Exercise for chronic kidney disease: effects on vascular and cardiopulmonary function.

Patients with chronic kidney disease (CKD) have an exacerbated prevalence of cardiovascular disease (CVD). Vascular dysfunction, characterized by impaired endothelial function and arterial stiffness, and markedly low cardiorespiratory fitness levels are hallmark manifestations of the disease that contribute to the CVD burden. Despite advancements in blood pressure and lipid lowering pharmacological therapies, CVD remains markedly prevalent across the spectrum of CKD. This highlights a stagnation in effective clinical strategies to improve cardiovascular health and reinforces the critical need for adjuvant lifestyle strategies such as physical activity and exercise training to be incorporated into routine clinical care. This narrative review provides an overview of the known effects of exercise on vascular and cardiopulmonary function across the spectrum of CKD. The physiological mechanisms of vascular dysfunction that serve as exercise-specific therapeutic targets are highlighted and future perspectives are discussed.

Effect of different intensity exercises on cardiopulmonary function and quality of life of patients with chronic heart failure : A systematic review and meta-analysis.

BACKGROUND: Exercise-based cardiac rehabilitation has positive benefits for patients with chronic heart failure (CHF), but the choice of exercise intensity has been controversial. The aim of this systematic review and meta-analysis was to investigate the effects of different exercise intensities on cardiopulmonary function and quality of life (QoL) of patients with CHF. METHODS: Randomized controlled trials (RCTs) of different exercise intensities applied to patients with CHF were searched in PubMed, Web of Science, the Cochrane Library, and Embase databases from inception to December 2021. Study selection and data extraction were performed simultaneously by two independent reviewers, using the Physiotherapy Evidence Database Scale (PEDro) for quality assessment of the included literature. The weighted mean differences (WMD) or standardized mean difference (SMD) were calculated by employing a fixed or random effects model. Other statistical analyses included subgroup analysis and sensitivity analysis. Quality of evidence was evaluated by the Grade of Recommendation, Assessment, Development, and Evaluation (GRADE) method. RESULTS: Eight RCTs were included. Analyses reported no significant improvement in left ventricular ejection fractions (LVEF; WMD = 0.47, 95% CI [-4.10, 5.03], p = 0.841), peak oxygen uptake (peak VO2) (SMD = 0.38, 95% CI [-0.03, 0.80], p = 0.069) and 6­min walking distance (6MWD) (WMD = 14.10, 95% CI [-9.51, 37.72], p = 0.242). Exercise interventions of varying intensity produced small-to-moderate beneficial effects on QoL (WMD = -4.99, 95% CI [-8.29, -1.68], p = 0.003), which appeared to be attenuated at long-term follow-up (WMD = 2.12, 95% CI [-2.91, 7.16], p = 0.409). CONCLUSION: High-intensity exercise does not have a significant advantage over moderate-intensity exercise in improving cardiopulmonary function and aerobic capacity in patients with CHF. Beneficial changes in QoL from high-intensity exercise also appeared to decrease during long-term follow-up, indicating a cumulative effect of the efficacy of high-intensity exercise.

Pectus excavatum: the effect of tricuspid valve compression on cardiac function.

BACKGROUND: Pectus excavatum (PE) is a common congenital chest wall deformity with various associated health concerns, including psychosocial impacts, academic challenges, and potential cardiopulmonary effects. OBJECTIVE: This study aimed to investigate the cardiac consequences of right atrioventricular groove compression in PE using cardiac magnetic resonance imaging. MATERIALS AND METHODS: A retrospective analysis was conducted on 661 patients with PE referred for evaluation. Patients were categorized into three groups based on the degree of right atrioventricular groove compression (no compression (NC), partial compression (PC), and complete compression(CC)). Chest wall indices were measured: pectus index (PI), depression index (DI), correction index (CI), and sternal torsion. RESULTS: The study revealed significant differences in chest wall indices between the groups: PE, NC=4.15 ± 0.94, PC=4.93 ± 1.24, and CC=7.2 ± 4.01 (P<0.0001). Left ventricle ejection fraction (LVEF) showed no significant differences: LVEF, NC=58.72% ± 3.94, PC=58.49% ± 4.02, and CC=57.95% ± 3.92 (P=0.0984). Right ventricular ejection fraction (RVEF) demonstrated significant differences: RVEF, NC=55.2% ± 5.3, PC=53.8% ± 4.4, and CC=53.1% ± 4.8 (P≥0.0001). Notably, the tricuspid valve (TV) measurement on the four-chamber view decreased in patients with greater compression: NC=29.52 ± 4.6; PC=28.26 ± 4.8; and CC=24.74 ± 5.73 (P<0.0001). CONCLUSION: This study provides valuable insights into the cardiac consequences of right atrioventricular groove compression in PE and lends further evidence of mild cardiac changes due to PE.

