Accurate Prediction Equations for Ventilatory Thresholds in Cardiometabolic Disease When Gas Exchange Analysis is Unavailable: Development and Validation.

AIMS: To develop and validate equations predicting heart rate (HR) at the first and second ventilatory thresholds (VTs) and an optimized range-adjusted prescription for patients with cardiometabolic disease (CMD). To compare their performance against guideline-based exercise intensity domains. METHODS: Cross-sectional study involving 2,868 CMD patients from nine countries. HR predictive equations for first and second VTs (VT1, VT2) were developed using multivariate linear regression with 975 cycle-ergometer cardiopulmonary exercise tests (CPET). 'Adjusted' percentages of peak HR (%HRpeak) and HR reserve (%HRR) were derived from this group. External validation with 1,893 CPET (cycle-ergometer or treadmill) assessed accuracy, agreement, and reliability against guideline-based %HRpeak and %HRR prescriptions using mean absolute percentage error (MAPE), Bland-Altman analyses, intraclass correlation coefficients (ICC). RESULTS: HR predictive equations (R²: 0.77 VT1, 0.88 VT2) and adjusted %HRR (VT1: 42%, VT2: 77%) were developed. External validation demonstrated superiority over widely used guideline-directed intensity domains for %HRpeak and %HRR. The new methods showed consistent performance across both VTs with lower MAPE (VT1: 7.1%, VT2: 5.0%), 'good' ICC for VT1 (0.81, 0.82) and 'excellent' for VT2 (0.93). Guideline-based exercise intensity domains had higher MAPE (VT1: 6.8%-21.3%, VT2: 5.1%-16.7%), 'poor' to 'good' ICC for VT1, and 'poor' to 'excellent' for VT2, indicating inconsistencies related to specific VTs across guidelines. CONCLUSION: Developed and validated HR predictive equations and the optimized %HRR for CMD patients for determining VT1 and VT2 outperformed the guideline-based exercise intensity domains and showed ergometer interchangeability. They offer a superior alternative for prescribing moderate intensity exercise when CPET is unavailable.

Equations to predict heart rate at ventilatory thresholds were developed and externally validated, offering a new perspective when a cardiopulmonary exercise test is unavailable to accurately determine the aerobic exercise intensity domains. Additionally, an adjusted range for exercise intensity prescription based on the percentage of heart rate reserve (%HRR) was provided, utilizing a large sample from eight countries. The proposed equations and the range-adjusted %HRR significantly outperformed the guideline-directed methods for determining exercise intensity, exhibiting higher accuracy, agreement, and reliability. Exercise intensity prescription based on the percentage of heart rate peak showed higher errors, raising concerns about its clinical applicability. Our study may enhance the efficacy of exercise training and physical activity advice when gas exchange analysis is unavailable, potentially leading to improved clinical outcomes, even in low-resource settings. Employing these approaches in research could facilitate more tailored and consistent interventions, introducing a contemporary perspective for studies comparing exercise intensity prescriptions.

Six years of demography data for 11 reef coral species.

Scleractinian corals are colonial animals with a range of life-history strategies, making up diverse species assemblages that define coral reefs. We tagged and tracked ~30 colonies from each of 11 species during seven trips spanning 6 years (2009-2015) to measure their vital rates and competitive interactions on the reef crest at Trimodal Reef, Lizard Island, Australia. Pairs of species were chosen from five growth forms in which one species of the pair was locally rare (R) and the other common (C). The sampled growth forms were massive (Goniastrea pectinata [R] and G. retiformis [C]), digitate (Acropora humilis [R] and A. cf. digitifera [C]), corymbose (A. millepora [R] and A. nasuta [C]), tabular (A. cytherea [R] and A. hyacinthus [C]) and arborescent (A. robusta [R] and A. intermedia [C]). An extra corymbose species with intermediate abundance, A. spathulata was included when it became apparent that A. millepora was too rare on the reef crest, making the 11 species in total. The tagged colonies were visited each year in the weeks prior to spawning. During visits, two or more observers each took two or three photographs of each tagged colony from directly above and on the horizontal plane with a scale plate to track planar area. Dead or missing colonies were recorded and new colonies tagged to maintain ~30 colonies per species throughout the 6 years of the study. In addition to tracking tagged corals, 30 fragments were collected from neighboring untagged colonies of each species for counting numbers of eggs per polyp (fecundity); and fragments of untagged colonies were brought into the laboratory where spawned eggs were collected for biomass and energy measurements. We also conducted surveys at the study site to generate size structure data for each species in several of the years. Each tagged colony photograph was digitized by at least two people. Therefore, we could examine sources of error in planar area for both photographers and outliners. Competitive interactions were recorded for a subset of species by measuring the margins of tagged colony outlines interacting with neighboring corals. The study was abruptly ended by Tropical Cyclone Nathan (Category 4) that killed all but nine of the more than 300 tagged colonies in early 2015. Nonetheless, these data will be of use to other researchers interested in coral demography and coexistence, functional ecology, and parametrizing population, community, and ecosystem models. The data set is not copyright restricted, and users should cite this paper when using the data.

