiratory exchange ratio ≥ 1.0. The exclusion criteria were any history of cardiovascular or pulmonary disease, presence of cardiovascular risk factors (such as hypertension, diabetes mellitus, current smoking, and obesity) and abnormalities on CPET. The following available prediction equations were used for comparisons with the measured OUES: 1) Buys et al. from Belgium/Netherlands; 2) Hollemberg et al. from United States; 3) Sun et al. from United States; 4) Brazilian prediction equations calculated in our same sample using sex, age and anthropometric variables. Statistical comparisons between measured and predicted OUES were performed using Spearman correlation test and Bland-Altman agreement analysis. Results During the study period, 7,843 CPETs were performed and included for eligibility. After applying the inclusion and exclusion criteria, 3,544 assessments of healthy individuals were included (1,574 women; 1,970 men; age 20 to 80 years). All correlations between measured and predicted values were significant, with rho ranging from 0.325 to 0.396 in females and from 0.391 to 0.450 in males (Figure 1). The mean errors by the Bland-Altman agreement analysis were heterogeneous between the OUES predition equations, with better results in our Brazilian equation. Greater bias were observed in the equation by Sun et al. for both sexes, in the equation from Buys et al. for females and in the equation by Hollemberg et al. for males (Figure 2). Conclusions The applicability analysis of the international prediction equations for OUES revealed great heterogeneity, limiting the external validation of the available equations, and highlighting the importance of using country-specific reference values for OUES to ensure a correct individual evaluation.

Reproducibility (reliability and agreement) of ventilatory threshold and peak responses during cardiopulmonary exercise test in people with stroke

ABSTRACT Background A cardiopulmonary exercise test (CPET) is used to determine the ventilatory thresholds and to directly assess cardiorespiratory capacity. However, its reproducibility should be tested in people with stroke as sequelae imposed by the stroke may induce important variations among and within each subject, affecting the reproducibility of the physiological responses to CPET. Purpose This cross-sectional repeated measures study design aims to determine the reproducibility of anaerobic threshold (AT), respiratory compensation point (RCP), and maximal cardiorespiratory capacity assessed during a CPET in people with stroke. Methods Twenty-eight subjects with hemiparesis after stroke aging 60 ± 13 years were submitted to two treadmill CPETs with identical protocols. Data Analysis The reproducibility of heart rate (HR) and oxygen consumption (VO2) obtained at AT, RCP, and peak effort was evaluated by systematic error (paired t-test); reliability (ICC and 95% confidence interval); and agreement (typical error and coefficient of variation). Results There were no systematic errors for HR and VO2assessed at AT, RCP, and peak effort (p > 0,05). Reliability was high for these variables during CPET (ICCs > 0.93). Agreement was good for all variables. Typical errors for HR and VO2 assessed at AT, RCP, and peak effort were, respectively, 7, 7, and 8 bpm, and 1.51, 1.44, and 1.57 ml.kg−1.min−1. Coefficients of variation assessed at AT, RCP, and peak effort were, respectively, 5.7, 5.1, and 6.0% for HR and 8.7, 7.3, and 7.5% for VO2. Conclusions HR and VO2 measured at AT, RCP, and peak effort during a treadmill CPET present good reproducibility in people with stroke, showing high reliability and good agreement.

Effects of greater erythroid Cl-/HCO3- transporter (band 3) expression on ventilation and gas exchange during exhaustive exercise.

Band 3 protein is a Cl-/[Formula: see text] transporter on the red blood cell (RBC) surface with an important role in CO2 excretion. Greater band 3 expression by roughly 20% is found in people with the GP.Mur blood type. Intriguingly, a disproportional percentage of those with GP.Mur excel in field-and-track sports. Could higher band 3 activity benefit an individual's physical performance? This study explored the impact of GP.Mur/higher band 3 expression on ventilation and gas exchange during exhaustive exercise. We recruited 36 nonsmoking, elite male athletes (36.1% GP.Mur) from top sports universities to perform incremental exhaustive treadmill cardiopulmonary exercise testing (CPET). We analyzed CPET data with respect to absolute running time and to individual's %running time and %maximal O2 uptake. We found persistently higher respiratory frequencies and slightly lower tidal volume in GP.Mur athletes, resulting in a slightly larger increase of ventilation as the workload intensified. The expiratory duty cycle (Te/Ttot) was persistently longer and inspiratory duty cycle (Ti/Ttot) was persistently shorter for GP.Mur subjects throughout the run. Consequently, end-tidal pressure of carbon dioxide ([Formula: see text], a surrogate marker for alveolar and arterial CO2 tension-[Formula: see text] and [Formula: see text]) was lower in the GP.Mur athletes during the early stages of exercise. In conclusion, athletes with GP.Mur and higher band 3 expression hyperventilate more during exercise in a pattern that uses a greater fraction of time for expiration than inspiration to increase the rate of CO2 excretion than increased tidal volume. This greater ventilation response reduced Pco2 and may help to extend exercise capacity in high-level sports.NEW & NOTEWORTHY Higher expression of the Cl-/[Formula: see text] transporter band 3 anion exchanger-1 (AE1) on the red blood cell membrane, as in people with the GP.Mur blood type, increases the rate of CO2 excretion during exercise.