The application value of lung ultrasound scoring in assessing disease severity: Evaluation of small-scale outbreaks of COVID-19.

PURPOSE: This study explored the use of transthoracic lung ultrasound for evaluating COVID-19 patients, compared it with computed tomography (CT), and examined its effectiveness using 8 and 12 lung regions. METHODS: A total of 100 patients with COVID-19 and 40 healthy volunteers were assessed using 12 regions (bilateral upper/lower regions of the anterior/lateral/posterior chest) and simplified 8 zones (bilateral upper/lower regions of the anterior/lateral chest) transthoracic lung ultrasound. The relationships between ultrasound, CT, and clinical indicators were analyzed to evaluate the diagnostic value of ultrasound scores in COVID-19. RESULTS: Increased disease severity correlated with increased 8- and 12-zone ultrasound and CT scores (all p < 0.05). The modified 8-zone method strongly correlated with the 12-zone method (Pearson's r = 0.908, p < 0.05). The 8- and 12-zone methods correlated with CT scoring (correlation = 0.568 and 0.635, respectively; p < 0.05). The intragroup correlation coefficients of the 8-zone, 12-zone, and CT scoring methods were highly consistent (intragroup correlation coefficient = 0.718, p < 0.01). The 8-zone ultrasound score correlated negatively with oxygen saturation (rs = 0.306, p < 0.05) and Ca (rs = 0.224, p < 0.05) and positively with IL-6 (rs = 0.0.335, p < 0.05), erythrocyte sedimentation rate (rs = 0.327, p < 0.05), alanine aminotransferase (rs = 0.230, p < 0.05), and aspartate aminotransferase (rs = 0.251, p < 0.05). The 12-zone scoring method correlated negatively with oxygen saturation (rs = 0.338, p < 0.05) and Ca (rs = 0.245, p < 0.05) and positively with IL-6 (rs = 0.354, p < 0.05) and erythrocyte sedimentation rate (rs = 0.495, p < 0.05). CONCLUSION: Lung ultrasound scores represent the clinical severity and have high clinical value for diagnosing COVID-19 pneumonia. The 8-zone scoring method can improve examination efficiency and reduce secondary injuries caused by patient movement.

Effectiveness and Influencing Factors of Home-Center-Based Cardiac Rehabilitation as a Transitional Strategy for Acute Myocardial Infarction Patients.

Currently, providing patients, particularly those with acute myocardial infarction (AMI), with comprehensive cardiac rehabilitation (CR) has been challenging because of the inadequate availability of medical resources in developing countries. To ensure balance between disease instability and early rehabilitation, strategies for facilitating professional and comprehensive CR opportunities for patients with AMI must be explored.A prospective cohort study was carried out on 1,533 patients with AMI who were admitted to a tertiary hospital between July 2018 and October 2019. Following the principle of voluntarism, 286 patients with AMI participated in home-center-based CR (HCB group), whereas 1,247 patients received usual care (UC group). The primary endpoint of this study was the occurrence of cardiovascular events at 30 months after AMI. Moreover, the study analyzed factors that influence participation rate and effectiveness of the CR model.After analysis, a significant difference in the occurrence of cardiovascular endpoints between the HCB group and the UC group was observed (harzard ratio, 0.68 [95%CI, 0.51-0.91], P = 0.008), with participation in home-center-based CR being an independent influencing factor. Multivariate regression analysis revealed age, gender, smoking history, triglyceride levels, and ejection fraction as independent factors that influence participation rate. Female gender, peak oxygen uptake per kilogram body weight, and ventilation/carbon dioxide production slope were identified as factors that affect the effectiveness of the CR model.In the context of developing countries, this study demonstrates that the home-center-based CR model is efficient and analyzes factors that influence participation rate and effectiveness of the model. These findings provide practical insights for further development of CR programs.

Impact of diabetes on cardiopulmonary function: the added value of a combined cardiopulmonary and echocardiography stress test.

