Assessment Of Exercise Capacity Research Articles

Abstract 4136159: Determinants of Exercise Intolerance in Postural Orthostatic Tachycardia Syndrome: a Systematic Review

Background: Postural Orthostatic Tachycardia Syndrome (POTS) is a syndrome of an exaggerated heart rate (HR) response with standing, disproportionately affecting young women associated with exercise intolerance due to dizziness, palpitations, and/or chest pain. Research question: How does the exaggerated increase in HR with standing translate into impaired exercise tolerance in subjects with POTS? Aims: To systematically analyze determinants of exercise intolerance in subjects with POTS. Methods: We searched the National Library of Science and identifed 11 cohorts with a diagnosis of POTS and an assessment of exercise capacity. We abstracted the information including type of exercise testing, hemodynamics and gas exchange parameters (peak oxygen consumption [VO 2 ]) with exercise, and effect of interventions (if present). Results: We identified 849 subjects with POTS, female:male ratio of 8.5:1, 25±8 years, and 365 age-and sex-matched controls. A cycle ergometer was used in 8 studies (574 subjects, 68%) and a treadmill in 3 (275 subjects, 32%). Peak VO 2 was measured in 10 studies (836 subjects, 98%), and exercise hemodynamics in 9 (593 subjects, 70%). All 11 (100%) studies described a higher HR at rest and during submaximal exercise in subjects with POTS, with a similar slope of HR/load, and shorter time to peak HR. Of the 9 studies with hemodynamics, 6 (67%) reported a reduction in stroke volume (SV) with standing and with exercise, but only 1 (11%) documented a reduction in cardiac output (CO). Two studies (22%) enrolling teenagers showed a variable increase in SV and CO in POTS. Peak VO 2 was reduced in 8 (80%) studies when compared with predicted values, but only in 4 (40%) when compared with controls matched for deconditioning. Intravenous fluid administration in two studies did not affect HR, SV, CO or peak VO 2 . Exercise training in one study (19 subjects) and propranolol 20 mg in another study (11 subjects) led to improving peak VO 2 . Conclusions: An exaggerated HR response with standing and with exercise is a hallmark of POTS, a mechanism by which subjects reach a higher HR at lower workloads. While the increase in HR is associated with a reduction in SV, CO is typically maintained and occasionally increased, therefore making it an unlikely mechanism responsible for the peculiar exertional symptoms of POTS. Strategies that result in a reduction in HR may, on the other hand, translate in improved exercise capacity in subjects with POTS.

Abstract 4146301: Relationship Between Calf Muscle Pump Function and Exercise Stress Testing

Background: Exercise stress testing uses metabolic equivalents of tasks (METs) to measure the energy cost of activities, aiding in the assessment of exercise capacity and cardiovascular health. Despite its significance, the correlation between calf muscle pump function (CPF) and exercise stress testing remains unexplored. We aimed to evaluate the relationship between CPF and peak METs as determined by cardiopulmonary treadmill exercise stress testing. Methods: The study included adults who underwent exercise cardiopulmonary stress testing and venous plethysmography at Mayo Clinic between April 2017 and March 2020. The protocols other than Bruce, Mayo, Modified Naughton, and Naughton protocols were excluded. The CPF ejection fraction (EF) was calculated per leg based on refill volumes post-exercise as a percentage of passive drain refill. The classification of CEAP (Clinical-Etiology-Anatomy-Pathophysiology) was utilized to better understand chronic venous insufficiency (CVI). Results: A total of 155 patients who underwent both exercise stress testing and venous plethysmography were included, with a mean age of 61.31 ± 14.03 years, and 84 (54.2%) were male. The peak measured METs for normal, unilaterally reduced, and bilaterally reduced CPF were 8.5 (2.5), 7.3 (2.1), and 7.1 (2.4), respectively (p=0.004, Figure 1). Multiple linear regression models were developed with METs as the outcome to determine if CPF was an independent predictor of METs on cardiopulmonary exercise stress testing. IIn model 1, the following independent variables were included: resting heart rate, peak heart rate, peak systolic blood pressure, recovery heart rate at minute 1, and worst EF (Table 1). In model 1, with only exercise parameters, lower EF was associated with lower METs (p=0.03). In a second analysis, variables identified as statistically significant with METs in the initial model were included, along with CEAP class (model 2) and CCI (model 3) (Table 2). In model 2, CEAP class 3 or higher was associated with decreased METs on the exercise stress test. This correlation implies that individuals with moderate to severe CVI may influence exercise capacity, demonstrating the interconnectedness of the cardiovascular system. Moreover, in model 3, the CCI, a predictor for mortality, was not significantly associated with METs. Conclusion: Our findings revealed that more severe CVI (CEAP class and reduced CPF) was associated with reduced exercise capacity after accounting for other factors.

