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Insomnia treatment among individuals with comorbid insomnia and obstructive sleep apnea is suboptimal. In a pilot randomized controlled trial, 19 individuals with comorbid insomnia and obstructive sleep apnea were allocated to one of two arms: EX + EX, consisting of two 8-week phases of exercise training (EX), or RE + CBTiEX, encompassing 8 weeks of relaxation training (RE) followed by 8 weeks of combined cognitive-behavioral therapy and exercise (CBTiEX). Outcomes included Insomnia Severity Index (ISI), polysomnography, and cardiorespiratory fitness measures. A mixed-model analysis of variance revealed a Group × Time interaction on peak oxygen consumption change, F(1, 14) = 10.1, p =.007, and EX increased peak oxygen consumption (p =.03, g′ = −0.41) and reduced ISI (p =.001, g′ = 0.82) compared with RE (p =.49, g = 0.16) post-8 weeks. Post-16 weeks, there was a significant Group × Time interaction (p =.014) driven by RE + CBTiEX yielding a larger improvement in ISI (p =.023, g′ = 1.48) than EX + EX (p =.88, g′ < 0.1). Objective sleep was unchanged. This study showed promising effects of regular EX alone and combined with cognitive-behavioral therapy for insomnia on ISI in comorbid insomnia and obstructive sleep apnea. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusions To identify the association between cardiopulmonary exercise testing (CPET) and outcomes of radical cystectomy (RC), as RC is historically associated with high rates of short‐ and long‐term morbidity and mortality.This quantitative systematic review and meta‐analysis was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta‐Analysis guidelines. An electronic literature search was conducted to identify all relevant studies evaluating the relationship between CPET parameters and RC outcomes. The primary outcome was short‐term mortality. Secondary outcomes included hospital length of stay (LOS) and rate of serious adverse events as defined by the Clavien–Dindo classification.The search identified six studies for inclusion. A total of 546 patients underwent CPET prior to RC. There were significantly more deaths following RC observed in patients with poorer cardiopulmonary function (risk ratio RR 5.80, 95% confidence interval 4.96–6.78). There was no significant association between CPET parameters and adverse events or hospital LOS.The present systematic review and meta‐analysis identified a greater risk of 90‐day mortality in patients with poorer cardiorespiratory function, as measured by CPET. However, there remains a paucity of robust clinical data and further high‐quality studies are required to verify these results. [ABSTRACT FROM AUTHOR]

An excessive rise in systolic blood pressure (SBP) during exercise has been linked to increased risk of cardiovascular disease. Hypertensive individuals have been shown to have an exaggerated blood pressure (BP) response to exercise. However, research is limited on the impact of chronic antihypertensive medication use on the exercise BP response. Purpose: To determine if individuals chronically (>1 yr) prescribed antihypertensive medications have a normal BP response to peak exercise compared with unmedicated individuals. Methods: Participants included 2555 adults from the Ball State Adult Fitness Longitudinal Lifestyle STudy cohort who performed a peak treadmill exercise test. Participants were divided into groups by sex and antihypertensive medication status. Individuals prescribed antihypertensive medications for >1 yr were included. Exaggerated and blunted SBP within each group was categorized using the Fitness Registry and the Importance of Exercise: A National Database (FRIEND) and absolute criteria as noted by the American Heart Association. Results: The unmedicated group had a greater prevalence (P < 0.05) of blunted SBP responses, whereas the medicated group had a higher prevalence (P < 0.05) of exaggerated SBP responses using both the FRIEND and absolute criteria. Peak SBP was higher (P < 0.01) in medicated compared with unmedicated participants in the overall cohort when controlling for age and sex, but not after controlling for resting SBP (P = 0.613), risk factors (P = 0.104), or cardiorespiratory fitness (P = 0.191).When men and women were assessed independently, peak SBP remained higher in the medicated women after controlling for age and resting SBP (P = 0.039), but not for men (P = 0.311). Individuals on betablockers had a higher peak SBP even after controlling for age, sex, risk factors, and cardiorespiratory fitness (P = 0.022).Conclusions: Individuals on antihypertensive medications have a higher peak SBP response to exercise. Given the prognostic value of exaggerated peak SBP, control of exercise BP should be considered in routine BP assessment and in the treatment of hypertension. [ABSTRACT FROM AUTHOR]

Purpose: Approximately 30%of people infected with COVID-19 require hospitalization, and 20% of them are admitted to an intensive care unit (ICU). Most of these patients experience symptoms of fatigue weeks post-ICU, so understanding the factors associated with fatigue in this population is crucial. Methods: Fifty-nine patients (38-78 yr) hospitalized in ICU for COVID-19 infection for 32 (6-80) d, including 23 (3-57) d of mechanical ventilation, visited the laboratory on two separate occasions. The first visit occurred 52 ± 15 d after discharge and was dedicated to questionnaires, blood sampling, and cardiopulmonary exercise testing, whereas measurements of the knee extensors neuromuscular function and performance fatigability were performed in the second visit 7 ± 2 d later. Results: Using the FACIT-F questionnaire, 56% of patients were classified as fatigued. Fatigued patients had worse lung function score than non-fatigued (i.e., 2.9 ± 0.8 L vs 3.6 ± 0.8 L; 2.4 ± 0.7 L vs 3.0 ± 0.7 L for forced vital capacity and forced expiratory volume in 1 s, respectively), and forced vital capacity was identified as a predictor of being fatigued. Maximal voluntary activation was lower in fatigued patients than non-fatigued patients (82% ± 14% vs 91% ± 3%) and was the only neuromuscular variable that discriminated between fatigued and non-fatigued patients. Patient-reported outcomes also showed differences between fatigued and non-fatigued patients for sleep, physical activity, depression, and quality of life (P < 0.05). Conclusions: COVID-19 survivors showed altered respiratory function 4 to 8 wk after discharge, which was further deteriorated in fatigued patients. Fatigue was also associated with lower voluntary activation and patient-reported impairments (i.e., sleep satisfaction, quality of life, or depressive state). The present study reinforces the importance of exercise intervention and rehabilitation to counteract cardiorespiratory and neuromuscular impairments of COVID-19 patients admitted in ICU, especially individuals experiencing fatigue. [ABSTRACT FROM AUTHOR]

Introduction: Cardiopulmonary exercise testing (CPET) is the gold standard for measuring exercise capacity, however, it is resource intensive and has limited availability. This study aimed to determine: 1) the association between the 6‐min walk test (6MWT) and the 30‐s sit‐to‐stand test (30STS) with CPET peak oxygen uptake (VO2peak) and anaerobic threshold (AT) and 2) 6MWT and 30STS cut points associated with a higher risk of postoperative complications. Methods: A cross‐sectional study, retrospectively analyzing data collected from a tertiary cancer center over a 23‐month period. Measures included CPET VO2peak and AT, 6MWT and 30STS test. Correlations were used to characterize relationships between variables. Receiver operating characteristic curve analyses determined 6MWT and 30STS cut points that aligned with CPET variable cut points. Results: Note that, 156 participants were included. The 6MWT and 30STS displayed moderate correlations with VO2peak, rho = 0.65, p = 0.01 and rho = 0.52, p < 0.005 respectively. Fair correlations were observed between AT and 6MWT (rho = 0.36, p = 0.01) and 30STS (rho = 0.41, p < 0.005). The optimal cut points to identify VO2peak < 15 mL/kg/min were 493.5 m on the 6MWT and 12.5 stands on the 30STS test and for AT < 11 mL/kg/min were 506.5 m on the 6MWT and 12.5 stands on the 30STS test. Conclusion: Both the 6MWT and 30STS test could be used as alternative tools for measuring exercise capacity preoperatively in the cancer setting where CPET is not available. A range of 6MWT and 30STS cut points, according to sensitivity and specificity levels, may be used to evaluate risk of postoperative outcomes. [ABSTRACT FROM AUTHOR]