Type 2 diabetes mellitus (T2DM) represents a major health issue worldwide, as patients with T2DM show an excess risk of death for cardiovascular causes, twice as high as the general population. Among the many complications of T2DM, heart failure (HF) deserves special consideration as one of the leading causes of morbidity and reduced life expectancy. T2DM has been associated with different phenotypes of HF, including HF with reduced and preserved ejection fraction. Cardiopulmonary exercise testing (CPET) can evaluate the metabolic and ventilatory alterations related to myocardial dysfunction and/or peripheral impairment, representing a unique tool for the clinician to study the whole HF spectrum. While CPET allows for a thorough evaluation of functional capacity, it cannot directly differentiate central and peripheral determinants of effort intolerance. Combining CPET with imaging techniques could provide even higher accuracy and further insights into the progression of the disease since signs of left ventricular systolic and diastolic dysfunction can be detected during exercise, even in asymptomatic diabetic individuals. This review aims to dissect the alterations in cardiopulmonary function characterising patients with T2DM and HF to improve patient risk stratification.

Effect of large volume red blood cell apheresis on cardiovascular functions in healthy donors.

BACKGROUND: Requirements of blood transfusions rise rapidly in China. Improving the efficiency of blood donation could help maintaining sufficient blood supplement. We conducted a pilot research to investigate the reliability and safety of collecting more units of red blood cell by apheresis. METHODS: Thirty-two healthy male volunteers were randomized into two groups: red blood cell apheresis (RA) (n = 16) and whole blood (WB) donation (n = 16). RA group donated individualized RBC volumes by apheresis according to the volunteers' basal total blood volumes and haematocrit levels, WB group donated 400 mL whole blood. All volunteers were scheduled seven visit times in 8 weeks' study period. The cardiovascular functions were assessed by laboratory examinations, echocardiography and cardiopulmonary functional tests. All results were compared between groups at the same visit time and compared between visit 1(before donation) and other visit times within the same group. RESULTS: The average donated RBC volume in RA group and in WB group was 627.25 ± 109.74 mL and 175.28 ± 8.85 mL, respectively(p < 0.05); the RBC, haemoglobin and haematocrit levels changed significantly between times and between groups (p < 0.05). Cardiac biomarker levels such as NT-proBNP, hs-TnT and CK-MB did not change significantly between times or between groups (p > 0.05). The echocardiographic and cardiopulmonary results did not change significantly between times or between groups during the whole study period(p > 0.05). CONCLUSIONS: We provided an efficient and secure method for RBC apheresis. By harvesting more RBC volumes at one single-time, the cardiovascular functions did not change significantly compared with traditional whole blood donation.

Exercise as the Key to Improve Cardiopulmonary Function in Patients with Valvular Heart Disease: A Systematic Review and Meta-Analysis.

Background: Valvular heart disease (VHD) is a type of cardiovascular disease with abnormal heart valve structure and/or function and a rapidly growing cause of global cardiovascular morbidity and mortality. Physical inactivity is a problem for patients with VHD, especially after surgery. However, there is no data on the effects of exercise on VHD from large multicentre randomised controlled trials (RCTs). Therefore, we conducted a systematic review and meta-analysis to provide a comprehensive analysis of small RCTs to evaluate the effects of exercise on cardiopulmonary function in patients with VHD and provide an evidence-based medicine basis for developing and guiding the clinical application of exercise in patients with VHD. Methods: We conducted a systematic review and meta-analysis of RCTs. We systematically searched electronic databases (PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure [CNKI], China Science and Technology Journal Database [VIP], WanFang Database, and SinoMed [CBM]) for all studies on exercise and VHD from their inception to January 2023. The quality of included studies was assessed using the Cochrane risk-of-bias tool. The primary outcomes were the six-minute walk test distance (6MWD), left ventricular ejection fraction (LVEF), and short-form 36-item health survey (SF-36). Results: This systematic review included 22 RCTs with 1520 subjects (869 men and 651 women). The meta-analysis results showed that exercise significantly improved exercise capacity measured by the 6MWD (mean difference [MD] = 25.54, 95% confidence interval [CI] = 19.98-31.11, I 2 = 0%, p < 0.00001), LVEF (MD = 6.20, 95% CI = 4.76-7.65, I 2 = 66%, p < 0.00001), and quality of life measured by the SF-36 (physical function: MD = 3.42, 95% CI = 2.12-4.72, I 2 = 12%, p < 0.00001; mental health: MD = 3.86, 95% CI = 0.52-7.20, I 2 = 68%, p = 0.020; social function: MD = 2.30, 95% CI = 0.64-3.97, I 2 = 45%, p = 0.007; bodily pain: MD = 2.60, 95% CI = 0.83-4.37, I 2 = 22%, p = 0.004) in patients with VHD compared to healthy controls. Conclusions: This study suggests that exercise can significantly improve cardiopulmonary function, enhance physical and social function, reduce bodily pain, and potentially improve mental health in patients with VHD, providing an evidence-based basis for better recovery in patients with VHD.