Averaged Oxygen Desaturation Improves the Prognostic Value of the Six-Minute Walk Test in Elderly Patients with Heart Failure.

Heart failure (HF) is a major cause of hospitalization, and exercise capacity is a key prognostic marker. The six-minute walk test (6MWT) is widely used to assess exercise capacity, but six-minute walk distance (6MWD) varies among individuals, especially the elderly. This study aimed to assess the hypothesis that ΔSpO₂-Ex, the average oxygen desaturation during the 6MWT, could enhance the prognostic value of 6MWD in elderly HF patients for cardiovascular risk prediction. In this single-center, prospective observational study, 55 patients aged ≥ 65 years with acute HF were evaluated before discharge. Patients were divided into small and large ΔSpO₂-Ex groups and short and long 6MWD groups based on cut-off values of 6.7% and 220 m, respectively, obtained from the Receiver Operating Characteristics curve analysis. Patients were followed for one year to assess major adverse cardiovascular events, including rehospitalization for heart failure or cardiovascular death. The mean ΔSpO₂-Ex was 5.8 ± 4.3%, and the mean 6MWD was 237.5 ± 106.7 m. Patients with large ΔSpO₂-Ex had significantly higher event rates (HR 6.66, p < 0.001), while those with short 6MWD had HR of 2.40 (p = 0.03). Combining ΔSpO₂-Ex with 6MWD improved predictive accuracy (AUC 0.78) compared to either marker alone (AUC 0.72 for ΔSpO₂-Ex and 0.62 for 6MWD). Importantly, patients with both large ΔSpO₂-Ex and short 6MWD had the highest event rates, indicating the additive prognostic value of combining both markers. ΔSpO₂-Ex is a complementary marker to 6MWD, improving risk stratification in elderly HF patients.

OPTIMISING EFFORT CAPACITY IN TRIATHLON

Background. My personal triathlon practice inspired the creation of a specialized training regimen to improve triathlon training in Romania. This program aims to enhance performance, well-being, and injury prevention for athletes. At the INTERDISCIPLINARY RESEARCH CENTRE (CCI) “Dr. Alexandru Partheniu” of UNEFS, we used AEROSCAN technology to assess exercise capacity, measuring heart and breathing rates with the Bruce Protocol for precise physiological monitoring. Objectives. This research demonstrates that tailored training cycles for swimming, cycling, and running can significantly enhance triathlon performance. The goal was to create a customizable, comprehensive training program to maximize the overall training process and provide a scientific foundation for triathlon training in Romania. This research aims to demonstrate that tailored training cycles can significantly enhance triathlon performance. Methods. We used observation, experimental, statistical-mathematical, and bibliographic study methods to interpret the experiment's outcomes. The bibliographic study provided the theoretical basis, while observation and experimental methods enabled real-time data collection. Statistical analysis was crucial for interpreting the data. Results. Using AEROSCAN and the Polar system, we evaluated exercise capacity and tracked heart rate. The Bruce protocol was applied for both initial and final tests. The data showed significant improvements in endurance, speed, and overall performance, supported by statistical analysis, after implementing the customized training program. Conclusion: Our research indicates that tailored athletic training regimens for each triathlon discipline can significantly enhance performance and promote athletes' health and longevity. The results highlight the importance of individualized training plans and suggest potential improvements in Romanian triathlon training practices. Individualized training programs lead to notable improvements in performance and athlete well-being.

Virtual pulmonary rehabilitation in Canada: A national survey of programs during the COVID-19 pandemic

Rationale Pandemic related restrictions resulted in a shift from in-person care to virtual care in pulmonary rehabilitation (PR) programs across Canada. The extent and effects of this transformation are understudied. Objectives This study aimed to characterize virtual pulmonary rehabilitation (VPR) in Canada and summarize implementation changes since the pandemic. Methods A national, cross-sectional, self-administered electronic survey was conducted between September and December 2023. Programs were identified through the public domain and national and provincial respiratory associations. Main Results A total of 184 PR program representatives were contacted: 114 were eligible to participate in the survey; of which 70 individuals representing 65 unique programs responded to the survey. A total of 71% of programs reported offering virtual care for PR assessment and/or treatment. More than 75% of programs used a hybrid approach for PR (eg, a combination of virtual and in-person care). Few programs used virtual care for pre/post assessments of exercise capacity and functional strength. Considerations for VPR included: assessing patient eligibility, emergency planning, implementation barriers and key resources. In the future, 69% of programs anticipated offering VPR, primarily using hybrid models of care. Conclusions This survey provides insight into virtual care used by programs across Canada during the pandemic, highlighting considerations and plans for PR delivery in the future.