Background: Pulmonary arterial hypertension (PAH) is a common complication of chronic obstructive pulmonary disease (COPD), which can lead to shorter survival and poor clinical outcomes. Patients suffering from PAH display a cardiopulmonary exercise testing (CPET) profile with several atypical factors, such as decreased work rate, limited ability to do aerobic activities, and ventilatory insufficiency. Objectives: To assess and compare exercise tolerance by CPET in COPD patients with secondary PAH receiving cGMP-specific phosphodiesterase type-5 (PDE-5) inhibitor (sildenafil) versus those who are receiving standard-of-care only. Patients and methods: This is a prospective, cross-sectional research in which a total of 30 COPD patients with mild to severe obstruction and secondary PAH were recruited; all patients were treated with standard-of-care treatment for COPD; moreover, half of the recruited patients were also on sildenafil 60 mg/day for at least 3 months at the time of recruitment (sildenafil users) as specific therapy for PAH while the other half were not (non-users). All patients underwent CPET to assess their exercise capacity. Results: No significant statistical differences were observed between sildenafil users and non-users in all CPET parameters except in respiratory exchange ratio (RER) during both exercise and recovery with sildenafil users showing a lower RER in both phases compared to non-users (p = 0.02, 0.01, respectively). Also, resting diastolic blood pressure (DBP) was significantly lower in sildenafil users (p = 0.02). In addition, sildenafil users did not exhibit significant differences compared to non-users in terms of Modified Medical Research Council (mMRC) score, COPD assessment test (CAT) score, or spirometric parameters. Conclusion: Our findings suggest that there were no significant differences in overall exercise capacity, nor in symptoms or spirometric parameters between COPD patients with secondary PAH receiving sildenafil and those who were not. [ABSTRACT FROM AUTHOR]

Abstract Aims Although cardiopulmonary exercise testing (CPET) is the gold standard to assess exercise capacity, simpler tests (i.e., 6‐min walk test, 6MWT) are also commonly used. The aim of this study was to evaluate the relationship between cardiorespiratory parameters during CPET and 6MWT in a large, multicentre, heterogeneous population. Methods We included athletes, healthy subjects, and heart failure (HF) patients of different severity, including left ventricular assist device (LVAD) carriers, who underwent both CPET and 6MWT with oxygen consumption measurement. Results We enrolled 186 subjects (16 athletes, 40 healthy, 115 non‐LVAD HF patients, and 15 LVAD carriers). CPET‐peakV̇O2 was 41.0 [35.0–45.8], 26.2 [23.1–31.0], 12.8 [11.1–15.3], and 15.2 [13.6–15.6] ml/Kg/min in athletes, healthy, HF patients, and LVAD carriers, respectively (P

Purpose of Review: Cardiac amyloidosis (CA) constitutes an important etiology of heart failure with preserved ejection fraction (HFpEF) or heart failure with mildly reduced ejection fraction (HFmrEF). Since patients with CA show early exhaustion, we aimed to investigate whether non-exertional variables of cardiopulmonary exercise testing (CPET) provide additional information in comparison to traditional peak oxygen consumption (VO2peak). Recent Findings: We retrospectively investigated CPET variables of patients with HFpEF and HFmrEF with (n = 21) and without (n = 21, HF) CA at comparable age and ejection fraction. Exertional and non-exertional CPET variables as well as laboratory and echocardiographic markers were analyzed. The primary outcome was the difference in CPET variables between groups. The secondary outcome was rehospitalization in patients with CA during a follow-up of 24 months. Correlations between CPET, NTproBNP, and echocardiographic variables were calculated to detect patterns of discrimination between the groups. HF patients with CA were inferior to controls in most exertional and non-exertional CPET variables. Patients with CA were hospitalized more often (p = 0.002), and rehospitalization was associated with VE/VCO2 (p = 0.019), peak oxygen pulse (p = 0.042), the oxygen equivalent at the first ventilatory threshold (p = 0.003), circulatory (p = 0.024), and ventilatory power (p <.001), but not VO2peak (p = 0.127). Higher performance was correlated with lower E/e' and NTproBNP as well as higher resting heart rate and stroke volume in CA. Summary: Patients with CA displayed worse non-exertional CPET performance compared to non-CA HF patients, which was associated with rehospitalization. Differences between correlations of resting echocardiography and CPET variables between groups emphasize different properties of exercise physiology despite comparable ejection fraction. [ABSTRACT FROM AUTHOR]

Background: Exercise training in patients with HCM has evidenced benefits on functional capacity, cardiac function, and a reversion of adverse cardiac remodeling. The objective of this study was to assess the effect of a concurrent resistance and cardiorespiratory training program on functional capacity, biochemical parameters, and echocardiographic variables in a pilot group. Methods: Two HCM patients were evaluated before and after 12 weeks of individualized concurrent training with two sessions/week. Pre- and post-training data were compared for each patient. Evaluations included a cardiopulmonary exercise test (CPET), body composition, echocardiography, electrocardiography, and blood analysis. Results: Training promoted an increase in functional capacity (+4 mL·kg−1·min−1), ventilatory thresholds, and other CPET-derived variables associated with a better prognosis and long-term survival. Muscular mass was augmented (0.8 and 1.2 kg), along with a mean increase of 62% in upper and lower body strength. Echocardiographic features demonstrated the maintenance of cardiac function with signs of positive left ventricular remodeling and an improvement in diastolic function. Blood analyses, including cardiac troponins and NT-proBNP, displayed uneven changes in each patient, but the values fell into normal ranges in both cases. Conclusions: The available data suggest a positive effect of concurrent resistance and cardiorespiratory training on patients' functional capacity and cardiac function that may improve their functional class, quality of life, and long-term prognosis. The replication of this protocol in a larger cohort of patients is warranted to confirm these preliminary results. [ABSTRACT FROM AUTHOR]

Background: Cardiopulmonary exercise testing is not used routinely. The goal of this study was to determine whether accurate estimates of VO2 values can be made at the beginning and at the end of a rehabilitation program. Methods: A total of 91 cardiac rehabilitation patients were included. Each participant had to complete cardiopulmonary exercise testing at the beginning and at the end of a rehabilitation program. Measured VO2 values were compared with estimates based on three different equations. Results: Analyses of the means of the differences in the peak values showed very good agreement between the results obtained with the FRIEND equation or those obtained with a combination of rules of thumb and the results of the measurements. This agreement was confirmed with the ICCs and with the standard errors of the measurements. The ACSM equation performed worse. The same tendency was seen when considering the VO2 values at percentage-derived work rates. Conclusions: The FRIEND equation and the more easily applicable combination of rules of thumb are suitable for estimating the peak VO2 and the VO2 at a percentage-derived work rate in cardiac patients both at the beginning and at the end of a cardiac rehabilitation program. [ABSTRACT FROM AUTHOR]