A randomized controlled crossover trial of acute intermittent and continuous hypoxia exposure in mild-moderate obstructive sleep apnea: A feasibility study.

In a prospective, randomized, controlled crossover study, we explored the effects of acute intermittent hypoxia and acute continuous hypoxia on patients with mild-moderate obstructive sleep apnea. Over three single-night sessions, subjects were alternately exposed to normoxia, acute continuous hypoxia and acute intermittent hypoxia before sleep. The apnea-hypopnea index and oxygen desaturation index were used to diagnose obstructive sleep apnea and evaluate efficacy. A responder was defined as a participant with a ≥ 50% reduction in apnea-hypopnea index between normoxia and hypoxia exposure. Sixteen participants with mild-moderate obstructive sleep apnea completed the study. Compared with normoxia, the mean apnea-hypopnea index decreased by 8.9 events per hr (95% confidence interval, 4.2-13.6, p = 0.001) with acute intermittent hypoxia and by 4.1 events per hr (95% confidence interval, 0.5-8.8, p = 0.082) with acute continuous hypoxia, equating to a mean decrease in apnea-hypopnea index of 4.8 events per hr (95% confidence interval, 0.1-9.5, p = 0.046) with acute intermittent hypoxia compared with acute continuous hypoxia. Compared with normoxia, the mean oxygen desaturation index decreased by 9.8 events per hr (95% confidence interval, 4.4-15.1, p = 0.001) with acute intermittent hypoxia but did not significantly decrease with acute continuous hypoxia; the mean oxygen desaturation index decreased by 7.2 events per hr (95% confidence interval, 1.8-12.6, p = 0.010) with acute intermittent hypoxia compared with acute continuous hypoxia. Of the 16 participants, 11 responded to acute intermittent hypoxia and four responded to acute continuous hypoxia (p = 0.032), of whom eight of 11 cases and all four cases had oxygen desaturation indexes <5 events per hr, respectively (p = 0.273). All participants tolerated acute intermittent hypoxia and there were no obvious adverse events during acute intermittent hypoxia exposure. In conclusion, acute intermittent hypoxia exposure improved apnea-hypopnea index and oxygen desaturation index in patients with mild-moderate obstructive sleep apnea, suggesting that further prospective validation of intermittent hypoxia exposure in patients with obstructive sleep apnea is needed to establish its clinical feasibility as a therapeutic modality.

Factors associated with failure of cardiopulmonary function recovery after lung cancer surgery.

BACKGROUND AND OBJECTIVE: This study aimed to evaluate the longitudinal changes in cardiopulmonary function (CPF) and identify predictors of cardiopulmonary recovery failure after lung cancer surgery. METHODS: Data was obtained from a prospective CATCH-LUNG cohort study, where patients were divided into two groups based on 6-min walk distance (6MWD) at baseline and 6 months after surgery. CPF recovery failure was defined as a participant whose 6MWD dropped over 50 m from baseline to 6 months after surgery. Patients with a baseline 6MWD less than 400 m were excluded. The analysis was investigated using mixed effects models, and the relative estimates for the predictors were expressed relative risk (RR) and 95% CI using a Poisson regression. RESULTS: Among 419 patients, 24.1% and 17.7% showed failure of CPF recovery at 6 months and 1 year after surgery, respectively. In the multivariable analysis, baseline step count [RR per 1000 steps lower = 1.05 (95% CI, 1.01-1.09)], baseline dyspnoea [RR per 10 points higher = 1.15(1.07-1.23)], decreased FEV1 % predicted from baseline to 2 weeks after surgery [RR per 10% lower = 1.30(1.10-1.53)] and decreased moderate-to-vigorous physical activity (MVPA) from baseline to 2 weeks [RR = 1.95(1.22, 3.11)] or persistent low MVPA at baseline and 2 weeks after surgery [RR = 1.63(1.04, 2.54)] were significant factors for loss of CPF. CONCLUSION: The inability to recover CPF at 6 months after surgery was linked to reduction of lung function and MVPA from baseline to 2 weeks as well as baseline physical activity (PA) and dyspnoea. These results imply that engagement of perioperative PA is necessary to facilitate recovery of CPF after lung cancer surgery.