Assessment of cardiopulmonary exercise capacity in suspected heart failure with preserved ejection fraction: impact of coronary flow velocity reserve and body fat

Abstract Background and objectives Heart failure with preserved ejection fraction (HFpEF) has various pathophysiology including coronary microvascular dysfunction (CMD), obesity, and frailty. In the present study, we aimed to assess the cardiopulmonary exercise capacity according to coronary microvascular function and body composition in patients with suspected HFpEF. Methods Patients with chest symptoms with non-obstructive coronary artery disease (&amp;lt;50% stenosis) and preserved left ventricle (LV) ejection fraction (≥50%) were enrolled. LV end-diastolic pressure was measured during coronary angiography. All patients underwent body composition analysis, adenosine stress echocardiography with the evaluation of coronary blood flow, and cardiopulmonary exercise test assessing maximal oxygen consumption (VO2max). Coronary flow velocity reserve (CFvR) was defined as the ratio of peak to baseline mean diastolic velocity of coronary blood flow. Association between VO2max and CFvR as well as body composition was assessed. Results Of the 106 patients (mean age 63.5), 54 (50.9%) were women, 52.4% had hypertension, and 28.6% had diabetes. Baseline LV end-diastolic pressure was 15.3 ± 5.5 mmHg. Median Heart Failure Association-PEFF score was 3, while medial e’ velocity was 6.7 ± 2.0 cm/s and E/e’ was 9.6 (7.6 – 12.0). Mean diastolic velocity of coronary blood flow was 0.17 [interquartile range (IQR) 0.13 – 0.23] m/sec at baseline, while it increased to 0.46 [IQR 0.38 – 0.57] m/sec at peak, resulting in CFvR of 2.75 [IQR 2.10 – 3.67]. Eighteen (17.1%) patients had CMD (CFvR &amp;lt;2.0). VO2max was 23.1 ± 5.4 mL/kg/min with lower value in women (21.7 ± 4.8 vs. 24.5 ± 5.6 mL/kg/min, p = 0.007). CFvR was directly related to VO2max (r = 0.350, p &amp;lt;0.001). In body composition, skeletal muscle mass index, percent body fat, and visceral fat area were associated with VO2max. In multivariable analysis, age, visceral fat area or percent body fat, and CFvR were linearly correlated with VO2max, and estimated VO2max was well correlated with measured VO2max. Conclusions Cardiopulmonary exercise capacity represented by VO2max was correlated with CFvR and body composition including skeletal muscle mass index, percent body fat, and visceral fat area in patients with suspected HFpEF. VO2max could be estimated by CFvR and fat component in the body.

Nutrition and Physical Activity in Older Adults with CKD patients: Two Sides of the Same Coin.

Nutrition and physical activity are two major issues in the management of CKD patients who are often older, have comorbidities and are prone to malnutrition and physical inactivity, conditions that cause loss of quality of life and increase the risk of death. We performed a multidimensional assessment of nutritional status and of physical performance and activity in CKD patients on conservative therapy in order to assess the prevalence of sedentary behaviour and its relationship with body composition. 115 consecutive stable CKD patients aged 45-80 years were included in the study. They had no major skeletal, muscular or neurological disabilities. All patients underwent a multidimensional assessment of body composition, physical activity and exercise capacity. Sedentary patients, as defined by mean daily METs &lt; 1.5 were older and differed from non-sedentary patients in terms of body composition, exercise capacity and nutrient intake, even after adjusting for age. Average daily METs were positively associated with lean body mass, muscle strength, 6-MWT performance, but negatively associated with fat body mass, body mass index and waist circumference. In addition, a sedentary lifestyle may have negative effects on free fat mass, muscle strength and exercise capacity, and may increase fat body mass. Conversely, s decrease in muscle mass and/or an increase in fat mass may lead to a decrease in physical activity and exercise capacity. There is a clear association and potential interrelationship between nutritional aspects and exercise capacity in older adults with CKD: they are really the two sides of the same coin.