Impacto da COVID-19 nos Programas de Reabilitação Cardiovascular no Brasil: Um Estudo Transversal Baseado em uma Pesquisa Online / Impact of COVID-19's on Cardiovascular Rehabilitation Programs in Brazil: An Online Survey-Based Cross-Sectional Study

Resumo Fundamento A pandemia da COVID-19 teve um impacto sobre os programas de reabilitação cardiovasculares (RC) no Brasil. Objetivos Descrever características dos programas de RC no Brasil, os impactos da primeira onda epidemiológica da COVID-19 (primeiros 60 dias) sobre os programas, e apresentar as iniciativas usadas para superar esses impactos. Métodos Este estudo transversal e retrospectivo usou um questionário online específico. Os participantes eram coordenadores de programas de RC. As variáveis foram apresentadas por região geográfica do Brasil, como as seguintes categorias: característica demográficas, clínicas e operacionais. O nível de significância estatística foi definido em 5%. Resultados Cinquenta e nove programas de RC atendiam 5349 pacientes, dos quais somente 1817 eram pacientes após eventos cardiovasculares agudos, o que correspondia a 1,99% dos pacientes internados no mês anterior à pesquisa (n=91.231). O maior impacto foi a suspensão das atividades presenciais, o que ocorreu de maneira similar em áreas com as taxas mais altas e áreas com as taxas mais baixas de COVID-19 no período. Quarenta e quatro (75%) programas foram interrompidos de forma breve, e três (5%) foram encerrados. Todos os 42 programas que já utilizavam estratégias de reabilitação remota notaram aumento substancial nas atividades, baseadas principalmente no uso da mídia e chamadas por vídeo. Somente três (5%) consideraram seguro atender pacientes durante os primeiros 60 dias. Conclusões Houve redução no número de programas de RC devido a pandemia da COVID-19. Atividades de telerreabilitação aumentaram durante os primeiros dois meses da pandemia da COVID-19, mas que não foi suficiente para superar a redução nas atividades dos programas de RC no Brasil.

Abstract Background The COVID-19 pandemic had an impact on cardiovascular rehabilitation (CR) programs in Brazil. Objectives To describe the characteristics of CR programs in Brazil, the impacts of the first epidemiological wave of COVID-19 (first 60 days) on the programs and present the initiatives used to overcome the impacts. Method This cross-sectional and retrospective study utilized a specific online survey. Participants were coordinators of CR programs. Variables were presented by Brazilian geographic region and as the following categories: demographic, clinical and operational characteristics. The significance level for statistical analysis was set at 5%. Results Fifty-nine CR programs were responsible for 5,349 patients, of which only 1,817 were post-acute cardiovascular events, which corresponded to 1.99% of hospitalized patients in the month prior to the survey (n=91,231). The greatest impact was the suspension of on-site activities, which occurred similarly in areas with the highest and the lowest rates of COVID-19 in the period. Forty-five programs (75%) were shortly interrupted, while three (5%) were ended. All 42 programs that already used remote rehabilitation strategies noticed a substantial increase in activities, based primarily on the use of media and video calling. Only three (5%) considered safe to see patients during the first 60 days. Conclusions There was a reduction in the number of CR programs with the COVID-19 pandemic. Telerehabilitation activities increased during the first two months of the COVID-19 pandemic, but this was not enough to overcome the reduction in CR program activities across Brazil.

Frailty in Acute and Chronic Coronary Syndrome Patients Entering Cardiac Rehabilitation.