Changes in Exercise Tolerance over Time in Patients with Transthyretin Amyloidosis Cardiomyopathy Treated with Tafamidis.

Tafamidis improves the prognosis of patients with transthyretin amyloidosis cardiomyopathy (ATTR-CM). Additionally, it delays the decline in exercise tolerance, as observed in the six-minute walking test. However, the changes in cardiopulmonary function over time based on cardiopulmonary exercise tests are unclear. Thus, this preliminary study investigated the changes in exercise tolerance after one year of tafamidis treatment using cardiopulmonary exercise testing. Eight patients with ATTR-CM (average age: 77 years; male: n = 7) underwent cardiopulmonary exercise testing at baseline and after one year of tafamidis treatment. All eight patients completed a one-year follow-up. At baseline, the anaerobic threshold oxygen uptake (AT VO2: 10.9 ± 1.5) and peak VO2 (14.3 ± 3.0 mL/kg/minute) indicated relatively favorable exercise capacity; however, the minute ventilation/carbon dioxide production (VE/VCO2 slope), which indicates effective ventilation, showed poor performance (33.7 ± 12.8). One year after tafamidis treatment, frailty, as assessed by the Clinical Frailty Scale, had progressed in seven of eight patients (88%) (P < 0.01), and AT VO2 and peak VO2 were significantly reduced (19.2% and 22.3%, respectively; P < 0.05). The VE/VCO2 slope and peak O2 pulse decreased nonsignificantly by approximately 20% (P = 0.47, and P = 0.16, respectively). Further, the structure of the ventricles and atrium and the left ventricle ejection fraction on echocardiography did not change. Thus, exercise tolerance in patients with ATTR-CM was reduced after one year despite tafamidis administration. Not only ATTR-CM progression, but also frailty progression may influence this decrease in exercise tolerance. A comprehensive approach, including tafamidis administration and cardiac rehabilitation, is required for further improvement in the exercise capacity of patients with ATTR-CM.

Breast cancer survivors with preserved or rescued cardiorespiratory fitness have similar cardiac, pulmonary and muscle function compared to controls.

Breast cancer survivors (BCS) have a high prevalence of cardiovascular disease and low cardiorespiratory fitness (CRF). CRF is an important predictor of survival in BCS. However, the physiological factors that contribute to low CRF in BCS have not been completely elucidated. To assess differences in physiological factors (cardiac, pulmonary, muscle function) related to CRF between BCS and controls. Twenty-three BCS and 23 age-body mass index (BMI) matched controls underwent a peak cycling exercise test to determine CRF, with physiological factors measured at resting and at peak exercise. Cardiac hemodynamics (stroke volume [SV], SVindex, heart rate [HR], cardiac output [Formula: see text], and [Formula: see text]index) were evaluated using ultrasonography. Pulmonary function was evaluated using the oxygen uptake efficiency slope (OUES), ventilation to carbon dioxide production slope [Formula: see text] and breathing reserve at peak exercise (BR). Muscle oxygenation variables (oxygenated [HbO2] deoxygenated [HHb] and total hemoglobin [Hb], and tissue oxygenation index [TSI]) were measured with near-infrared spectroscopy (NIRS). Both groups had similar CRF and similarly increased all hemodynamic variables (HR, SV, SVindex, [Formula: see text] and [Formula: see text]index) at peak exercise compared to resting (p < 0.001). BCS had higher overall HR and lower SVindex (group effect, p < 0.05). BCS had similar OUES, [Formula: see text] and BR compared to the controls. Both groups decreased TSI, and increased Hb and HHb similarly at peak exercise compared to resting (p < 0.001). Our data suggest BCS do not exhibit differences in cardiac, pulmonary, or muscle function at peak exercise compared to controls, when both groups have similar CRF and physical activity.

A multi-disciplinary rehabilitation approach for people surviving severe COVID-19-a case series and literature review.

BACKGROUND/PURPOSE: COronaVIrus Disease 2019 (COVID-19) has caused tremendous casualties and morbidities worldwide. Multisystem manifestations, including muscle weakness, dyspnea, cognitive decline, dysphagia, and dysarthria are frequently reported among critically ill patients. The resultant activity limitations and participation restrictions call for an organized and multidisciplinary approach to rehabilitation. Taiwan had a rapid surge in community infection cases from May to July 2021, and our team established a team-based approach in response to the rehabilitation needs for the in-patients, especially the critically-ill group. METHODS: We built a core treatment team and established a referral pathway for critically ill patients with COVID-19 based on a multidisciplinary approach. The care process and outcomes of a case series of patients who received in-patient rehabilitation after medical stabilization were presented. RESULTS: Our clinical care module was established according to interim World Health Organization guidance and current research and demonstrated a high degree of feasibility. Five patients with multiple impairments received in-patient rehabilitation and experienced significant functional improvement. We documented improvements in motor function, swallowing function, and activities of daily living after the rehabilitation. CONCLUSION: Our clinical experience suggests considerable benefits can be obtained from a well-organized and multidisciplinary rehabilitation approach for severe COVID-19 patients.