Exercise testing in patients with tricuspid regurgitation undergoing transcatheter tricuspid valve intervention.

Transcatheter tricuspid valve intervention (TTVI) has shown promising results with persistent reduction of tricuspid regurgitation (TR) and improvements in functional class and quality of life (QOL). To analyze the impact of TTVI on maximal and submaximal exercise capacity (SEC). Constant work-rate exercise-time (CWRET) testing reflects SEC, which is more likely to be relevant for daily life activities and provides more differentiated physiological insight into the nature of exercise intolerance. Thus, 30 patients undergoing TTVI (21 direct annuloplasty and 9 edge-to-edge repair) received cardiopulmonary exercise testing (CPET) and CWRET (at 75% of maximum work rate in the initial CPET) before and 3months after TTVI. Patients' age was 80.5 [74.8-82.3] years and 53.3% were female. TR reduction ≥ 2 grades was achieved in 93.3% (TR grade ≤ moderate in 83.3%). Echocardiography revealed improved right ventricular (RV) characteristics with decreased RV basal diameter (47.0mm [43.0-54.3] vs. 41.5mm [36.8-48.0]; p < 0.001) and decreased inferior caval vein diameter. CWRET testing showed a significantly improved SEC (246.5s [153.8-416.8] vs. 338.5s [238.8-611.8] p = 0.001). Maximum oxygen uptake showed a positive trend without statistically significant differences (9.9ml/min/kg [8.6-12.4] vs. 11.7ml/min/kg [9.7-13.3]; p = 0.31). In contrast to the six-minute-walking distance (6MWD), SEC correlated moderately with effective regurgitation orifice area reduction (r = 0.385; p = 0.036), increased cardiac output (r = 0.378; p = 0.039), and improved QOL (r = 387; p = 0.035). Improvements in exercise capacity after TTVI mainly occur in the submaximal rather than in the maximal exercise range and correlate with hemodynamic effects and QOL. This may have a methodological impact on assessment of exercise capacity in these patients.

Use of the ECG-Controlled Six-Minute Walk Test to Assess Exercise Capacity: a Comparative Cohort Study

INTRODUCTION. In clinical practice, stress tests are carried out to draw up an individual patient rehabilitation plan, assess tolerance and optimize the load, and evaluate its clinical effectiveness. The Six-minute walk test (6MWT), in the presence of contraindications to the bicycle ergometer test or the impossibility of performing it, is a tool for assessing the response of the cardiovascular and respiratory systems to the load being performed. There is no description in the literature of the relationship between the distance traveled during 6MWT and the peak metabolic equivalent (MET) assessed during the bicycle ergometer test. AIM. Study the relationship between 6MWT indicators and the results of bicycle ergometer test in patients who have suffered a myocardial infarction. MATERIALS AND METHODS. During the examination, 56 patients underwent a symptom limited bicycle ergometer test and 6MWT, the peak MET and the distance traveled during 6MWT, as well as changes in the ECG during both tests were assessed. RESULTS AND DISCUSSION. The average values of maximum heart rate during the bicycle ergometer test and ECG-controlled 6MWT did not differ significantly. The distance in meters during 6MWT and the power of the exercise performed during bicycle ergometer test in MET have a significant relationship, which indicates the comparability of the data from these tests as a criterion of exercise tolerance. CONCLUSION. The use of 6MWT and bicycle ergometer test allows us to assess various aspects of cardiorespiratory function and physical fitness in patients undergoing a cardiac rehabilitation program. Further study of the possibility of using ECG-controlled 6MWT in the early stages of rehabilitation is necessary to create the most effective and safe physical training for patients who have suffered a myocardial infarction.