Worldwide population ageing is partly due to advanced standard of care, leading to increased incidence and prevalence of geriatric syndromes such as frailty and disability. Hence, the age at the onset of acute coronary syndromes (ACS) keeps growing as well. Moreover, ageing is a risk factor for both frailty and cardiovascular disease (CVD). Frailty and CVD in the elderly share pathophysiological mechanisms and associated conditions, such as malnutrition, sarcopenia, anemia, polypharmacy and both increased bleeding/thrombotic risk, leading to a negative impact on outcomes. In geriatric populations ACS is associated with an increased frailty degree that has a negative effect on re-hospitalization and mortality outcomes. Frail elderly patients are increasingly referred to cardiac rehabilitation (CR) programs after ACS; however, plans of care must be tailored on individual's clinical complexity in terms of functional capacity, nutritional status and comorbidities, cognitive status, socio-economic support. Completing rehabilitative intervention with a reduced frailty degree, disability prevention, improvement in functional state and quality of life and reduction of re-hospitalization are the goals of CR program. Tools for detecting frailty and guidelines for management of frail elderly patients post-ACS are still debated. This review focused on the need of an early identification of frail patients in elderly with ACS and at elaborating personalized plans of care and secondary prevention in CR setting.

Frailty is highly prevalent in specific cardiovascular diseases and females, but significantly worsens prognosis in all affected patients: A systematic review.

Cardiologists are more often confronted with older (>60 years) cardiovascular disease (CVD) patients. These patients have particular needs in clinical care because, for example, of frailty. However, it remains to be established what is the prevalence of frailty in different CVD's and how it relates to mortality. In this systematic review studies were included if they: (i) examined subjects (men and women) aged ≥60 years who suffered from any CVD with or without cardiac surgery, (ii.) examined the presence of frailty with a well-defined frailty tool and (iii.) reported prevalence rates of frailty. From thirty studies comprising 96.841 participants, it is found that 1. Frailty is highly common in older patients with CVD (in particular in females (approximately 1.6 times more than in males), in heart failure (up to 80 % of patients) and aortic valve disease (up to 74 % of patients)), and 2. Frailty is related to a 2.5-3.5-fold elevated mortality risk, even in patients with less severe CVD (e.g. percutaneous coronary intervention). Moreover, there is a lack of consistency on how to assess frailty as up to 20 different tools/assessment batteries are currently used. It is concluded that frailty should be assessed in all older CVD patients in a uniform manner to enhance clinical care and outcomes.

Towards Optimized Care After Bariatric Surgery by Physical Activity and Exercise Intervention: a Review.

Although there is growing evidence on the importance of physical activity and exercise intervention after bariatric surgery, it remains to be clarified as to why and how post-operative exercise intervention should be implemented. In this narrative and practically oriented review, it is explained why exercise interventions and physical activity are important after bariatric surgery, how to prescribe exercise and monitor physical activity and how and when physical fitness, muscle strength, fat (-free) mass and bone mineral density could be assessed during follow-up. It is suggested that the inclusion of physical activity and exercise training in the clinical follow-up trajectory could be of great benefit to bariatric surgery patients, since it leads to greater improvements in body composition, bone mineral density, muscle strength and physical fitness.

Muscle wasting after coronary artery bypass graft surgery: impact on post-operative clinical status and effect of exercise-based rehabilitation.

Background: Coronary artery bypass graft (CABG) surgery is known to induce significant muscle wasting. It remains to be investigated whether muscle wasting after CABG surgery relates to a worse clinical status at entry of rehabilitation and exercise-based rehabilitation remediates such muscle wasting.Design: Prospective observational study.Methods: In 21 males, changes in lean tissue mass (LTM) after CABG surgery were assessed and during a 12-week endurance exercise-based rehabilitation intervention. Changes in blood parameters and cardiopulmonary exercise capacity were assessed, and relations with changes in LTM were analysed.Results: LTM decreased by -1.9 ± 2.5 kg (p < .05) within 3 weeks after CABG surgery: greater LTM loss related to a lower ventilatory threshold at entry of rehabilitation (r = 0.58-0.61, p < .05). LTM was fully restored (+2.1 ± 2.4 kg, p < .05) during rehabilitation.Conclusion: In males, CABG-induced LTM reduction was associated with a worse aerobic exercise tolerance at entry of rehabilitation, but this LTM reduction was fully remediated by endurance exercise-based rehabilitation.