Muscle oxygen extraction and lung function are related to exercise tolerance after allogeneic hematopoietic stem cell transplantation.

PURPOSE: This study aimed to investigate the relationship between exercise intolerance, muscle oxidative metabolism, and cardiopulmonary function following allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a sterile isolation room setting. METHODS: This was a prospective observational cohort study conducted in a single center. Fourteen patients with hematopoietic malignancies who had undergone allo-HSCT were included in this study from June 2015 to April 2020. Patients received donor HSCT after high dose-chemotherapy and total-body irradiation. Physical activity was limited during treatments. Outcome measures included body anthropometric measurements, exercise tolerance tests using the ramp protocol, pulmonary function tests, and near-infrared spectroscopy (NIRS) measurements. Data of pre- and posttransplant measurements were compared using the paired t test or nonparametric Wilcoxon U test. Associations were assessed using the Pearson or nonparametric Spearman correlations. RESULTS: NIRS showed reduced muscle consumption and extraction of oxygen in the posttransplant period compared to the pretransplant period (ΔStO2 min pre: -18.6% vs. post: -13.0%, P = 0.04; ΔHHb max pre: 4.21µmol/l vs. post: 3.31µmol/l: P = 0.048). Exercise tolerance had reduced following allo-HSCT (Peak workload pre: 70.3 W vs. post: 58.0 W: P = 0.014). Furthermore, exercise intolerance was associated with pulmonary function, muscle oxygen consumption, and muscle oxygen extraction (all P <0.05). CONCLUSION: This analysis revealed that exercise intolerance following allo-HSCT was associated with pulmonary dysfunction and muscle oxidative dysfunction. These findings could help identify the physical function associated with impaired tissue oxygen transport leading to exercise intolerance following allo-HSCT.

Chemical constituents and sources of indoor PM2.5 and cardiopulmonary function in patients with chronic obstructive pulmonary disease: Estimation of individual and joint effects.

BACKGROUND: The cardiopulmonary effects of chemical constituents and sources of indoor fine particulate matter (PM2.5) remain unclear. OBJECTIVES: To examine the individual and joint effects of constituents of indoor PM2.5 on cardiopulmonary function of patients with chronic obstructive pulmonary disease (COPD) and the role of identified sources. METHODS: This panel study recruited 43 stable COPD patients from November 2015 to May 2016 in Beijing, China. Daily indoor and outdoor PM2.5 were collected for five consecutive days simultaneously. Twenty-four elements were measured and principal component analysis was used for source appointment. Pulmonary function and blood pressure (BP) were also measured at daily visit. The linear mixed-effect models were used to estimate the effect of each constituent and source. Bayesian kernel machine regression (BKMR) models were used to estimate the overall effect of all measured constituents. RESULTS: The combustion, indoor soil/dust and road dust sources were identified as the main sources of indoor PM2.5 and combustion sources contributed over 40% during the heating season. Most constituents were significantly associated with elevated BP of COPD patients and the joint effects of mixed exposures were also significant especially during the heating season. Most associations of chemical constituents with pulmonary function were negative but not statistically significant during the heating season, as was the joint effect. Few associations were observed during the non-heating season. Further, we observed combustion sources throughout the study period and road dust sources during the heating season were significantly associated with increased BP but not decreased pulmonary function. CONCLUSION: The combustion and road dust sources and their related constituents of indoor PM2.5 could cause adverse effects on cardiovascular function of COPD patients especially during the heating season, but the effect on pulmonary function still needs to be further studied.

Cardiopulmonary response to high-altitude mountaineering in lung transplant recipients-The Jebel Toubkal experience.