Oxygen Uptake Efficiency Slope in South American Healthy Adults: COMPREHENSIVE REFERENCE VALUES AND INTERNATIONAL COMPARISONS.

The purpose of this study is to provide comprehensive reference values for oxygen uptake efficiency slope (OUES) in healthy adults. International heterogeneity was also explored through published databases. A cross-sectional study was conducted with treadmill cardiopulmonary exercise testing (CPX) from a Brazilian healthy adult sample, in which absolute OUES and values normalized by weight and body surface area (BSA) were calculated. Data were stratified by sex and age group. Prediction equations were calculated using age and anthropometric variables. International data were pooled and differences were explored using factorial analysis of variance or the t test, as appropriate. The OUES age-related patterns were calculated using regression analysis. A total of 3544 CPX were included (1970 males and 1574 females) and the age ranged from 20-80 yr. Males had higher values than females for OUES, OUES/kg, and OUES/BSA. Lower values were found with aging and the data followed a quadratic regression curve. Reference value tables and predictive equations were provided for absolute and normalized OUES in both sexes. International comparisons of absolute OUES values among Brazilian, European, and Japanese data revealed substantial heterogeneity. The OUES/BSA measure minimized the discrepancies between Brazilian and European data. Our study provided comprehensive OUES reference values in a large healthy adult sample from South America with a wide age range and included absolute and normalized values. Differences observed between Brazilian and European data were reduced in the BSA-normalized OUES.

Modeling Physiological Predictors of Running Velocity for Endurance Athletes.

Background: Properly performed training is a matter of importance for endurance athletes (EA). It allows for achieving better results and safer participation. Recently, the development of machine learning methods has been observed in sports diagnostics. Velocity at anaerobic threshold (VAT), respiratory compensation point (VRCP), and maximal velocity (Vmax) are the variables closely corresponding to endurance performance. The primary aims of this study were to find the strongest predictors of VAT, VRCP, Vmax, to derive and internally validate prediction models for males (1) and females (2) under TRIPOD guidelines, and to assess their machine learning accuracy. Materials and Methods: A total of 4001 EA (nmales = 3300, nfemales = 671; age = 35.56 ± 8.12 years; BMI = 23.66 ± 2.58 kg·m-2; VO2max = 53.20 ± 7.17 mL·min-1·kg-1) underwent treadmill cardiopulmonary exercise testing (CPET) and bioimpedance body composition analysis. XGBoost was used to select running performance predictors. Multivariable linear regression was applied to build prediction models. Ten-fold cross-validation was incorporated for accuracy evaluation during internal validation. Results: Oxygen uptake, blood lactate, pulmonary ventilation, and somatic parameters (BMI, age, and body fat percentage) showed the highest impact on velocity. For VAT R2 = 0.57 (1) and 0.62 (2), derivation RMSE = 0.909 (1); 0.828 (2), validation RMSE = 0.913 (1); 0.838 (2), derivation MAE = 0.708 (1); 0.657 (2), and validation MAE = 0.710 (1); 0.665 (2). For VRCP R2 = 0.62 (1) and 0.67 (2), derivation RMSE = 1.066 (1) and 0.964 (2), validation RMSE = 1.070 (1) and 0.978 (2), derivation MAE = 0.832 (1) and 0.752 (2), validation MAE = 0.060 (1) and 0.763 (2). For Vmax R2 = 0.57 (1) and 0.65 (2), derivation RMSE = 1.202 (1) and 1.095 (2), validation RMSE = 1.205 (1) and 1.111 (2), derivation MAE = 0.943 (1) and 0.861 (2), and validation MAE = 0.944 (1) and 0.881 (2). Conclusions: The use of machine-learning methods allows for the precise determination of predictors of both submaximal and maximal running performance. Prediction models based on selected variables are characterized by high precision and high repeatability. The results can be used to personalize training and adjust the optimal therapeutic protocol in clinical settings, with a target population of EA.

Exercise blood pressure changes and aortic dilatation in male Masters endurance athletes.