Introduction: An essential process affecting the course of type 1 diabetes (DM1) is the appearance and duration of clinical remission. One of the most important factors promoting the occurrence of remission is physical activity, due to increased activity of antioxidants, reduces insulin resistance and improves glucose transport. Maximal oxygen capacity (VO2max) is an objective measure of the body's aerobic capacity. To assess VO2max, oxygen uptake should be measured directly during the exercise test. The aim of the study was to evaluate the physical capacity in adults with DM1 and its relationship with the occurrence of partial clinical remission (pCR) during 2 years follow-up. Methods: The pCR was assessed by the following mathematical formula: A1c (%) + [4 × insulin dose (U/kg/d)]. The result ⩽9 indicates pCR. VO2max was assessed between 6th and 24th month of diabetes duration using an ergospirometer (COSMED K5 System), during an exercise test carried out on a cycloergometer (RAMP incremental exercise test). Results: The study group consisted of 32 adults with DM1. People with pCR were proved to have higher VO2max level [36.0 (33.0-41.5) vs 30.9 (26.5-34.4) ml/min/kg, P =.009. Univariate and multivariate regression confirmed a significant association between VO2max and presence of pCR [AOR 1.26 (1.05-1.52), P =.015]. Duration of remission was longer among group with higher VO2max results [15 (9-24) vs 9 (0-12) months, P =.043]. The positive relationship was observed between diabetes duration and VO2max (rs = 0.484, P =.005). Multivariate linear regression confirms a significant association between remission duration and VO2max (ml/min/kg) (β = 0.595, P =.002). Conclusion: The higher VO2max, the better chance of partial clinical remission at 2 years of DM1 and longer duration of remission. Plain Language Summary: Better cardiorespiratory fitness increases the chance of partial clinical remission and prolongs remission duration in people with newly diagnosed type 1 diabetes. Introduction An essential process affecting the course of type 1 diabetes (DM1) is the appearance and duration of clinical remission. One of the most important factors promoting the occurrence of remission is physical activity, due to increased activity of antioxidants, reduces insulin resistance and improves glucose transport. Maximal oxygen capacity (VO2max) is an objective measure of the body's aerobic capacity. To assess VO2max, oxygen uptake should be measured directly during the exercise test. The aim of the study was to evaluate the physical capacity in adults with DM1 and its relationship with the occurrence of partial clinical remission (pCR) during 2 years follow-up. Methods The pCR was assessed by the following mathematical formula: A1c (%) + [4 × insulin dose (U/kg/d)]. The result ⩽9 indicates pCR. VO2max was assessed between 6th and 24th month of diabetes duration using an ergospirometer (COSMED K5 System), during an exercise test carried out on a cycloergometer (RAMP incremental exercise test). Results The study group consisted of 32 adults with DM1. People with pCR were proved to have higher VO2max level [36.0 (33.0-41.5) vs 30.9 (26.5-34.4) ml/min/kg, P =.009. Univariate and multivariate regression confirmed a significant association between VO2max and presence of pCR [AOR 1.26 (1.05-1.52), P =.015]. Duration of remission was longer among group with higher VO2max results [15 (9-24) vs 9 (0-12) months, P =.043]. The positive relationship was observed between diabetes duration and VO2max (rs = 0.484, P =.005). Multivariate linear regression confirms a significant association between remission duration and VO2max (ml/min/kg) (β = 0.595, P =.002). Conclusions The higher VO2max, the better chance of partial clinical remission at 2 years of DM1 and longer duration of remission. [ABSTRACT FROM AUTHOR]

Aims: Although cardiopulmonary exercise testing (CPET) is the gold standard to assess exercise capacity, simpler tests (i.e., 6‐min walk test, 6MWT) are also commonly used. The aim of this study was to evaluate the relationship between cardiorespiratory parameters during CPET and 6MWT in a large, multicentre, heterogeneous population. Methods: We included athletes, healthy subjects, and heart failure (HF) patients of different severity, including left ventricular assist device (LVAD) carriers, who underwent both CPET and 6MWT with oxygen consumption measurement. Results: We enrolled 186 subjects (16 athletes, 40 healthy, 115 non‐LVAD HF patients, and 15 LVAD carriers). CPET‐peakV̇O2 was 41.0 [35.0–45.8], 26.2 [23.1–31.0], 12.8 [11.1–15.3], and 15.2 [13.6–15.6] ml/Kg/min in athletes, healthy, HF patients, and LVAD carriers, respectively (P < 0.001). During 6MWT they used 63.5 [56.3–76.8], 72.0 [57.8–81.0], 95.5 [80.3–109], and 95.0 [92.0–99.0] % of their peakV̇O2, respectively. None of the athletes, 1 healthy (2.5%), 30 HF patients (26.1%), and 1 LVAD carrier (6.7%), reached a 6MWT‐V̇O2 higher than their CPET‐peakV̇O2. Both 6MWT‐V̇O2 and walked distance were significantly associated with CPET‐peakV̇O2 in the whole population (R2 = 0.637 and R2 = 0.533, P ≤ 0.001) but not in the sub‐groups. This was confirmed after adjustment for groups. Conclusions: The 6MWT can be a maximal effort especially in most severe HF patients and suggest that, in absence of prognostic studies related to 6MWT metabolic values, CPET should remain the first method of choice in the functional assessment of patients with HF as well as in sport medicine. [ABSTRACT FROM AUTHOR]

Background Peak oxygen consumption (peak V̇O2$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$) is routinely measured in people who have congenital heart disease and is reported as a percentage of predicted value, based upon age‐ and sex‐matched normative reference values (NRVs). This study aimed to identify which NRVs are being used, assess whether NRVs are being applied appropriately, and evaluate if recommended NRVs are valid when applied to people with congenital heart disease. Methods and Results A systematic scoping review identified studies that reported peak V̇O2$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$ percentage of predicted value in people with congenital heart disease. A modified risk of bias tool evaluated the included studies. Forty‐five studies reported peak V̇O2$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$ percentage of predicted value, and only 21 (47%) studies described or provided a reference on how their percentage of predicted value was calculated. The most cited NRVs were from Wasserman (n=12) and Cooper and Weiler‐Ravell (n=7). Risk of bias analysis judged 63% of studies as having some concerns. The NRVs recommended by the American Heart Association were applied to participants with a Fontan circulation (n=70; aged 26.5±6.4 years; 59% women) to examine validity. Predicted peak V̇O2$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$ values from the Wasserman NRV was not significantly associated to measured peak V̇O2$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$ values (men: b=0.31, R2≤0.01; women: b=0.07, R2=0.02). Conclusions Numerous NRVs have been applied to individuals with congenital heart disease and are often poorly reported and inappropriately matched to participants. The Wasserman NRV was the most cited but showed poor validity when applied to a Fontan cohort.

Background: Peak oxygen consumption and oxygen pulse along with their respective percent predicted measures are gold standards of exercise capacity. To date, no studies have investigated the relationship between percent predicted peak oxygen pulse (%PredO2P) and ventricular-vascular response (VVR) and the association of %PredO2P with all-cause mortality in heart failure with preserved ejection fraction (HFpEF) patients. Objectives: The authors investigated the association between: 1) CPET measures of %PredO2P and VVR; and 2) %PredO2P and all-cause mortality in HFpEF patients. Methods: Our cohort of 154 HFpEF patients underwent invasive CPET and were grouped into %PredO2P tertiles. The association between percent predicted Fick components and markers of VVR (ie, proportionate pulse pressure, effective arterial elastance) was determined with correlation analysis. The Cox proportional hazards model was used to identify predictors of mortality. Results: The participants’ mean age was 57 ± 15 years. Higher %PredO2P correlated with higher exercise capacity. In terms of VVR, higher %PredO2P correlated with a lower pressure for a given preload (effective arterial elastance r = −0.45, P

IntroductionAdvanced heart failure (HF) is an epidemic that affects multiple organ systems with high morbidity and mortality rates despite optimal medical therapy (OMT) and remains the leading cause of hospitalizations in type 2 diabetes-related cardiovascular disease. The addition of sodium-glucose co-transporter inhibitors (SGLT2i) in treating these patients has seen improved mortality and hospital admission rates. As such, we felt it was important to investigate whether the use of SGLT2i improved functional capacity in patients with HF when compared to OMT by evaluating maximum oxygen consumption (peak VO2) using cardiopulmonary exercise testing (CPET).MethodsWe found 94 heart failure patients between August 2020 and August 2021 who underwent CPET before and after treatment at Mayo Clinic in Florida. 50 patients received OMT and 44 received OMT and SGLT2i therapy. CPET results before and after were compared for each group.ResultsThe baseline ejection fraction was not significantly different between groups, with the OMT group at 38% and the SGLT2i group at 33%, p = 0.10. OMT patients were found to have a significantly lower hemoglobin A1c of 5.7 (5.4–6.1) compared to those with SGLT2i therapy of 6.4 (5.8–7.1), p = 0.01. The baseline peak VO2 was 17.3 ml/kg/min (13.3–21.6) in the OMT group and 17.3 ml/kg/min (14.4–18.9) in the SGLT2i group, p = 0.18, not significantly different. The interesting finding is that the follow-up peak VO2 at one year for the OMT group was 17 ml/kg/min (13.3–21.6), which was not significantly different from the SGLT2i group peak VO2 of 17 ml/kg/min (14.6–19.6), p = 0.19. Our study is the first to compare before and after peak VO2 values of the OMT+SGLT2i group to the patient's own baseline and we found no significant improvement.ConclusionOur single-center data shows no improvement in functional capacity after the addition of SGLT2i therapy to OMT in patients with advanced heart failure. Improved hospitalization and symptoms may be attributed to other numerous effects of SGLT2i such as volume management.