OBJECTIVES: Only a small proportion of lung transplant recipients achieve a physical status comparable to healthy individuals in the long term. It is reasonable to hypothesize that the necessary cardiopulmonary adaptation required for strenuous physical exercise may be impaired. Exposure to high altitude provides an optimal platform to study the physiological cardiopulmonary adaptation in lung transplant recipients under aerobic conditions. To gain a deeper understanding, 14 healthy lung transplant recipients and healthcare professionals climbed the highest peak in North Africa (Mount Jebel Toubkal; 4167 m) in September 2019. METHODS: Monitoring included daily assessment of vital signs, repeated transthoracic echocardiography, pulmonary function tests, and capillary blood sampling throughout the expedition. RESULTS: Eleven out of fourteen lung transplant recipients reached the summit. All recipients showed a stable lung function and vital parameters and physiological adaptation of blood gases. Similar results were found in healthy controls. Lung transplant recipients showed worse results in the 6-minute walk test at low and high altitude compared to controls (day 1: 662 m vs. 725 m, p < 0.001, day 5: 656 m vs. 700 m, p = 0.033) and a lack of contractile adaptation of right ventricular function with increasing altitude as measured by tricuspid plane systolic excursion on echocardiography (day 2: 22 mm vs. 24 mm, p = 0.202, day 5: 23 mm vs. 26 mm, p = 0.035). CONCLUSIONS: Strenuous exercise in healthy lung transplant recipients is safe. However, the poorer cardiopulmonary performance in the 6-minute walk test and the lack of right ventricular cardiac adaptation may indicate underlying autonomic dysregulation.

Factors related to instrumental activities of daily living in persons with chronic thromboembolic pulmonary hypertension.

Instrumental activities of daily living (IADL) are significantly related to quality of life and mortality among individuals with heart disease. However, few reports have examined IADL in persons with chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to clarify factors related to IADL in persons with CTEPH. This retrospective, observational study enrolled 163 persons with CTEPH (mean ± standard deviation age = 65 ± 13 years; 68% female) admitted to the Department of Cardiology at Keio University Hospital between January 2015 and July 2019. The Frenchay Activities Index (FAI) was used to assess IADL. Age, sex, body mass index, World Health Organization functional class (WHO-FC), cardiac function (mean pulmonary arterial pressure, mean right atrial pressure, pulmonary capillary wedge pressure, and cardiac index), pulmonary function (percentage vital capacity, percentage forced expiratory volume in 1 s, diffusion capacity of carbon monoxide (DLCO)/alveolar volume (VA)), physical function (knee extension strength and walking speed), and 6-min walking distance (6MWD) were assessed. Multiple regression analysis was performed to identify factors significantly associated with FAI. Mean FAI was 25 ± 8. Univariate analysis showed that sex, WHO-FC, DLCO/VA, walking speed, and 6MWD were correlated with FAI. Multiple regression analysis showed that 6MWD (sß = 0.338, 95% CI 0.014-0.034, p < .001), sex (sß = 0.268, 95% CI 2.238-7.165, p < .001), and DLCO/VA (sß = 0.257, 95% CI 1.011-3.528, p < .001) were significantly correlated with FAI (R2 = 0.261). IADL were associated with exercise tolerance, sex, and DLCO/VA in persons with CTEPH. In the future, more details of IADL are expected to be clarified by analyzing individual components of IADL and investigating social background characteristics, including living environment.

Dyspnea, effort and muscle pain during exercise in lung transplant recipients: an analysis of their association with cardiopulmonary function parameters using machine learning.

BACKGROUND: Despite improvement in lung function, most lung transplant (LTx) recipients show an unexpectedly reduced exercise capacity that could be explained by persisting peripheral muscle dysfunction of multifactorial origin. We analyzed the course of symptoms, including dyspnea, muscle effort and muscle pain and its relation with cardiac and pulmonary function parameters during an incremental exercise testing. METHODS: Twenty-four bilateral LTx recipients were evaluated in an observational cross-sectional study. Recruited patients underwent incremental cardio-pulmonary exercise testing (CPET). Arterial blood gases at rest and peak exercise were measured. Dyspnea, muscle effort and muscle pain were scored according to the Borg modified scale. Potential associations between the severity of symptoms and exercise testing parameters were analyzed using a Forest-Tree Machine Learning approach, which accomplishes for a ratio between number of observations and number of screened variables less than unit. RESULTS: Dyspnea score was significantly associated with maximum power output (WR, watts), and minute ventilation (VE, L/min) at peak exercise. In a controlled subgroup analysis, dyspnea score was a limiting symptom only in LTx recipients who reached the higher levels of WR (≥ 101 watts) and VE (≥ 53 L/min). Muscle effort score was significantly associated with breathing reserve as percent of maximal voluntary ventilation (BR%MVV). The lower the BR%MVV at peak exercise (< 32) the higher the muscle effort perception. Muscle pain score was significantly associated with VO2 peak, arterial [HCO3-] at rest, and VE/VCO2 slope. In a subgroup analysis, muscle pain was the limiting symptom in LTx recipients with a lower VO2 peak (< 15 mL/Kg/min) and a higher VE/VCO2 slope (≥ 32). CONCLUSIONS: The majority of our LTx recipients reported peripheral limitation as the prevalent reason for exercise termination. Muscle pain at peak exercise was strictly associated with basal and exercise-induced metabolic altered pathways. The onset of dyspnea (breathing effort) was associated with the intensity of ventilatory response to meet metabolic demands for increasing WR. Our study suggests that only an accurate assessment of symptoms combined with cardio-pulmonary parameters allows a correct interpretation of exercise limitation and a tailored exercise prescription. The role and mechanisms of muscle pain during exercise in LTx recipients requires further investigations.