With aging, aortic dilatation represents a primary risk factor for acute aortic syndromes.1 Among endurance-trained Masters athletes, clinically relevant aortic dilatation, defined by a diameter at the aortic root (AR) or ascending aorta ≥40 mm, is also common.2 Whether this phenotype represents adaptive vascular remodelling, akin to the ‘athlete’s heart’, vs. a manifestation of overuse pathology is uncertain. We sought to analyse the association between changes in exercise blood pressure (BP) and AR size in a cross-sectional cohort of male Masters endurance athletes. We hypothesized that an increased systolic BP (SBP) response to exercise would be associated with larger AR size. Subjects were taken from a developing registry of healthy Masters endurance athletes recruited from the Atlanta Track Club (Atlanta, GA, USA), a regional running organization, created to study cardiovascular risk in Masters athletes. Fasting blood work and maximal-effort treadmill cardiopulmonary exercise testing (CPET) were obtained on all athletes. Exercise history was self-reported and estimated as weekly metabolic equivalents of task (MET).3 Athletes without established diabetes, hypertension, or coronary artery disease and normal resting and exercise ECG proceeded with trans-thoracic echocardiography and vascular applanation tonometry [carotid-femoral pulse wave velocity (PWV), SphygmoCor, Atcor Medical].

Recumbent Ergometer vs Treadmill Cardiopulmonary Exercise Test in HFpEF: Implications for Chronotropic Response and Exercise Capacity

Cardiopulmonary exercise testing (CPET) can identify mechanisms of exercise intolerance in heart failure with preserved ejection fraction (HFpEF), but exercise modalities with differing body positions (eg, recumbent ergometer, treadmill) are broadly used. In this study, we aimed to determine whether body position affects CPET parameters in patients with HFpEF. Subjects with stable HFpEF (n = 23) underwent noninvasive treadmill CPET, followed by an invasive recumbent-cycle ergometer CPET within 3 months. A comparison group undergoing similar studies included healthy subjects (n = 5) and subjects with pulmonary arterial hypertension (n = 6). The peak oxygen consumption (VO2peak) and peak heart rate were significantly lower in the recumbent vs the upright position (10.1 vs 13.1 mL/kg/min [Δ-3 mL/kg/min]; P < 0.001; and 95 vs 113 bpm [Δ-18 bpm]; P < 0.001, respectively). No significant differences were found in the minute ventilation to carbon dioxide production ratio, end-tidal pressure of carbon dioxide or respiratory exchange ratio. A similar pattern was observed in the comparison groups. Compared to recumbent ergometer, treadmill CPET revealed higher VO2peak and peak heart rate response. When determining chronotropic incompetence to adjust beta-blocker administration in HFpEF, body position should be taken into account.

Peak ventilation during treadmill cardiopulmonary exercise testing: applicability analysis of the FRIEND registry prediction equation in a Brazilian healthy sample

Abstract Background Peak ventilation (VEpeak) measured by cardiopulmonary exercise testing (CPX) is a valuable clinical information, especially in patients with pulmonary diseases. Measured values can be compared to maximal voluntary ventilation or to predicted VEpeak calculated by nonexercise equations. However, the FRIEND Registry prediction equation has never been assessed for portability in a Brazilian population sample. Purpose To analyze the applicability of the FRIEND registry prediction equation for VEpeak during treadmill CPX in a Brazilian healthy sample. Methods Cross-sectional study of subjects assessed by CPX in the Brazilian Midwest region between January/2011 to March/2020. The inclusion criteria were CPX performed on treadmill in healthy individuals aged 20 years or older, and with respiratory exchange ratio ≥1.0. The exclusion criteria were any history of cardiovascular or pulmonary disease, presence of cardiovascular risk factors (such as hypertension, diabetes mellitus, current smoking, and obesity) and abnormalities on CPX. Measured VEpeak values were compared with predicted values calculated using age, sex, and height, according to the FRIEND Registry prediction equation. Variables were described as median and interquartile range. Statistical comparisons between measured and predicted VEpeak were performed using Spearman correlation test, Wilcoxon signed rank test, and Blant-Altman agreement analysis. Results During the study period 7,843 CPX were performed and included for study eligibility. After the inclusion and exclusion criteria were applied, 3,544 healthy individuals' assessments were included [1,574 females and 1,970 males, age 39 (33, 47) years]. The measured and predicted VEpeak were, respectively, 76.8 (66.7, 87.4) and 76.2 (68.5, 83.0) L min–1 in females, with significant difference (p=0.004). In males, the measured and predicted VEpeak were, respectively, 123.0 (107.3, 137.3) and 114.8 (107.5, 120.7) L min–1, also with statistical difference (p&amp;lt;0.001). Correlations were significant (p&amp;lt;0.001) for both sexes (r2=0.424 for females and .421 for males) (Figure 1). Average error was lower for females than males, with bias of 1.22 L min–1 (95% limits of agreement: - 26.95 to 29.39) in females and bias of 8.41 L min–1 (95% limits of agreement: −33.04 to 49.87) in males (Figure 2). Conclusion Measured VEpeak median values were greater than predicted median values for both sexes, with lower average error in females than in males. The significant average error in males limits the prediction equation applicability in the Brazilian population. Thus, the development of a new Brazilian prediction equation is necessary to better evaluate the variable response during CPX in Brazil. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).