BACKGROUND: Cardiopulmonary exercise testing is an increasingly common test and is considered the accepted standard for assessing exercise capacity. Quantifying variability is important to assess the instrument for quality control purposes. Though guidelines recommend biologic control testing, there are minimal data on how to do it. We sought to describe variability for oxygen consumption (V̇O2 ), carbon dioxide production (V̇CO2 ), and minute ventilation (V̇E) at various work rates under steady-state conditions in multiple subjects over a 1-y period to provide a practical approach to assess and perform biologic control testing. METHODS: We performed a single-center, prospective study with 4 healthy subjects, 2 men and 2 women. Subjects performed constant work rate exercise tests for 6 min each at 25-100 W intervals on a computer-controlled cycle ergometer. Data were averaged over the last 120 s at each work rate to reflect stepwise steady-state conditions. Descriptive statistics, including the mean, median, range, SD, and coefficient of variation (CoV) are reported for each individual across the 4 work rates and all repetitions. As these data were normative, z-scores were utilized, and a value greater than ± 1.96 z-scores was used to define significant test variability. RESULTS: Subjects performed 16-39 biocontrol studies over 1-y. The mean CoV for all subjects in V̇O2 was 6.59%, V̇CO2 was 6.41%, and V̇E was 6.32%. The ± 1.96 z-scores corresponded to a 9.4-18.1% change in V̇O2 , a 9.6-18.1% change in V̇CO2 , and a 9-21.5% change in V̇E across the 4 workloads. CONCLUSIONS: We report long-term variability for steady-state measurement of V̇O2 , V̇CO2 , and V̇E obtained during biocontrol testing. Utilizing ± 1.96 z-scores allows one to determine if a result exceeds expected variability, which may warrant investigation of the instrument.

Physiological response to physical exercise through analysis of cardiopulmonary measurements has been shown to be predictive of a variety of diseases. Nonetheless, the clinical use of exercise testing remains limited because interpretation of test results requires experience and specialized training. Additionally, until this work no methods have identified which dynamic gas exchange or heart rate responses influence an individual's decision to start or stop physical activity. This research examines the use of advanced machine learning methods to predict completion of a test consisting of multiple exercise bouts by a group of healthy children and adolescents. All participants could complete the ten bouts at low or moderate-intensity work rates, however, when the bout work rates were high-intensity, 50% refused to begin the subsequent exercise bout before all ten bouts had been completed (task failure). We explored machine learning strategies to model the relationship between the physiological time series, the participant's anthropometric variables, and the binary outcome variable indicating whether the participant completed the test. The best performing model, a generalized spectral additive model with functional and scalar covariates, achieved 93.6% classification accuracy and an F1 score of 93.5%. Additionally, functional analysis of variance testing showed that participants in the 'failed' and 'success' groups have significantly different functional means in three signals: heart rate, oxygen uptake rate, and carbon dioxide uptake rate. Overall, these results show the capability of functional data analysis with generalized spectral additive models to identify key differences in the exercise-induced responses of participants in multiple bout exercise testing.

Studies using cardiopulmonary exercise testing (CPET) to evaluate persistent dyspnea following infection with COVID‐19 have focused on older patients with co‐morbid diseases who are post‐hospitalization. Less attention has been given to younger patients with post‐COVID‐19 dyspnea treated as outpatients for their acute infection. We sought to determine causes of persistent dyspnea in younger patients recovering from acute COVID‐19 infection that did not require hospitalization. We collected data on all post‐COVID‐19 patients who underwent CPET in our clinic in the calendar year 2021. Data on cardiac function and respiratory response were abstracted, and diagnoses were assigned using established criteria. CPET data on 45 patients (238.3 ± 124 days post‐test positivity) with a median age of 27.0 (22.0–40.0) were available for analysis. All but two (95.6%) were active‐duty service members. The group showed substantial loss of aerobic capacity—average VO2 peak (L/min) was 84.2 ± 23% predicted and 25 (55.2%) were below the threshold for normal. Spirometry, diffusion capacity, high‐resolution computed tomography, and echocardiogram were largely normal and were not correlated with VO2peak. The two most common contributors to dyspnea and exercise limitation following comprehensive evaluation were deconditioning and dysfunctional breathing (DB). Younger active‐duty military patients with persistent dyspnea following outpatient COVID‐19 infection show a substantial reduction in aerobic capacity that is not driven by structural cardiopulmonary disease. Deconditioning and DB breathing are common contributors to their exercise limitation. The chronicity and severity of symptoms accompanied by DB could be consistent with an underlying myopathy in some patients, a disorder that cannot be differentiated from deconditioning using non‐invasive CPET. [ABSTRACT FROM AUTHOR]

Background 25-hydroxyvitamin D can undergo C-3 epimerization to produce 3-epi-25(OH)D3. 3-epi-25(OH)D3 levels decline in chronic kidney disease (CKD), but its role in regulating the cardiovascular system is unknown. Herein, we examined the relationship between 3-epi-25(OH)D3, and cardiovascular functional and structural endpoints in patients with CKD. Methods We examined n  = 165 patients with advanced CKD from the Cardiopulmonary Exercise Testing in Renal Failure and After Kidney Transplantation (CAPER) study cohort, including those who underwent kidney transplant (KTR, n  = 76) and waitlisted patients who did not (NTWC, n  = 89). All patients underwent cardiopulmonary exercise testing and echocardiography at baseline, 2 months and 12 months. Serum 3-epi-25(OH)D3 was analyzed by liquid chromatography-tandem mass spectrometry. Results Patients were stratified into quartiles of baseline 3-epi-25(OH)D3 (Q1: <0.4 ng/mL, n  = 51; Q2: 0.4 ng/mL, n  = 26; Q3: 0.5–0.7 ng/mL, n  = 47; Q4: ≥0.8 ng/mL, n  = 41). Patients in Q1 exhibited lower peak oxygen uptake [VO2Peak = 18.4 (16.2–20.8) mL/min/kg] compared with Q4 [20.8 (18.6–23.2) mL/min/kg; P  = .009]. Linear mixed regression model showed that 3-epi-25(OH)D3 levels increased in KTR [from 0.47 (0.30) ng/mL to 0.90 (0.45) ng/mL] and declined in NTWC [from 0.61 (0.32) ng/mL to 0.45 (0.29) ng/mL; P  < .001]. Serum 3-epi-25(OH)D3 was associated with VO2Peak longitudinally in both groups [KTR: β (standard error) = 2.53 (0.56), P  < .001; NTWC: 2.73 (0.70), P  < .001], but was not with left ventricular mass or arterial stiffness. Non-epimeric 25(OH)D3, 24,25(OH)2D3 and the 25(OH)D3:24,25(OH)2D3 ratio were not associated with any cardiovascular outcome (all P  > .05). Conclusions Changes in 3-epi-25(OH)D3 levels may regulate cardiovascular functional capacity in patients with advanced CKD. [ABSTRACT FROM AUTHOR]