Endurance Exercise Intervention Is Beneficial to Kidney Function in a Rat Model of Isolated Abdominal Venous Congestion: a Pilot Study.

In this study, the effects of moderate intense endurance exercise on heart and kidney function and morphology were studied in a thoracic inferior vena cava constricted (IVCc) rat model of abdominal venous congestion. After IVC surgical constriction, eight sedentary male Sprague-Dawley IVCc rats (IVCc-SED) were compared to eight IVCc rats subjected to moderate intense endurance exercise (IVCc-MOD). Heart and kidney function was examined and renal functional reserve (RFR) was investigated by administering a high protein diet (HPD). After 12 weeks of exercise training, abdominal venous pressure, indices of body fat content, plasma cystatin C levels, and post-HPD urinary KIM-1 levels were all significantly lower in IVCc-MOD versus IVCc-SED rats (P < 0.05). RFR did not differ between both groups. The implementation of moderate intense endurance exercise in the IVCc model reduces abdominal venous pressure and is beneficial to kidney function.

The effect of minimally invasive surgical aortic valve replacement on postoperative pulmonary and skeletal muscle function.

NEW FINDINGS: What is the central question of this study? How does surgical aortic valve replacement affect cardiopulmonary and muscle function during exercise? What is the main finding and its importance? Early after the surgical replacement of the aortic valve a significant decline in pulmonary function was observed, which was followed by a decline in skeletal muscle function in the subsequent weeks of recovery. These date reiterate, despite restoration of aortic valve function, the need for a tailored rehabilitation programme for the respiratory and peripheral muscular system. ABSTRACT: Suboptimal post-operative improvements in functional capacity are often observed after minimally invasive aortic valve replacement (mini-AVR). It remains to be studied how AVR affects the cardiopulmonary and skeletal muscle function during exercise to explain these clinical observations and to provide a basis for improved/tailored post-operative rehabilitation. Twenty-two patients with severe aortic stenosis (AS) (aortic valve area (AVA) <1.0 cm²) were pre-operatively compared to 22 healthy controls during submaximal constant-workload endurance-type exercise for oxygen uptake ( V̇O2 ), carbon dioxide output ( V̇CO2 ), respiratory gas exchange ratio, expiratory volume ( V̇E ), ventilatory equivalents for O2 ( V̇E / V̇O2 ) and CO2 ( V̇E / V̇CO2 ), respiratory rate (RR), tidal volume (Vt ), heart rate (HR), oxygen pulse ( V̇O2 /HR), blood lactate, Borg ratings of perceived exertion (RPE) and exercise-onset V̇O2 kinetics. These exercise tests were repeated at 5 and 21 days after AVR surgery (n = 14), along with echocardiographic examinations. Respiratory exchange ratio and ventilatory equivalents ( V̇E / V̇O2 and V̇E / V̇CO2 ) were significantly elevated, V̇O2 and V̇O2 /HR were significantly lowered, and exercise-onset V̇O2 kinetics were significantly slower in AS patients vs. healthy controls (P < 0.05). Although the AVA was restored by mini-AVR in AS patients, V̇E / V̇O2 and V̇E / V̇CO2 further worsened significantly within 5 days after surgery, accompanied by elevations in Borg RPE, V̇E and RR, and lowered Vt . At 21 days after mini-AVR, exercise-onset V̇O2 kinetics further slowed significantly (P < 0.05). A decline in pulmonary function was observed early after mini-AVR surgery, which was followed by a decline in skeletal muscle function in the subsequent weeks of recovery. Therefore, a tailored rehabilitation programme should include training modalities for the respiratory and peripheral muscular system.

Western diet given to healthy rats mimics the human phenotype of diabetic cardiomyopathy.