Exercise intensity domains determined by heart rate at ventilatory threshold: a comparison of the guideline-directed exercise intensity domains for cardiovascular rehabilitation prescription

Abstract Background Appropriate exercise prescription for cardiovascular diseases patients is a keystone for efficient and safe cardiovascular rehabilitation (CR). Exercise intensity prescribed according to the first and second ventilatory threshold (VT1 and VT2), identified by cardiopulmonary exercise testing (CPET), is considered the gold-standard method. However, because CPET is often not available, percentages of peak heart rate (%HRpeak) or heart rate reserve (%HRR), according to heart rate (HR) response during a conventional exercise test, are very commonly used. Purpose To compare the HR at VT1 and VT2 identified by CPET with the recommended exercise intensity prescription domains according to the Brazilian, American, and European CR guidelines/recommendations. Methods This retrospective cohort study assessed 1,465 treadmill CPETs from adult patients with stable cardiovascular diseases. Inclusion criteria were available VT1 and VT2 identification, sinus rhythm during exercise, and had reached maximal effort (respiratory exchange rate ≥1.10). HR at VT1 and VT2 were compared with the exercise intensity prescription domains recommended by Brazilian CR Guideline 2020, European Position Statement 2022, and the American College of Sports Medicine Guideline 2017, according to the obtained %HRpeak and %HRR. Results After applying the inclusions criteria, a sample of 972 CPETs were included (mean age 57.7±12.0 years, 80.8% males, 81.4% with coronary artery disease, and 26.6% with heart failure). VT1 and VT2 were identified, respectively, at 68.8% (63.8, 74.7) and 89.1 (85.8, 92.2) of the peak HR, and 39.0 (32.9, 45.8) and 78.0 (71.6, 84.5) of the HR reserve, indicating a greater heterogeneity of the latter (Figure 1). We found substantial heterogeneity between the measured %HRpeak and %HRR correspondent to the VT1 and VT2 and the estimated HR exercise intensity domains by compared international recommendations (Figure 2). Conclusion The disparities among currently established guideline-directed exercise domains limits the clinical validity of the use of %HRR and %HRpeak, and further strengthens the importance of performing CPET for an accurate exercise intensity prescription in CR. In the absence of CPET, HR values identified in our study at VT1 and VT2 could be used for guiding moderate-intensity exercise prescription for CVD patients, and the suggested range would be 69 to 89% of %HRpeak or 40 to 78% of %HRR. Current established exercise domains limits should be revised to improve HR-based prescription efficiency and safety. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).Conselho Nacional de Desenvolvimento Científico e Tecnolόgico (CNPq).

Cardiorespiratory fitness and left ventricular function in breast cancer survivors a decade after Epirubicin treatment

Abstract Background Anthracyclines are effective chemotherapeutic agents commonly used in breast cancer (BC) treatment. Cardiotoxicity is a serious adverse effect of anthracyclines, but knowledge of long-term cardiac effects is limited. To our knowledge, no prior study has investigated both cardiorespiratory fitness assessed by peak oxygen consumption (V̇O2 peak) and left ventricular (LV) function in long-term follow up of BC survivors (BCS) treated with anthracyclines. Purpose To assess long-term adverse effects of Epirubicin on cardiorespiratory fitness and LV function in BCS. Methods The CAUSE-trial is an ongoing study comparing exercise effects in BCS of stage I-III BC recruited from the Cancer Registry of Norway and controls with no cancer diagnosis. We present preliminary results from the baseline assessments in this trial. BCS (n=93) treated with Epirubicin between 2008 and 2013 were compared to age-matched controls (n=11). V̇O2 peak was assessed by incremental treadmill cardiopulmonary exercise test and LV function by echocardiography. Results At baseline, BCS were 58±7 years old and had received a cumulative dose of 339±85 mg/m2 Epirubicin 11±1 years before examination. There was no difference in V̇O2 peak between BSC and controls. LV ejection fraction was lower in BCS compared to controls assessed by 2D (57±3% vs. 59±2%, p=0.01) and 3D echocardiography (57±3% vs. 61±4%, p=0.006). LV global longitudinal strain was also lower (in absolute value) in BCS compared to controls (−20.6±1.3% vs. −22.0±1.3%, p=0.002). There was no difference in global work index and efficiency between BCS and controls. Conclusion Our findings indicate no difference in cardiorespiratory fitness between BCS and controls a decade after Epirubicin treatment. Systolic LV function was slightly lower in BCS compared to controls. Importantly, systolic LV function in BCS was within normal range, and the difference is probably not of clinical importance. There was no difference in myocardial work between BCS and controls. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): The Cancer Registry of Norway

Extension of fitness evaluations with muscle oxygen saturation measurements based on near-infrared spectroscopy analysis during cardiopulmonary exercise testing in elite athletes