(1) Background: Cardiovascular disease is one of the leading causes of mortality after liver transplantation. Body composition and cardiovascular performance assessment represent a potential approach for modulating lifestyle correction and proper follow-up in chronic disease patients. This study aimed to verify the additional role of an unsupervised physical activity program in a sample of male liver transplant recipients who follow the Mediterranean diet. (2) Methods: Thirty-three male liver transplant recipients were enrolled. Sixteen subjects followed a moderate-intensity home exercise program in addition to nutritional support, and seventeen received advice on the Mediterranean diet. After six months, bioelectrical vector impedance analysis (BIVA) and cardiopulmonary exercise testing (CPET) were performed. (3) Results: No differences in CPET (VO2 peak: exercise 21.4 ± 4.1 vs. diet 23.5 ± 6.5 mL/kg/min; p = 0.283) and BIVA (Z/H: exercise 288.3 ± 33.9 vs. diet 310.5 ± 34.2 Ω/m; p = 0.071) were found. Furthermore, the BIVA values of resistance correlate with the submaximal performance of the Ve/VCO2 slope (R = 0.509; p < 0.05) and phase angle with the maximal effort of the VO2 peak (R = 0.557; p < 0.05). (4) Conclusions: Unsupervised physical exercise alone for six months does not substantially modify liver transplant recipients' cardiovascular performance and hydration status, despite their adherence to a Mediterranean diet. The body composition analysis is useful to stratify the risk profile, and it is potentially associated with better outcomes in transplanted subjects. [ABSTRACT FROM AUTHOR]

Aim: Effort intolerance is frequent in patients with overweight/obesity and/or type 2 diabetes (T2D) free from cardiac and respiratory disease. We sought to quantify the independent effects of T2D and body mass index (BMI) on cardiopulmonary capacity and gain insights on the possible pathophysiology by case‐control and regression analyses. Methods: Patients at high/moderate cardiovascular risk, with or without T2D, underwent spirometry and combined echocardiography‐cardiopulmonary exercise test as part of their clinical workup. Subjects with evidence of cardiopulmonary disease were excluded. The effects of T2D and obesity were estimated by multivariable models accounting for known/potential confounders and the major pathophysiological determinants of oxygen uptake at peak exercise (VO2peak) normalized for fat‐free mass (FFM). Results: In total, 109 patients with T2D and 97 controls were included in the analysis. The two groups had similar demographic and anthropometric characteristics except for higher BMI in T2D (28.6 ± 4.6 vs. 26.3 ± 4.4 kg/m2, p =.0003) but comparable FFM. Patients with T2D achieved lower VO2peak than controls (18.5 ± 4.4 vs. 21.7 ± 8.3 ml/min/kg, p =.0006). Subclinical cardiovascular dysfunctions were observed in T2D: concentric left ventricular remodelling, autonomic dysfunction, systolic dysfunction and reduced systolic reserve. After accounting for confounders and major determinants of VO2peakFFM, T2D still displayed reduced VO2peak by 1.0 (−1.7/−0.3) ml/min/kgFFM, p =.0089, while the effect of BMI [−0.2 (−0.3/0.1) ml/min/kgFFM, p =.06 per unit increase], was largely explained by a combination of chronotropic incompetence, reduced peripheral oxygen extraction, impaired systolic reserve and ventilatory (in)efficiency. Conclusions: T2D is an independent negative determinant of VO2peak whose effect is additive to other pathophysiological determinants of oxygen uptake, including BMI. [ABSTRACT FROM AUTHOR]

Abstract A 64‐year‐old obese gentleman attended for further evaluation of ongoing dyspnoea in the context of a previous diagnosis of moderate COPD treated with dual long‐acting bronchodilators. A cardiopulmonary exercise test (CPET) was performed, which demonstrated reduced peak work and oxygen consumption with evidence of dynamic hyperinflation, abnormal gas exchange and ventilatory limitation despite cardiac reserve. The CPET clarified the physiological process underpinning the patient's dyspnoea and limiting the patient's activities. This, in turn, helped the clinician tailor the patient's management plan.

Activation of small molecules such as CO2, N2 or organic substrates and their subsequent transformation into complex value-added chemicals by electrocatalysis, utilizing renewable energy sources under ambientconditions, has gained considerable interest in the last few years. However, activation of these chemically inertmolecules is hindered by their intrinsically high activation energy barrier presupposing the development of tailored catalytic systems, often precluding selective transformation to the desired target products. Recent studies have shown that the utilization of concerted proton-electron transfer (CPET) mediators (med-H) may facilitate these challenging electrocatalytic reactions.

A 64‐year‐old obese gentleman attended for further evaluation of ongoing dyspnoea in the context of a previous diagnosis of moderate COPD treated with dual long‐acting bronchodilators. A cardiopulmonary exercise test (CPET) was performed, which demonstrated reduced peak work and oxygen consumption with evidence of dynamic hyperinflation, abnormal gas exchange and ventilatory limitation despite cardiac reserve. The CPET clarified the physiological process underpinning the patient's dyspnoea and limiting the patient's activities. This, in turn, helped the clinician tailor the patient's management plan. [ABSTRACT FROM AUTHOR]

Heart failure is a common phenomenon in congenital heart disease patients. Cardiopulmonary exercise testing is used for a reliable assessment of heart failure but is still challenging, especially for young children. Implementing mobile cardiopulmonary exercise testing (CPET) can close that diagnostic gap. While average values for healthy children have already been published, this study aims to describe typical ranges of cardiovascular performance parameters of young children with congenital heart disease performing an 8-min running cardiopulmonary exercise test. Children aged 4–8 years with common congenital heart defects after corrective surgery (Tetralogy of Fallot; transposition of the great arteries and univentricular hearts after palliation) were included. The outdoor running protocol consisted of slow walking, slow jogging, fast jogging, and maximum speed running. Each exercise was performed for 2 min, except the last, in which children were instructed to keep up maximal speed as long as possible. A total of 78 children (45 male/33 female, mean age 6,24) with congenital heart disease participated in the study, of which 97% completed the CPET successfully. A detailed description of participating patients, including data on cardiac function and subjective fitness levels, is given to help physicians use this method to classify their patients. This study presents a typical range for cardiovascular performance parameters in a population of 4–8-year-old children with congenital heart disease tested in a newly developed outdoor running protocol for CPET. [ABSTRACT FROM AUTHOR]

Aerobic, or endurance, exercise is an energy requiring process supported primarily by energy from oxidative adenosine triphosphate synthesis. The consumption of oxygen and production of carbon dioxide in muscle cells are dynamically linked to oxygen uptake (V̇O 2) and carbon dioxide output (V̇CO 2) at the lung by integrated functions of cardiovascular, pulmonary, hematologic, and neurohumoral systems. Maximum oxygen uptake (V̇O 2max) is the standard expression of aerobic capacity and a predictor of outcomes in diverse populations. While commonly limited in young fit individuals by the capacity to deliver oxygen to exercising muscle, (V̇O 2max) may become limited by impairment within any of the multiple systems supporting cellular or atmospheric gas exchange. In the range of available power outputs, endurance exercise can be partitioned into different intensity domains representing distinct metabolic profiles and tolerances for sustained activity. Estimates of both V̇O 2max and the lactate threshold, which marks the upper limit of moderate-intensity exercise, can be determined from measures of gas exchange from respired breath during whole-body exercise. Cardiopulmonary exercise testing (CPET) includes measurement of V̇O 2 and V̇CO 2 along with heart rate and other variables reflecting cardiac and pulmonary responses to exercise. Clinical CPET is conducted for persons with known medical conditions to quantify impairment, contribute to prognostic assessments, and help discriminate among proximal causes of symptoms or limitations for an individual. CPET is also conducted in persons without known disease as part of the diagnostic evaluation of unexplained symptoms. Although CPET quantifies a limited sample of the complex functions and interactions underlying exercise performance, both its specific and global findings are uniquely valuable. Some specific findings can aid in individualized diagnosis and treatment decisions. At the same time, CPET provides a holistic summary of an individual's exercise function, including effects not only of the primary diagnosis, but also of secondary and coexisting conditions. [ABSTRACT FROM AUTHOR]