Accuracy of smartwatches for the remote assessment of exercise capacity

Exercise capacity is a strong independent predictor of cardiovascular and all-cause mortality. The utilization of well-established submaximal tests of exercise capacity such as the 6-min walk test (6MWT), 3-min step test (3MST) and 10-chair rise test (10CRT) in the community would improve patient care but requires remote monitoring technology. Consumer grade smartwatches provide such an opportunity, however, their accuracy in measuring physiological responses to these tests is unclear. The aim of this study was to determine the accuracy of consumer grade smartwatches in assessing exercise capacity to develop a framework for remote, unsupervised testing. 16 healthy adults (7 male (44%), age median 27 [interquartile range (IQR) 26,29] years) performed 6MWTs using two protocols: (1) standard—straight 30 m laps (6MWT-standard) and 2) continuous lap—circular 240 m laps around a park (6MWT-continuous lap), 3MSTs and 10CRTs. Each one of these four tests was performed three times across two clinic visits. Each participant was fitted with a Garmin Vivoactive4 and Fitbit Sense smartwatch to measure three parameters: distance, step counts and heart rate (HR) response. Reference measures were a meter-wheel, hand tally counter and ECG, respectively. Mean HR was measured at rest, peak exercise and recovery. Agreement was measured using Bland–Altman analysis for repeated measures and summarized as median absolute percentage errors (MAPE). Distance during 6MWT-continuous lap had better agreement than during 6MWT-standard for both Garmin (MAPE: 6.4% [3.0, 10.4%] versus 20.1% [13.9, 28.4%], p < 0.001) and Fitbit (8.0% [2.9, 10.1% versus 18.8% [15.2, 28.1%], p < 0.001). Garmin measured step count more accurately than Fitbit (MAPE: 1.8% [0.9, 2.9%] versus 8.0% [2.6, 12.3%], p < 0.001). Irrespective of test, both devices showed excellent accuracy in measuring HR at rest and recovery (≤ 3%), while accuracy decreased during peak exercise (Fitbit: ~ 12% and Garmin: ~ 7%). In young adults without mobility difficulties, exercise capacity can be measured remotely using standardized tests and consumer grade smartwatches.

Assessment Of Exercise Capacity With Submaximal Exerxise Using Arm Crank Ergometer: Comparison With Cycle Ergometer

Assessment Of Exercise Capacity With Submaximal Exerxise Using Arm Crank Ergometer: Comparison With Cycle Ergometer

The repeatability of a cycling exercise-heat stress test in a male population

IntroductionThere is considerable inter-individual variability in the physiological responses to environmental stressors and so to accurately assess and monitor changes in an individual's ability to cope with exercise-heat stress, a reliable protocol is required. The aim of this study was to examine the repeatability of a 90-min steady-state heat exercise bout with physiological and subjective variables, and performance during an incremental test to exhaustion post 90-min steady-state exercise. MethodSixteen mixed ability males (Age: 39 ± 15yrs; Height: 176.5 ± 4.8 cm; BM: 79.7 ± 10.3 kg; V˙O2peak: 46.2 ± 8.6 ml/kg/min; PPO: 309 ± 39W) who trained at least three times a week undertook two 90-min steady-state – followed by an incremental protocol to exhaustion – cycling heat stress tests (HSTs) in a hot-humid environment (35 °C, 60%RH). Heart rate (HR), rectal (T‾re) and skin temperature (T‾sk), rating of perceived exertion (RPE), thermal sensation (TS), and thermal comfort (TC) were measured throughout. Data was analysed using Intraclass Correlation Coefficients (ICC), technical error of measurement (TEM), Bland-Altman plots, t-tests, and Cohen's d to indicate magnitude of change. ResultsPhysiological variables indicated good repeatability evident through moderate to strong ICC ratings, low magnitudes of change (d), lower mean biases compared to their respective calculated TEMs, and statistical non-significance, except HR90, ₸sk90, and ₸sk. Hydration status showed good repeatability except for urine osmolality (osmu90) and resting urine colour (colu). Perceptual variables showed encouraging repeatability apart from resting TS and mean TS. Performance data showed good repeatability overall, however 11 participants progressed to the incremental test to exhaustion in the second visit compared to 7 in the first. ConclusionCurrent data demonstrated favourable physiological, perceptual, and performance repeatability during repeated cycling HSTs in hot-humid conditions. However, given more participants progressed to the incremental trial to exhaustion protocol in the second visit, at least one familiarisation trial may improve the reliability of exercise capacity assessment.

Establishing a novel model to assess exercise capacity in chronic heart failure based on stress echocardiography.