Abstract Introduction Many cardiovascular parameters of sport adaptation have become an area of detailed research in recent decades. However, details of local circulatory and metabolic processes ongoing in the working muscles during physical exercise need to be revealed. Purpose Our aim was to extend cardiopulmonary exercise testing with near-infrared spectroscopy measurements to focus on observing local changes in the contracting muscles during running. Methods Mixed muscle oxygen saturation values (SmO2) measured in the left vastus lateralis muscle of athletes were analyzed by near-infrared spectroscopy during vita maxima treadmill cardiopulmonary exercise testing with 2-min fingertip lactate measurements. Body composition analysis was carried out with bioimpedance method. One-way repeated measures ANOVA, Tukey post-hoc test, Shapiro–Wilk test and Pearson correlation were used for statistical analysis. Results The results of 66 elite athletes (male: 40; age: 17.9±3.6 y; training: 17.7±6.6 h/w; water polo player: 56, wrestler: 8, basketball player: 2) were analyzed. The 10-second averaged values of the measured saturation values were examined at rest (65.8±11.1%), at the anaerobic threshold (40.7±22.8%), at maximum load (30.2±20.5%) and after 5 minutes of cool-down (70.9±12.8%). Significant differences were measured between the four measurement time points in all pairings. A negative correlation was found between the achieved maximal oxygen uptake and the muscle oxygen saturation values measured at the anaerobic threshold and at the maximal load (respectively r=−0.30, p&amp;lt;0.02; r=−0.32, p&amp;lt;0.01). Oxygen uptake at the end of cool-down was also negatively correlated with muscle oxygen saturation values measured at the anaerobic threshold and at the peak of exercise (respectively r=−0.27, p&amp;lt;0.05; r=−0.27, p&amp;lt;0.05). The fat-free mass of the identical limb showed negative correlation with the muscle oxygen saturation values measured at the anaerobic threshold, at the maximal load and at the cool-down (respectively r=−0.43, p&amp;lt;0.01; r=−0.44, p&amp;lt;0.01; r=−0.35, p&amp;lt;0.01), while positive interactions were observed between the body-fat mass of the same limb and the muscle oxygen saturation values (respectively r=0.51, p&amp;lt;0.01; r=0.55, p&amp;lt;0.01; r=0.41, p&amp;lt;0.01). Muscle oxygen saturation values showed no significant correlations with exercise time, lactate levels, or heart rate measurements. Conclusions By our results, muscle oxygen saturation measurements can be reliably applied during exercise physiological measurements. During exercise, muscle oxygen saturation values negatively correlated with oxygen uptake. At the cool-down phase, a rebound effect could be observed compared to the resting measurements. On the identical limb, the higher the muscle mass was, the higher muscle desaturation could be measured. This easy-to-perform test provides insight into muscle metabolism processes and can help with training planning and athlete follow-up. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This project was supported by a grant from the National Research, Development and Innovation Office (NKFIH) of Hungary (K 135076). Supported by the ÚNKP-21-3-I-SE-68 New National Excellence Program of the Ministry for Innovation and Technology from the Source of the National Research, Development and Innovation fund.

Value of cardiopulmonary exercise test submaximal parameters in the assessment of aortic stenosis patients

Abstract Background Exercise test is recommended for risk stratification of asymptomatic patients with severe aortic stenosis (AS), although a significant number of patients can't perform a maximal exercise test, increasing the potential value of sub-maximal parameters for the assessment of these patients. Aim To assess which parameters could be useful for risk stratification in case of a submaximal Cardiopulmonary Exercise Testing (CPET) in asymptomatic patients with severe AS. Methods Retrospective evaluation of adult patients with asymptomatic severe AS, in a single center, who underwent CPET between December 2016 and November 2021. All patients underwent a treadmill CPET using an exercise protocol with progressive increase in workload. Patients were divided in group A (maximal CPET) or group B, respectively, if respiratory exchange ratio (RER) was &amp;gt;1.10 at peak exercise or below this value. Known parameters accessed in a submaximal CPET were evaluated: mean minute ventilation/carbon dioxide production slope (VE/VCO2), VO2 value in first ventilatory threshold (VT1), peak circulatory power, and oxygen uptake efficiency slope (OUES). Results CPET was performed in 25 patients with severe asymptomatic AS (80 years ± 7 years, 56% male), median AVA was 0.86 cm2 [IQR 0.65–0.95 cm2] and transaortic pressure gradient was 46 mmHg [IQR 41–55 mmHg]. The most used protocol was a ramp slope. Nineteen patients (76%) didn't reach a RER&amp;gt;1.10 (group B) due to respiratory (26%) or peripheral limitation (53%). Comparing both groups, group B patients showed a shorter duration of exercise of (8±3 min vs. 9±4 min, p=0.422), and a lowest mean peak VO2 (16.3±3.6 vs. 20.5±6.9 ml/kg/min, p=0.207). In our population, bivariate analyses demonstrated that OUES was the only submaximal parameter that could discriminate both groups: Group B patients had the lowest values (1.53 [IQR 1.47–1.70] vs. 1.94 [IQR 1.56–2.11], p=0.042). ROC curve analysis of OUES values revealed an AUC of 0.78 (p=0.042) for maximal CPET prediction. The cut-off point with most sensitivity (S) and specificity (E) obtained using the Youden index (0.62) was 1.9 (S≈67%; E≈95%) (Figure 1). Conclusions In our cohort of asymptomatic AS patients, even with submaximal CPET, OUES accurately identify patients with higher degrees of functional limitation. Whether OUES is useful as prognostic marker to the workflow treatment of AS it's worth to be assessed prospectively. Funding Acknowledgement Type of funding sources: None.