Stringer et al. [J Appl Physiol (1985) 82: 908-912, 1997] developed a method from invasive data to estimate cardiac output during incremental exercise testing based on Fick's principle. The authors proposed that the arterio-mixed venous oxygen content difference increases linearly with percentage of maximal O2 consumption. We hypothesized an S-shaped pattern in the published data and calculated the inflection point of this curve and of the standard resting oxygen dissociation curve. Using a partial F test, we compared the linear model with a third-order polynomial model, which showed a better fit to the data [F(2,101) = 9.5, P < 0.001]. This finding was reproduced in a dataset published by Åstrand et al. in 1964 [F(2, 122) = 10.6, P < 0.001]. The inflection point of the curve coincided with the lactate acidosis threshold [first ventilatory threshold (VT1)] as measured by Stringer et al. (VT1 at 50% and inflection point at 56% [95% CI, 52.9 to 60.7] of maximal O2 consumption). The inflection point of the standard resting oxygen dissociation curve was calculated at a partial pressure of 21.5 mmHg and a saturation of 36%, matching the "critical capillary PO2" concept of Stringer et al. (21.2 mmHg). We conclude that the arterio-mixed venous oxygen content difference increases in an S-shaped manner with percentage of maximal oxygen consumption and that the inflection point of this curve may correspond to VT1 and that of the in vivo oxygen dissociation curve. Further research is needed to confirm these findings and improve the method. [ABSTRACT FROM AUTHOR]

Background: Lower fitness is a predictor of adverse outcomes after radical cystectomy. Lockdown measures during the COVID-19 pandemic affected daily physical activity. We hypothesised that lockdown during the pandemic was associated with a reduction in preoperative aerobic fitness and an increase in postoperative complications in patients undergoing radical cystectomy. Methods: We reviewed routine preoperative cardiopulmonary exercise testing (CPET) data collected prior to the pandemic (September 2018 to March 2020) and after lockdown (March 2020 to July 2021) in patients undergoing radical cystectomy. Differences in CPET variables, Postoperative Morbidity Survey (POMS) data, and length of hospital stay were compared. Results: We identified 267 patients (85 pre-lockdown and 83 during lockdown) who underwent CPET and radical cystectomy. Patients undergoing radical cystectomy throughout lockdown had lower ventilatory anaerobic threshold (9.0 [7.9–10.9] vs 10.3 [9.1–12.3] ml kg−1 min−1; P=0.0002), peak oxygen uptake (15.5 [12.9–19.1] vs 17.5 [14.4–21.0] ml kg−1 min−1; P=0.015), and higher ventilatory equivalents for carbon dioxide (34.7 [31.4–38.5] vs 33.4 [30.5–36.5]; P=0.030) compared with pre-lockdown. Changes were more pronounced in males and those aged >65 yr. Patients undergoing radical cystectomy throughout lockdown had a higher proportion of day 5 POMS-defined morbidity (89% vs 75%, odds ratio [OR] 2.698, 95% confidence interval [CI] 1.143–6.653; P=0.019), specifically related to pulmonary complications (30% vs 13%, OR 2.900, 95% CI 1.368–6.194; P=0.007) and pain (27% vs 9%, OR 3.471, 95% CI 1.427–7.960; P=0.004), compared with pre-lockdown on univariate analysis. Conclusions: Lockdown measures in response to the COVID-19 pandemic were associated with a reduction in fitness and an increase in postoperative morbidity among patients undergoing radical cystectomy.

Abstract Studies using cardiopulmonary exercise testing (CPET) to evaluate persistent dyspnea following infection with COVID‐19 have focused on older patients with co‐morbid diseases who are post‐hospitalization. Less attention has been given to younger patients with post‐COVID‐19 dyspnea treated as outpatients for their acute infection. We sought to determine causes of persistent dyspnea in younger patients recovering from acute COVID‐19 infection that did not require hospitalization. We collected data on all post‐COVID‐19 patients who underwent CPET in our clinic in the calendar year 2021. Data on cardiac function and respiratory response were abstracted, and diagnoses were assigned using established criteria. CPET data on 45 patients (238.3 ± 124 days post‐test positivity) with a median age of 27.0 (22.0–40.0) were available for analysis. All but two (95.6%) were active‐duty service members. The group showed substantial loss of aerobic capacity—average VO2 peak (L/min) was 84.2 ± 23% predicted and 25 (55.2%) were below the threshold for normal. Spirometry, diffusion capacity, high‐resolution computed tomography, and echocardiogram were largely normal and were not correlated with VO2peak. The two most common contributors to dyspnea and exercise limitation following comprehensive evaluation were deconditioning and dysfunctional breathing (DB). Younger active‐duty military patients with persistent dyspnea following outpatient COVID‐19 infection show a substantial reduction in aerobic capacity that is not driven by structural cardiopulmonary disease. Deconditioning and DB breathing are common contributors to their exercise limitation. The chronicity and severity of symptoms accompanied by DB could be consistent with an underlying myopathy in some patients, a disorder that cannot be differentiated from deconditioning using non‐invasive CPET.

Abstract Background The clinical value of cardiopulmonary exercise testing (CPET) in cardiac amyloidosis (CA) is uncertain. Due to the growing prevalence of the disease and the current availability of disease‐modifying drugs, prognostic stratification is becoming fundamental to optimizing the cost‐effectiveness of treatment, patient phenotyping, follow‐up, and management. Peak VO2 and VE/VCO2 slope are currently the most studied CPET variables in clinical settings, and both demonstrate substantial, independent prognostic value in several cardiovascular diseases. We aim to study the association of peak VO2 and VE/VCO2 slope with prognosis in patients with CA. Methods and results We performed a systematic review and searched for clinical studies performing CPET for prognostication in patients with transthyretin‐CA and light‐chain‐CA. Studies reporting hazard ratio (HR) for mortality and peak VO2 or VE/VCO2 slope were further selected for quantitative analysis. HRs were pooled using a random‐effect model. Five studies were selected for qualitative and three for quantitative analysis. A total of 233 patients were included in the meta‐analysis. Mean peak VO2 resulted consistently depressed, and VE/VCO2 slope was increased. Our pooled analysis showed peak VO2 (pooled HR 0.89, 95% CI 0.84–0.94) and VE/VCO2 slope (pooled HR 1.04, 95% CI 1.01–1.07) were significantly associated with the risk of death in CA patients, with no significant statistical heterogeneity for both analyses. Conclusions CPET is a valuable tool for prognostic stratification in CA, identifying patients at increased risk of death. Large prospective clinical trials are needed to confirm this exploratory finding.

Abstract Background Anemia is associated with impaired physical performance and adverse perioperative outcomes. Iron-deficiency anemia is increasingly treated with intravenous iron before elective surgery. We explored the relationship between exercise capacity, anemia, and total hemoglobin mass (tHb-mass) and the response to intravenous iron in anemic patients prior to surgery. Methods A prospective clinical study was undertaken in patients having routine cardiopulmonary exercise testing (CPET) with a hemoglobin concentration ([Hb])

Background: Exercise training in patients with HCM has evidenced benefits on functional capacity, cardiac function, and a reversion of adverse cardiac remodeling. The objective of this study was to assess the effect of a concurrent resistance and cardiorespiratory training program on functional capacity, biochemical parameters, and echocardiographic variables in a pilot group. Methods: Two HCM patients were evaluated before and after 12 weeks of individualized concurrent training with two sessions/week. Pre- and post-training data were compared for each patient. Evaluations included a cardiopulmonary exercise test (CPET), body composition, echocardiography, electrocardiography, and blood analysis. Results: Training promoted an increase in functional capacity (+4 mL·kg−1·min−1), ventilatory thresholds, and other CPET-derived variables associated with a better prognosis and long-term survival. Muscular mass was augmented (0.8 and 1.2 kg), along with a mean increase of 62% in upper and lower body strength. Echocardiographic features demonstrated the maintenance of cardiac function with signs of positive left ventricular remodeling and an improvement in diastolic function. Blood analyses, including cardiac troponins and NT-proBNP, displayed uneven changes in each patient, but the values fell into normal ranges in both cases. Conclusions: The available data suggest a positive effect of concurrent resistance and cardiorespiratory training on patients’ functional capacity and cardiac function that may improve their functional class, quality of life, and long-term prognosis. The replication of this protocol in a larger cohort of patients is warranted to confirm these preliminary results.