The aim of this study was to develop a simple, fast and efficient clinical diagnostic model, composed of exercise stress echocardiography (ESE) indicators, of the exercise capacity of patients with chronic heart failure (CHF) by comparing the effectiveness of different classifiers. Eighty patients with CHF (aged 60±11years; 78% male) were prospectively enrolled in this study. All patients underwent both cardiopulmonary exercise test (CPET) and ESE and were divided into two groups according to the VE/VCO2 slope: 30 patients with VE/VCO2 slope ventilation classification (VC)1 (i.e., VE/VCO2 slope<30) and 50 patients with VC2 (i.e., VE/VCO2 slope≥30). The analytical features of all patients in the four phases (rest, warm-up, peak and recovery phases) of ESE included the following parameters: left ventricular (LV) systolic function, LV systolic function reserve, LV diastolic function, LV diastolic function reserve and right ventricular function. Logistic regression (LR), extreme gradient boosting trees (XGBT), classification regression tree (CART) and random forest (RF) classifiers were implemented in a K-fold cross-validation model to distinguish VC1 from VC2 (LVEF in VC1 vs. VC2: 44±8% vs. 43±11%, P=0.617). Among the four models, the LR model had the largest area under the curve (AUC) (0.82; 95% confidence interval [CI]: 0.73 to 0.92). In the multiple-variable LR model, the differences between the peak-exercise-phase and resting-phase values of E (ΔE), s'peak and sex were strong independent predictors of a VE/VCO2 slope≥30 (P value: ΔE=0.002, s'peak=0.005, sex=0.020). E/e'peak, ΔLVEF, ΔLV global longitudinal strain and Δstroke volume were not predictors of VC in the multivariate LR model (P>0.05 for the above). Compared with the LR, XGBT, CART and RF models, the LR model performed best at predicting the VE/VCO2 slope category of CHF patients. A score chart was created to predict VE/VCO2 slopes≥30. ΔE, s'peak and sex are independent predictors of exercise capacity in CHF patients.

Association between growth differentiation factor-15 and adverse outcomes among patients with heart failure: A systematic literature review

Growth differentiation factor-15 (GDF-15) is an emerging biomarker in several conditions. This SLR, conducted following PRISMA guidelines, examined the association between GDF-15 concentration and range of adverse outcomes in patients with heart failure (HF). Publications were identified from Embase® and Medline® bibliographic databases between January 1, 2014, and August 23, 2022 (congress abstracts: January 1, 2020, to August 23, 2022). Sixty-three publications met the eligibility criteria (55 manuscripts and 8 abstracts; 45 observational studies and 18 post hoc analyses of randomized controlled trials [RCTs]). Of the 19 outcomes identified, the most frequently reported longitudinal outcomes were mortality (n = 32 studies; all-cause [n = 27] or cardiovascular-related [n = 6]), composite outcomes (n = 28; most commonly mortality ± hospitalization/rehospitalization [n = 19]), and hospitalization/re-hospitalization (n = 11). The most common cross-sectional outcome was renal function (n = 22). Among longitudinal studies assessing independent relationships with outcomes using multivariate analyses (MVA), a significant increase in risk associated with higher baseline GDF-15 concentration was found in 22/24 (92 %) studies assessing all-cause mortality, 4/5 (80 %) assessing cardiovascular-related mortality, 13/19 (68 %) assessing composite outcomes, and 4/8 (50 %) assessing hospitalization/rehospitalization. All (7/7; 100 %) of the cross-sectional studies assessing the relationship with renal function by MVA, and 3/4 (75 %) assessing exercise capacity, found poorer outcomes associated with higher baseline GDF-15 concentrations. This SLR suggests GDF-15 is an independent predictor of mortality and other adverse but nonfatal outcomes in patients with HF. A better understanding of the prognostic role of GDF-15 in HF could improve clinical risk prediction models and potentially help optimize treatment regimens.

Association between recovery from desaturation after stair climbing and postoperative complications in lung resection.

The stair-climbing test (SCT) is used as a surrogate for cardiopulmonary exercise testing, which measures maximal oxygen uptake, and considered a useful method for assessing exercise capacity in thoracic surgery. This study aims to investigate whether the recovery time of percutaneous oxygen saturation (SpO2) after stair climbing is a predictor of postoperative complications after lobectomy. We retrospectively identified 54 patients who performed SCT and underwent lobectomy between January 2015 and February 2023 at Shizuoka Cancer Center. The SpO2 recovery time was defined as the time required to recover from the minimum to resting value after stair climbing. The association between SpO2 recovery time and early postoperative pulmonary complications within 30days after surgery was analyzed. Eleven patients (20.4%) had postoperative pulmonary complications (≥ Clavien-Dindo Classification Grade 2). The cutoff value of SpO2 recovery time obtained from the receiver operating characteristic curve analysis was 90s [sensitivity, 81.8%; specificity, 72.1%; AUC, 0.77 (95% confidence interval, 0.64-0.90)]. The occurrence of postoperative pulmonary complications was 42.9% in the delayed recovery time (DRT; SpO2 recovery time ≥ 90s) group and 6.1% in the non-DRT (SpO2 recovery time < 90s) group (p = 0.002). DRT was a predictor of postoperative pulmonary complications (odds ratio, 11.60; 95% CI 2.19-61.80). DRT of SpO2 after stair climbing is a predictor of postoperative pulmonary complications following lobectomy in borderline patients who require exercise capacity assessment. SpO2 monitoring after stair climbing may be useful as one of the preoperative assessments in patients undergoing lobectomy.