Cardiorespiratory Function Following Aerobic Exercise Training In Women With Systemic Lupus Erythematosus

The vast majority (~80%) of patients with systemic lupus erythematosus (SLE) report severe, debilitating fatigue and studies have suggested that SLE-fatigue associates with decreased cardiorespiratory function in these patients. Conversely, there has been inconsistency regarding the influence of exercise training on cardiorespiratory fitness in patients with SLE. PURPOSE: The purpose of this study was to examine the influence of a vigorous 12-week aerobic exercise training regimen (AET) on cardiorespiratory function and functional aerobic impairment (FAI) in women with SLE. METHODS: Sixteen women (age: 42 ± 10 years) with SLE (SELENA-SLEDAI <4) participated in supervised AET on the treadmill for 12 weeks at an intensity of 70 to 80% of heart rate reserve. The thrice-weekly sessions were 30 minutes in duration. All subjects completed a treadmill cardiopulmonary exercise test (CPET) before and after completion of exercise training. FAI was calculated as the percent difference between observed V̇O2 peak and predicted VO2 peak based on age, sex, and activity status. Paired sample t-tests were used to compare FAI scores before and after AET. RESULTS: There was a significant (p = 0.01) improvement in peak VO2 after AET (pre: 21.7 ml/kg/min ± 3.5; post: 23.1 ml/kg/min ± 3.8). FAI was observed in 25% of participants at baseline. However, a significant improvement in group FAI score (p = 0.01) was observed after AET (pre: 20.1% ± 12; post: 14.9% ± 11.5). Of the participants with FAI at baseline, 75% improved FAI classification after participating in AET. CONCLUSION: Findings from this study suggest that 12 weeks of supervised AET may improve cardiorespiratory function in patients with SLE and possibly reverse FAI in some of these patients. Funding: NIH/IRP ZIA CL060096

Early flattening of the oxygen pulse during the cardiopulmonary exercise test in asymptomatic adults and its association with cardiovascular risk factors

BackgroundIndividuals with cardiovascular exercise limitations present oxygen pulse morphology with early flattening (plateau) during the cardiopulmonary exercise test (CPET). Although this oxygen pulse response is well known in cardiac patients, these changes' prevalence and clinical relevance in asymptomatic individuals are not known. We aimed to quantify the proportion of asymptomatic adults with an early flattening of the oxygen pulse and investigate its association with classical cardiovascular risk factors. MethodsWe carried out a cross-sectional study with a sample of 824 adults aged between 18 and 80 years. We assessed anthropometry, body composition, and cardiovascular risk. In addition, we obtained cardiorespiratory and metabolic responses during a ramp protocol treadmill CPET. ResultsThe prevalence of early flattening of the oxygen pulse was 36.8%. These participants were predominantly females, older, less educated, with a higher body mass and percentage of fat and a lower percentage of lean body mass. After a multinominal multiple logistic regression analysis, we identified female sex (odds ratio, 5.46: 95% confidence interval, 3.73–7.99), low education (2.24: 1.47–3.42), dyslipidemia (1.67: 1.14–2.45), smoking (1.64: 1.00–2.69), and physical inactivity (1.39: 1.02–1.96) as the leading independent predictors of the early flattening of oxygen pulse. ConclusionThe early flattening of oxygen pulse is common in asymptomatic adults and is highly determined by modifiable cardiovascular risk factors. These results suggest that identifying the early flattening of oxygen pulse may be helpful in the prevention of cardiovascular diseases.

Cardiorespiratory Insufficiency and Performance Fatigability in Women with Systemic Lupus Erythematosus.