A 48-year-old woman who had been receiving long-term interferon-β for 8 years for multiple sclerosis developed drug-induced World Health Organization group I pulmonary arterial hypertension. Triple therapy for pulmonary arterial hypertension and suspension of interferon-β led to improvement from a high-risk to low-risk state and improvement in exercise hemodynamics, including vascular distensibility, and right ventricle-pulmonary artery coupling. (Level of Difficulty: Advanced.).

Introduction: The diagnosis and severity assessment of COPD relies on spirometry, and in particular the FEV1. However, it has been proposed that hyperinflation and air-trapping are better predictors of exercise capacity and mortality than the FEV1. Research: question: Does static hyperinflation predict exercise capacity? Methods: We conducted an observational prospective study. Patients with COPD referred to the lung function laboratory were consecutively recruited. Patients with hyperinflation (the experimental group) were compared to patients without hyperinflation (the control group). The sample sizes were determined assuming an effect size of 0.5 and a power of 0.80. Results: We recruited 124 participants, of whom 87% were male, the mean age was 66.1 ± 8.8 years. 67% were symptomatic (GOLD B or D). Airflow limitation was moderate to severe in the majority of patients (median FEV1 47%, IQR 38-65%) and 43% of patients had static hyperinflation. The median 6MWD was 479 meters (404-510) and peak workload in CPET was 64 watts (46-88) with peak VO2 1.12 L/min, 0.89-1.31 L/min. Patients with lower FEV1, DLCO and IC/TLC and higher RV/TLC had reduced exercise capacity in both 6MWT and CPET, measured as lower distance, greater desaturation and ∆Borg dyspnoea, and reduced workload, peak VO2 and peak VE and higher desaturation and ventilatory limitation (VE/MVV). An IC/TLC < 0.33 predicted reduced exercise performance (peak O2

Limitation in exercise capacity has not been described in athletes affected by SARS‐CoV‐2 infection. However, patients who have recovered from COVID‐19 without cardiopulmonary impairment show exaggerated ventilatory response during exercise. Therefore, we aimed to evaluate the ventilatory efficiency (VEf) in competitive athletes recovered from COVID‐19 and to characterize the ventilation versus carbon dioxide relationship (VE/VCO2) slope in this population. Thirty‐seven competitive athletes with COVID‐19 were recruited for this study. All participants underwent spirometry, echocardiography, and cardiopulmonary exercise testing (CPET). z‐FVC values and end‐title pressure of CO2 (PETCO2) were lower in the third tertile compared with the first tertile: −0.753 ± 0.473 vs. 0.037 ± 0.911, p = 0.05; 42.2 ± 2.7 vs. 37.1 ± 2.5 mmHg, p < 0.01. VE/VCO2 slope was significantly correlated to maximal VCO2/VE and maximal VO2/VE: coefficient = −0.5 R2 = 0.58, p < 0.0001 and coefficient = −0.3 R2 = 0.16, p = 0.008. Competitive athletes affected by SARS‐CoV‐2 infection, without cardio‐respiratory disease sequel, may present ventilatory inefficiency (ViE), without exercise capacity limitation. FVC is higher in athletes with better ventilatory performance during exercise, and increased VE/VCO2 slope is inversely correlated to max VCO2/VE and max VO2/VE. [ABSTRACT FROM AUTHOR]

Postacute sequelae of SARS-CoV-2 (PASC) is a long-term consequence of acute infection from COVID-19. Clinical overlap between PASC and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has been observed, with shared symptoms including intractable fatigue, postexertional malaise, and orthostatic intolerance. The mechanistic underpinnings of such symptoms are poorly understood. Early studies suggest deconditioning as the primary explanation for exertional intolerance in PASC. Cardiopulmonary exercise testing reveals perturbations related to systemic blood flow and ventilatory control associated with acute exercise intolerance in PASC, which are not typical of simple detraining. Hemodynamic and gas exchange derangements in PASC have substantial overlap with those observed with ME/CFS, suggestive of shared mechanisms. This review illustrates exercise pathophysiologic commonalities between PASC and ME/CFS that will help guide future diagnostics and treatment. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: The clinical value of cardiopulmonary exercise testing (CPET) in cardiac amyloidosis (CA) is uncertain. Due to the growing prevalence of the disease and the current availability of disease‐modifying drugs, prognostic stratification is becoming fundamental to optimizing the cost‐effectiveness of treatment, patient phenotyping, follow‐up, and management. Peak VO2 and VE/VCO2 slope are currently the most studied CPET variables in clinical settings, and both demonstrate substantial, independent prognostic value in several cardiovascular diseases. We aim to study the association of peak VO2 and VE/VCO2 slope with prognosis in patients with CA. Methods and results: We performed a systematic review and searched for clinical studies performing CPET for prognostication in patients with transthyretin‐CA and light‐chain‐CA. Studies reporting hazard ratio (HR) for mortality and peak VO2 or VE/VCO2 slope were further selected for quantitative analysis. HRs were pooled using a random‐effect model. Five studies were selected for qualitative and three for quantitative analysis. A total of 233 patients were included in the meta‐analysis. Mean peak VO2 resulted consistently depressed, and VE/VCO2 slope was increased. Our pooled analysis showed peak VO2 (pooled HR 0.89, 95% CI 0.84–0.94) and VE/VCO2 slope (pooled HR 1.04, 95% CI 1.01–1.07) were significantly associated with the risk of death in CA patients, with no significant statistical heterogeneity for both analyses. Conclusions: CPET is a valuable tool for prognostic stratification in CA, identifying patients at increased risk of death. Large prospective clinical trials are needed to confirm this exploratory finding. [ABSTRACT FROM AUTHOR]

BackgroundIt has not yet been conclusively determined whether reduced left ventricular global longitudinal strain (LV GLS) after COVID-19 contributes to a reduction in exercise capacity. Our own studies showed a possible mild myocardial involvement in the form of reduced LV GLS in athletes after COVID-19 compared with healthy athletes. The aims of this prospective follow-up study were to investigate the development of LV GLS over a 3-month period in athletes after COVID-19 and the possible relationship between LV GLS and physical performance.MethodsLV GLS was determined in four-, two-, and three-chamber views and assessed offline by a blinded investigator in 96 recreational athletes (mean age 33.15 ± 12.40 years, 53 male, peak VO2 38.82 ± 11.14 ml/min/kg) at a median of two (t0) and five months (t1) after COVID-19. Cardiopulmonary exercise testing (CPET) was performed on a bicycle ergometer on both examination dates.ResultsLV GLS improved significantly between t0 and t1 (t0 −18.82 ± 2.02 vs. t1 −19.46 ± 2.05, p

Background: Anemia is associated with impaired physical performance and adverse perioperative outcomes. Iron-deficiency anemia is increasingly treated with intravenous iron before elective surgery. We explored the relationship between exercise capacity, anemia, and total hemoglobin mass (tHb-mass) and the response to intravenous iron in anemic patients prior to surgery. Methods: A prospective clinical study was undertaken in patients having routine cardiopulmonary exercise testing (CPET) with a hemoglobin concentration ([Hb]) < 130 g.l−1 and iron deficiency/depletion. Patients underwent CPET and tHb-mass measurements before and a minimum of 14 days after receiving intravenous (i.v.) Ferric derisomaltose (Monofer®) at the baseline visit. Comparative analysis of hematological and CPET variables was performed pre and post-iron treatment. Results: Twenty-six subjects were recruited, of whom 6 withdrew prior to study completion. The remaining 20 (9 [45%] male; mean ± SD age 68 ± 10 years) were assessed 25 ± 7 days between baseline and the final visit. Following i.v. iron, increases were seen in [Hb] (mean ± SD) from 109 ± 14 to 116 ± 12 g l−1 (mean rise 6.4% or 7.3 g l−1, p = < 0.0001, 95% CI 4.5–10.1); tHb-mass from 497 ± 134 to 546 ± 139 g (mean rise 9.3% or 49 g, p = < 0.0001, 95% CI 29.4–69.2). Oxygen consumption at anerobic threshold ( V ˙ O2 AT) did not change (9.1 ± 1.7 to 9.8 ± 2.5 ml kg−1 min−1, p = 0.09, 95% CI − 0.13 − 1.3). Peak oxygen consumption ( V ˙ O2 peak) increased from 15.2 ± 4.1 to 16 ± 4.4 ml.kg.−1 min−1, p = 0.02, 95% CI 0.2–1.8) and peak work rate increased from 93 [67–112] watts to 96 [68–122] watts (p = 0.02, 95% CI 1.3–10.8). Conclusion: Preoperative administration of intravenous iron to iron-deficient/deplete anemic patients is associated with increases in [Hb], tHb-mass, peak oxygen consumption, and peak work rate. Further appropriately powered prospective studies are required to ascertain whether improvements in tHb-mass and performance in turn lead to reductions in perioperative morbidity. Trial registration: ClinicalTrials.gov identifier: NCT 033 46213. [ABSTRACT FROM AUTHOR]