The effect of pulmonary rehabilitation on cardiovascular risk, oxidative stress and systemic inflammation in patients with COPD

PurposeChronic obstructive pulmonary disease (COPD) is a leading cause of death, and cardiovascular (CV) comorbidities play a role. Evidence of the pulmonary rehabilitation (PR) effect in reducing the CV risk (CVR) in COPD patients is limited. In this study, we aimed to determine the impact of an 8-week PR program (PRP) on the CVR of the overall population and to compare the impact on the exacerbator versus non-exacerbator patients. Patients and methodsThis was a prospective study that included adults who had post-bronchodilator forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) (FEV1/FVC) ratio <70 % and FEV1 <80 % predicted, had quit smoking for at least 1 year and had a history of tobacco consumption greater than 10 packs/year, and were clinically stable in the last 8 weeks. Pre- and post-PRP assessments included respiratory function evaluation, laboratory tests, and exercise capacity assessment (6-min walking test [6MWT]). CVR was assessed using different risk prediction models. ResultsA total of 50 patients (28 exacerbators and 22 non-exacerbators) completed the PRP (median age: 64.5 years, men: 72 %; arterial hypertension: 70 %, dyslipidemia: 30 %, diabetes: 20 %; CV disease (CVD): 24 %. After the PRP, exacerbator patients showed a significant decrease in the CVR calculated by the COPDCoRi model (p < 0.001); patients with ≥30-m increase on the 6MWT showed statistically significant lower levels of glucose (p = 0.004), HbA1c (p = 0.004) and BODE index score (p = 0.026) compared to patients with <30-m increase. ConclusionsPR reduced certain modifiable CVR factors and CVD risk, especially in exacerbator patients.

An observational study to evaluate the within-day reliability and concurrent validity of 2-minute walk test (2MWT) and 10-metere walk test (10MWT) in health individuals wearing a mask

Background Exercise tests are widely used to prescribe exercises for patients with cardiorespiratory conditions and assess impact of treatments. The 2-minute walk test (2MWT) and 10-metre walk test (10MWT) are common assessments of functional exercise capacity. The COVID-19 pandemic resulted in people wearing masks (commonly surgical masks) to reduce infection. However, the validity and reliability of 2MWT and 10MWT wearing a mask is unknown and further research is required. Aim To assess the within-day reliability and concurrent validity of the 2MWT and 10MWT in healthy individuals wearing a surgical mask. Design and Setting Observational study, in a university setting Methods All participants completed three tests of 2MWT and 10MWT wearing a surgical mask (on one day) and one test without a mask (on a separate day) within one week. Oxygen saturation and heart rate were measured using pulse oximetry and the Borg scale assessed dyspnoea. Statistical analyses included: intraclass correlation coefficients (ICC) for within-day reliability of mask-wearing during three tests and Pearson’s coefficient for concurrent validity correlated tests with a surgical mask and without a mask (the gold standard). Results 15 people, mean (standard deviation) age 26 (2) years were included. The 2MWT and 10MWT (with mask) had excellent within-day reliability (ICC =0.823, 0.920 respectively). Both the 2MWT and 10MWT with and without a mask were highly correlated (r = 0.815, 0.943 respectively, p&lt;0.01). Conclusions The results showed excellent within-day reliability and concurrent validity of 2MWT and 10MWT with a surgical mask in healthy individuals. Further research in clinical populations is needed.

WS08.04 Assessment of functional exercise capacity using telehealth: reliability, validity, and usability in children with cystic fibrosis

WS08.04 Assessment of functional exercise capacity using telehealth: reliability, validity, and usability in children with cystic fibrosis

An Exercise Immune Fitness Test to Unravel Disease Mechanisms-A Proof-of-Concept Heart Failure Study.