Patients with systemic lupus erythematosus (SLE) experience excessive, debilitating fatigue with previously reported evidence of etiologically mediated cardiorespiratory impairments. Performance fatigability provides a precise characterization of fatigue as it can be quantified objectively as a function of time, frequency, and/or duration. Nevertheless, little consideration has been given to understanding performance fatigability and its physiological determinants in those with SLE. The purpose of this study was to characterize performance fatigability in patients with SLE, utilizing measures surrounding the anaerobic threshold, with emphasis on cardiorespiratory impairment as a potential mediating factor. This was a case-control study design. 44 physically inactive women, 26 with SLE and 18 controls, completed a treadmill cardiopulmonary exercise test to volitional exhaustion. There were no significant differences in age (SLE 34.8(9.0) vs Control 36.9(7.3) yrs; p=0.422) between groups. BMI (SLE 27.1(5.4) vs Control 23.8(5.2) kg/m2; p=0.045) was significantly higher in the SLE vs Control group. Resting heart rate (SLE 68(16) vs Control 78(15) bpm; p=0.040) was significantly lower in the SLE compared to the Control group. The VO2 corresponding to the anaerobic threshold (AT-VO2), used to identify the onset of exercise-induced fatigue, was significantly lower in women with SLE than in controls (SLE 12.4(3.1) vs Control 16.4(2.2) ml/kg/min; p<0.001), as was AT-stage (SLE 2.5(0.90) vs Control 3.4(0.78); p=0.002). Additionally, Fatigue Severity Score (FSS) was highly and inversely correlated with AT-VO2 (rho=-0.615; p<0.001) and FSS was highly correlated with Functional Aerobic Impairment Index (FAI; rho=0.663; p<0.001). This study underscores severe performance fatigability in patients with SLE and its link to cardiorespiratory insufficiency. Physiological presentation of performance fatigability was observed during very low intensities of exercise, emphasizing the negative impact it may have on physical function in this population.

Exercise Capacity in Patients with Pulmonary Atresia with Intact Ventricular Septum: Does the Type of Surgical Repair Matter?

Two standard surgical palliative options for neonates born with pulmonary atresia and intact ventricular septum (PA/IVS) include uni-or biventricular repair. Whenever feasible, the biventricular repair is considered to have better exercise capacity (XC) and outcomes. However, there is a paucity of data comparing objective XC between these two surgical techniques.Our aim was to compare XC, including longitudinal changes in patients with PA/IVS following uni-biventricular repair. We performed a single-center retrospective study of survivors with repaired PA/IVS who underwent comprehensive treadmill cardiopulmonary exercise testing. Initial and latest exercise parameters were compared for longitudinal analysis. Demographic and exercise parameters were collated. Peak oxygen uptake (VO2 in ml/kg/min), an indicator of maximal aerobic capacity, peak heart rate, and other measures of spirometry performed at the same time were collected. Recorded parameters included, (a) Percentage of predicted VO2 (% VO2) normalized for age, weight, height, and gender, (b) % oxygen (O2) pulse, (c) anaerobic threshold (AT), (d) Chronotropic index (CI), (e) % Breathing reserve, (f) Forced vital capacity (FVC), (g) % Forced Expiratory volume in 1s (FEV1), (h) Maximum voluntary ventilation (MVV), and (i) VE/VCO2. Appropriate statistical tests were performed, and a p value < 0.05 was considered significant. A total of 35 patients (43% male, 57% univentricular repair) were included,witha mean (SD) age of 20.1(7.5)years. Patients with univentricular palliation demonstrated significantly impaired peak heart rate, chronotropic index (0.50 ± 0.2 vs. 0.90 ± 0.1, p = 0.02), VE/VCO2 (35.4 ± 5.0 vs. 30.2 ± 2.8, p = 0.001), and %FVC (78.3 ± 8.3 vs. 88.6 ± 15.1, p = 0.02). There was a trend towards reduction in % VO2 in the Fontan patients though it was statistically similar between the groups (68.4 ± 21.4 vs. 81.2 ± 18.9, p = 0.07).Longitudinal data were available for 11 patients in each group, and there was no longitudinal decline in their exercise parameters over similar intermediate follow-up duration [6.8 (UV) vs. 5.3 (BV) years]. We conclude thatyoung survivors with PA/IVS with prior univentricular palliation demonstrated an objective impairment in their chronotropic parameters compared with the biventricular repair. However, this did not translate into a significant difference in their exercise capacity. There was no longitudinal decline in exercise capacity or other parameters over intermediate follow-up.

Cardiopulmonary exercise testing and efficacy of percutaneous coronary intervention: a substudy of the ORBITA trial.