(1) Background: Cardiovascular disease is one of the leading causes of mortality after liver transplantation. Body composition and cardiovascular performance assessment represent a potential approach for modulating lifestyle correction and proper follow-up in chronic disease patients. This study aimed to verify the additional role of an unsupervised physical activity program in a sample of male liver transplant recipients who follow the Mediterranean diet. (2) Methods: Thirty-three male liver transplant recipients were enrolled. Sixteen subjects followed a moderate-intensity home exercise program in addition to nutritional support, and seventeen received advice on the Mediterranean diet. After six months, bioelectrical vector impedance analysis (BIVA) and cardiopulmonary exercise testing (CPET) were performed. (3) Results: No differences in CPET (VO2 peak: exercise 21.4 ± 4.1 vs. diet 23.5 ± 6.5 mL/kg/min; p = 0.283) and BIVA (Z/H: exercise 288.3 ± 33.9 vs. diet 310.5 ± 34.2 Ω/m; p = 0.071) were found. Furthermore, the BIVA values of resistance correlate with the submaximal performance of the Ve/VCO2 slope (R = 0.509; p < 0.05) and phase angle with the maximal effort of the VO2 peak (R = 0.557; p < 0.05). (4) Conclusions: Unsupervised physical exercise alone for six months does not substantially modify liver transplant recipients’ cardiovascular performance and hydration status, despite their adherence to a Mediterranean diet. The body composition analysis is useful to stratify the risk profile, and it is potentially associated with better outcomes in transplanted subjects.

Abstract Limitation in exercise capacity has not been described in athletes affected by SARS‐CoV‐2 infection. However, patients who have recovered from COVID‐19 without cardiopulmonary impairment show exaggerated ventilatory response during exercise. Therefore, we aimed to evaluate the ventilatory efficiency (VEf) in competitive athletes recovered from COVID‐19 and to characterize the ventilation versus carbon dioxide relationship (VE/VCO2) slope in this population. Thirty‐seven competitive athletes with COVID‐19 were recruited for this study. All participants underwent spirometry, echocardiography, and cardiopulmonary exercise testing (CPET). z‐FVC values and end‐title pressure of CO2 (PETCO2) were lower in the third tertile compared with the first tertile: −0.753 ± 0.473 vs. 0.037 ± 0.911, p = 0.05; 42.2 ± 2.7 vs. 37.1 ± 2.5 mmHg, p

Purpose: Assess safety and feasibility of the cardiopulmonary exercise test (CPET) for evaluating head and neck cancer (HaNC) survivors. Also compare their cardiorespiratory fitness to age and sex‐matched norms and establish current physical activity levels. Methods: Fifty HaNC survivors [29 male; mean (SD) age, 62 (8) years], who had completed treatment up to 1 year previously, were recruited. Participants performed a CPET on a cycle ergometer to symptom‐limited tolerance. Participants completed a questionnaire to report contributory factors they perceived as influencing test termination. Physical activity levels were determined using a self‐reported physical activity questionnaire. Results: Three participants did not complete the CPET because (1) poor fitting mouthpiece and naso‐oral mask due to facial disfiguration from surgery; (2) knee pain elicited by cycling; and (3) early CPET termination due to electrocardiogram artefacts. Participants reached a mean peak oxygen uptake that was 34% lower than predicted and the mean (SD) CPET duration of 7:52 (2:29) min:s was significantly lower than the target test duration of 10 min (p < 0.001). Leg muscle aches and/or breathing discomfort were major contributory factors influencing test termination for 78% of participants, compared to 13% for dry mouth/throat and/or drainage in the mouth/throat. No major adverse events occurred. Participants were categorised as 26% active, 8% moderately active, and 66% insufficiently active. Conclusion: These preliminary data suggest the CPET appears safe and feasible for most HaNC survivors when strict exclusion criteria are applied; however, low levels of cardiorespiratory fitness should be considered when calculating an appropriate ramp rate. [ABSTRACT FROM AUTHOR]

Sacubitril/valsartan (Sac/Val) reduces mortality in patients with heart failure with reduced ejection fraction (HFrEF) compared to enalapril. However, its effects on functional capacity remain uncertain; consequently, we sought to compare Sac/Val vs. standard medical therapy, in terms of effects on prognostically significant CPET parameters, in HFrEF patients during a long follow-up period. We conducted a single-center, observational study in an HF clinic; specifically, we retrospectively identified that 12 patients switched to Sac/Val and 13 patients that managed with standard, optimal medical therapy (control group). At each visit, baseline, and follow-up (median time: 16 months; IQ range: 11.5–22), we collected demographic information, medical history, vital signs, cardiopulmonary exercise testing, standard laboratory data, pharmacological treatment information, and echocardiographic parameters. The study's primary end-point was the change from baseline in peak VO2 (adjusted to body weight). We did not observe significant differences between the two study groups at baseline. Similarly, we did not observe any significant differences during the follow-up in mean values of peak VO2 corrected for body weight: Sac/Val baseline: 12.2 ± 4.6 and FU: 12.7 ± 3.3 vs. control group: 13.1 ± 4.2 and 13.0 ± 4.2 mL/kg/min; p = 0.49. No significant treatment differences were observed for changes in VE/VCO2 slope: Sac/Val baseline: 35.4 ± 7.4 and FU: 37.2 ± 13.1 vs. control group: 34.6 ± 9.1 and 34.0 ± 7.3; p = 0.49. In conclusion, after a median follow-up period of 16 months, there was no significant benefit of Sac/Val on peak VO2 and other measures of CPET compared with standard optimal therapy in patients with HFrEF. [ABSTRACT FROM AUTHOR]

Cardiopulmonary exercise testing (CPET) was limited to peak oxygen consumption analysis (VO2peak), and now the ventilation/carbon dioxide production (VE/VCO2) slope is recognized as having independent prognostic value. Unlike VO2peak, 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. [ABSTRACT FROM AUTHOR]

Individuals with Myalgic Encephalomyelitis (ME) have shown altered physiological responses during maximum cardiopulmonary exercise testing. However, maximal testing is not representative of the everyday activities reported to cause or increase symptoms in ME, and is not accessible for those with severe or very severe illness. The aim of this study was to assess the feasibility and acceptability of a home-based testing protocol to measure physiological responses in ME to everyday activity. Researchers attended participants' homes to collect data and provide equipment for independent testing. Adults with ME who met the International Consensus Criteria wore a portable metabolic assessment system and a physiological stress monitor. Blood pressure, heart rate, oxygen saturation and lactic acid were assessed during a range of everyday positions and activities in their own homes. Online recruitment yielded 70 volunteers in 24 h. 17 eligible individuals reflecting a range of illness severities were enrolled. All participants found the procedures acceptable with 12 (70%) subjects completing every listed activity. Apparent physiological abnormalities were identified in all participants. Physiological measurement during everyday activities was feasible for our participants who represented a range of ME severities. Activities must be adapted for different levels of severity to avoid significant symptom exacerbation. Further research is needed to develop home-based assessment protocols to advance the biobehavioral understanding of ME. Trial registration number: ISRCTN78379409. [ABSTRACT FROM AUTHOR]