Exercise Field Testing in Children: A New Approach for Age-Appropriate Evaluation of Cardiopulmonary Function.

Based on the wide range of problems to effectively perform cardiopulmonary testing in young children, this study strives to develop a new cardiopulmonary exercise test for children using a mobile testing device worn in a backpack in order to test children during their natural movement habits, namely, running outdoors. A standard cardiopulmonary exercise ramp test on a cycle ergometer was performed by a group of twenty 7-10-year-old children. The results were compared with a self-paced incremental running test performed using a mobile cardiopulmonary exercise measuring device in an outdoor park. The children were able to reach significantly higher values for most of the cardiopulmonary exercise variables during the outdoor test and higher. Whereas a plateau in [Formula: see text] was reached by 25% of the children during the outdoor test, only 75% were able to reach a reasonable VT2, let alone [Formula: see text], during the bicycle test. The heart rate at VT1, the O2-pulse, and the OUES were comparable between both tests. OUES was also positively correlated with [Formula: see text] in both tests. Testing children outdoors using a mobile cardiopulmonary exercise unit represents an alternative to standard exercise testing, but without the added problems of exercise equipment like treadmills or bicycles. It allows for individualized exercise testing with the aim of standardized testing durations instead of standardized testing protocols. The running speeds determined during the outdoor tests may then be used to develop age-adapted testing protocols for treadmill testing.

The Effects of Aerobic Exercise on N-terminal Pro-B-type Natriuretic Peptide and Cardiopulmonary Function in Patients With Heart Failure: A Meta-Analysis of Randomised Clinical Trials.

BACKGROUND: Aerobic exercise (AEx) improves outcomes in heart failure (HF). N-terminal pro B-type natriuretic peptide (NT-pro-BNP) is a prognosticator in HF. There are few data on the association of AEx, NT-pro-BNP, and cardiopulmonary function; hence, robust evidence is needed. The aim of this study was to measure the effects of AEx on NT-pro-BNP levels and cardiopulmonary function in HF. METHOD: Databases (Pubmed, EMBASE, Medline, Cochrane Central Registry, and Scopus) were systematically searched for randomised controlled trials (RCTs) that assessed the association of AEx with NT-pro-BNP and cardiopulmonary function (VE/VCO2 slope, peak VO2, maximal workload, and left ventricular ejection fraction [LVEF]) in HF. RevMan 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, 2014) was used to produce forest plots, and the random-effect model was applied with the effects measure of weighted mean differences (WMD) and 95% confidence interval (CI). RESULTS: Thirteen (13) RCTs recruited 1,503 patients and 1,494 controls. Aerobic exercise was significant in lowering NT-pro-BNP (pg/mL) compared with control group (WMD=-741.69, 95% CI -993.10 to -490.27 [p<0.00001; I2=63%]). VE/VCO2 slope was also significantly reduced (WMD=-3.57, 95% CI -6.48 to -0.67 [p=0.02; I2=97%]). Peak VO2 (mL/kg/min) significantly improved (WMD=3.68, 95% CI 2.39-4.96 [p<0.00001; I2=96%]). Maximal workload (watt) significantly increased following AEx (WMD=22.80, 95% CI 18.44-27.17 [p<0.00001; I2=78%]). Furthermore, there was a significant enhancement of LVEF (%) in the AEx group (WMD=2.42, 95% CI 0.64-4.19 [p=0.008; I2=71%]). CONCLUSIONS: Aerobic exercise improves the NT-pro-BNP, ventilatory efficiency, aerobic capacity, maximal workload, and the left ventricular function in patients with HF.