AimsOxygen-pulse morphology and gas exchange analysis measured during cardiopulmonary exercise testing (CPET) has been associated with myocardial ischaemia. The aim of this analysis was to examine the relationship between CPET parameters, myocardial ischaemia and anginal symptoms in patients with chronic coronary syndrome and to determine the ability of these parameters to predict the placebo-controlled response to percutaneous coronary intervention (PCI).Methods and resultsPatients with severe single-vessel coronary artery disease (CAD) were randomized 1:1 to PCI or placebo in the ORBITA trial. Subjects underwent pre-randomization treadmill CPET, dobutamine stress echocardiography (DSE) and symptom assessment. These assessments were repeated at the end of a 6-week blinded follow-up period.A total of 195 patients with CPET data were randomized (102 PCI, 93 placebo). Patients in whom an oxygen-pulse plateau was observed during CPET had higher (more ischaemic) DSE score [+0.82 segments; 95% confidence interval (CI): 0.40 to 1.25, P = 0.0068] and lower fractional flow reserve (−0.07; 95% CI: −0.12 to −0.02, P = 0.011) compared with those without. At lower (more abnormal) oxygen-pulse slopes, there was a larger improvement of the placebo-controlled effect of PCI on DSE score [oxygen-pulse plateau presence (Pinteraction = 0.026) and oxygen-pulse gradient (Pinteraction = 0.023)] and Seattle angina physical-limitation score [oxygen-pulse plateau presence (Pinteraction = 0.037)]. Impaired peak VO2, VE/VCO2 slope, peak oxygen-pulse, and oxygen uptake efficacy slope was significantly associated with higher symptom burden but did not relate to severity of ischaemia or predict response to PCI.ConclusionAlthough selected CPET parameters relate to severity of angina symptoms and quality of life, only an oxygen-pulse plateau detects the severity of myocardial ischaemia and predicts the placebo-controlled efficacy of PCI in patients with single-vessel CAD.

Exercise Capacity After Arterial Switch Operation in Patients with D-Transposition of Great Arteries: Does the Coronary Artery Anatomy Matter?

Variant coronary anatomy (VarCA) is frequent in D-Transposition of the great arteries (d-TGA). There are a paucity of data on the effect of the VarCA on the exercise capacity (XC) in patients with repaired d-TGA. This retrospective study included patients with d-TGA who underwent an arterial switch operation (ASO) and had at least one cardiopulmonary exercise test (CPET). Data from the treadmill CPET and simultaneously performed spirometry were collected. The parameters of CPET were compared between patients with usual anatomy vs. VarCA. Longitudinal changes in XC in patients with ASO were also analyzed. A total of 44 patients with either usual coronary anatomy (n = 27, 61%) or VarCA (n = 17, 39%) met inclusion criteria. There was no significant difference in oxygen consumption (%VO2) at initial CPET (104 vs. 100%, p = 0.53) between the two groups. Abnormal %VO2 (< 85%) was uncommon in both groups (n = 2, 7.4% vs. n = 4; 23.5%; p = ns). For longitudinal changes, there was no significant decline in %VO2 in either group: (i) usual coronary anatomy (n = 15, median follow-up 4.8years, %VO2 111 vs. 108%; p = 0.306) and (ii) VarCA (n = 10, median follow-up 6.6years, %VO2 106 vs. 92%; p = 0.441). Spirometry was abnormal in 25 (59.5%) patients [restrictive (n = 8, 19.0%), obstructive (n = 15, 35.7%), and mixed (n = 2, 4.8%)] butabnormal spirometry had no impact on the XC. Patients with d-TGA who underwent neonatal ASO uniformly exhibited good XC without any longitudinal decline on medium-term follow-up, regardless of coronary artery anatomy. Although frequent (60%), abnormal spirometry was not associated with reduced exercise capacity.

Comparison of two methods of cardiopulmonary exercise testing for assessing physical fitness in children and adolescents with extreme obesity

It is well-known that children and adolescents with obesity have increased over recent decades which in turn carries greater risk of co-morbidities and poses a preventive as well as a therapeutic challenge. Currently, there are limited recommendations available on proven methods for recording physical fitness in children and adolescents presenting with extreme obesity. In this study, twenty participants, aged 12–17 years, with a body mass index (BMI) above the 99.5th percentile, were comparatively assessed, using a correlation between their physical fitness on a bicycle (BC) and treadmill (TM) cardiopulmonary exercise testing (CPET) with a lactate diagnostic. The results of the BC and the TM were as follows: maximum heart rate (HRmax) 186.4 ± 8.6 beats per minute (bpm) vs. 190.8 ± 8.8 bpm, peak oxygen consumption (VO2peak/kg) 23.5 ± 2.9 ml/min/kg vs. 25.4 ± 3.1 ml/min/kg, and maximum lactate (Lamax) 6.4 ± 1.6 mmol/l vs. 5.6 ± 1.4 mmol/l. The values of HRmax and VO2peak/kg were significantly higher for adolescents tested on the TM. However, no significant difference was observed in either Lamax values or between the genders. Conclusions: The higher values of HRmax and VO2peak/kg could be attributed to the activation of a higher percentage of muscle mass on the TM. Lower Lamax values on the TM suggest maximum physical exertion was not achieved. This could be due to the extreme body weight carried by the participants. Both the BC and the TM CPET could be used for assessing physical fitness in children and adolescents with extreme obesity but should not be used interchangeably.What is Known:• Currently, there are only limited recommendations available on proven methods for recording physical fitness in children and adolescents with extreme obesity available.What is New:• Cardiopulmonary exercise testing with maximum physical exertion has been shown to be feasible in children and adolescents with extreme obesity. The results obtained from this study demonstrated that both a bicycle and a treadmill can be effectively used for assessing the physical fitness levels in children and adolescents with extreme obesity.