Background: Cardiorespiratory fitness positively correlates with longevity and immune health. Regular exercise may provide health benefits by reducing systemic inflammation. In chronic disease conditions, such as chronic heart failure and chronic fatigue syndrome, mechanistic links have been postulated between inflammation, muscle weakness, frailty, catabolic/anabolic imbalance, and aberrant chronic activation of immunity with monocyte upregulation. We hypothesize that (1) temporal changes in transcriptome profiles of peripheral blood mononuclear cells during strenuous acute bouts of exercise using cardiopulmonary exercise testing are present in adult subjects, (2) these temporal dynamic changes are different between healthy persons and heart failure patients and correlate with clinical exercise-parameters and (3) they portend prognostic information. Methods: In total, 16 Heart Failure (HF) patients and 4 healthy volunteers (HV) were included in our proof-of-concept study. All participants underwent upright bicycle cardiopulmonary exercise testing. Blood samples were collected at three time points (TP) (TP1: 30 min before, TP2: peak exercise, TP3: 1 h after peak exercise). We divided 20 participants into 3 clinically relevant groups of cardiorespiratory fitness, defined by peak VO2: HV (n = 4, VO2 ≥ 22 mL/kg/min), mild HF (HF1) (n = 7, 14 < VO2 < 22 mL/kg/min), and severe HF (HF2) (n = 9, VO2 ≤ 14 mL/kg/min). Results: Based on the statistical analysis with 20-100% restriction, FDR correction (p-value 0.05) and 2.0-fold change across the three time points (TP1, TP2, TP3) criteria, we obtained 11 differentially expressed genes (DEG). Out of these 11 genes, the median Gene Expression Profile value decreased from TP1 to TP2 in 10 genes. The only gene that did not follow this pattern was CCDC181. By performing 1-way ANOVA, we identified 8/11 genes in each of the two groups (HV versus HF) while 5 of the genes (TTC34, TMEM119, C19orf33, ID1, TKTL2) overlapped between the two groups. We found 265 genes which are differentially expressed between those who survived and those who died. Conclusions: From our proof-of-concept heart failure study, we conclude that gene expression correlates with VO2 peak in both healthy individuals and HF patients, potentially by regulating various physiological processes involved in oxygen uptake and utilization during exercise. Multi-omics profiling may help identify novel biomarkers for assessing exercise capacity and prognosis in HF patients, as well as potential targets for therapeutic intervention to improve VO2 peak and quality of life. We anticipate that our results will provide a novel metric for classifying immune health.

Exercise capacity after COVID-related multisystem inflammatory syndrome in children-A cross-sectional study

BackgroundAfter recovery from COVID-19 associated multisystem inflammatory syndrome in children (MISC), exercise restrictions were advised for 6 months. Studies done to assess exercise capacity at 3–6 months post recovery from MISC, prior to withdrawal of exercise restrictions, yielded varying information. Whether their exercise capacity was on par with their peers at/beyond 1-year post-recovery needed to be assessed. ObjectivesPrimary: To compare the exercise capacity between children with a history of MISC and unaffected childrenSecondary: To compare the exercise capacity between a) children with a history of MISC and children with a history of COVID but not MISC b) children with a history of COVID but not MISC and unaffected children. MethodsChildren (aged ≥8 years) who had recovered from MISC >1-year ago (n = 21) were compared with unaffected children (n = 42) and children who had COVID but not MISC (n = 21) respectively using cardiopulmonary exercise testing (CPET). Comparisons were made between 1. Post-MISC vs unaffected 2. Post-MISC vs post-COVID 3. Post-COVID vs unaffected. ResultsCompared with unaffected children, post-MISC and post-COVID groups had similar peak oxygen uptake (VO2 max) but significantly lesser exercise duration. Children who were very sick during their hospitalization for MISC had an exercise capacity comparable to others in the post-MISC group. Overweight/obese children in post-MISC group had a significantly lesser exercise capacity. But, the numbers of overweight/obese children and very sick children were not adequate to run a separate sub-group analysis. ConclusionsAt/beyond 1 year post-recovery from MISC, exercise capacity was comparable to healthy children and children who had COVID but not MISC, but exercise duration was significantly less. Overweight/obese children need to be followed up longer with emphasis on regular exercises. Children who were very sick during MISC hospitalization had recovered their exercise capacity.