Diabetes mellitus (DM) is a major problem worldwide. Within this patient group, cardiovascular diseases are the biggest cause of morbidity and mortality. Diabetic cardiomyopathy (DCM) is defined as diabetes-associated structural and functional changes in the myocardium, not directly attributable to other confounding factors such as coronary artery disease or hypertension. Pathophysiology of DCM remains unclear due to a lack of adequate animal models reflecting the current pandemic of diabetes, associated with a high increased sugar intake and the 'Western' lifestyle. The aim of this study was to develop an animal model mimicking this 'Western' lifestyle causing a human-like phenotype of DCM. Twenty-four Sprague-Dawley rats were randomly assigned into a normal or a 'Western' diet group for 18 weeks. Glucose and insulin levels were measured with an OGTT. Heart function was assessed by echocardiography and hemodynamic measurements in vivo. Cardiac fibrosis and inflammation were investigated in vitro. 'Western' diet given to healthy rats for 18 weeks induced hyperglycemia together with increased AGEs levels, insulin levels and hypertriglyceridemia. Heart function was altered with increased end-diastolic pressure, left ventricle hypertrophy. Changes in vivo were associated with increased collagen deposition and increased PAI-1 levels in the heart. High-sugar diet or 'Western' diet causes T2DM and the hallmarks of DCM in rats, reflecting the phenotype of the disease seen in patients. Using this new model of T2DM with DCM might open new insight in understanding the pathophysiology of DCM and on a long term, test targeted therapies for T2DM with DCM patients.

Selective abdominal venous congestion to investigate cardiorenal interactions in a rat model.

Abdominal congestion may play an important role in the cardiorenal syndrome and has been demonstrated to drive disease progression. An animal model for abdominal congestion, without other culprit mechanisms that are often present in patients such as low cardiac output or chronic kidney disease, might be interesting to allow a better study of the pathophysiology of the cardiorenal syndrome. The objective of this study was to develop a clinically relevant and valid rat model with abdominal venous congestion and without pre-existing heart and/or kidney dysfunction. To do so, a permanent surgical constriction (20 Gauge) of the thoracic inferior vena cava (IVC) was applied in male Sprague Dawley rats (IVCc, n = 7), which were compared to sham-operated rats (SHAM, n = 6). Twelve weeks after surgery, abdominal venous pressure (mean: 13.8 vs 4.9 mmHg, p < 0.01), plasma creatinine (p < 0.05), plasma cystatin c (p < 0.01), urinary albumin (p < 0.05), glomerular surface area (p < 0.01) and width of Bowman's space (p < 0.05) of the IVCc group were significantly increased compared to the SHAM group for a comparable absolute body weight between groups (559 vs 530g, respectively, p = 0.73). Conventional cardiac echocardiographic and hemodynamic parameters did not differ significantly between both groups, indicating that cardiac function was not compromised by the surgery. In conclusion, we demonstrate that constriction of the thoracic IVC in adult rats is feasible and significantly increases the abdominal venous pressure to a clinically relevant level, thereby inducing abdominal venous congestion.

Characteristics of structured physical training currently provided in cardiac patients: insights from the Exercise Training in Cardiac Rehabilitation (ETCR) Italian survey.

BACKGROUND: Uncertainty exists about current delivery levels of exercise training (ET) during Cardiac Rehabilitation (CR) programmes. AIM OF THE STUDY: To evaluate ET modalities in the real world of CR facilities in Italy. METHODS: This was an observational survey of aggregate data, collected from CR facilities on a voluntary basis. Snapshots of a single working day at a local site were made, in terms of characteristics of patients and ET programmes delivered. RESULTS. Overall, 612 patients from 26 CR units were included, with an in-patient vs. out-patient ratio of 3:1. Coronary artery disease (57.6%), heart failure (20.3%), and valve disease/surgery (22.1%) were the most represented target groups. The prevalence of endurance continuous training, interval training, and resistance/strength training was 66.7%, 11.1%, and 9.0%; other non-aerobic endurance and non-resistance training modalities such as respiratory muscle training and calisthenics were reported in 39.9% and 42.9% of cases respectively. Workloads for endurance exercise training were determined by cardiopulmonary test, conventional 12-leads ECG exercise testing, 6min-walking test, theoretical determination of heart rate, and rating of perceived exertion in 9%, 8%, 27%, 9%, and 40% of cases respectively. The average duration of the programmes (on an intention to treat basis) was 25 sessions of 42±11  minutes, with a frequency of >4 sessions/week in 67% of patients. CONCLUSIONS: Despite advances in CR interventions, there is a significant need for improvement of functional evaluation and exercise training prescription, and consideration of a wider range of training modalities in Italy. .

Circulating classical monocytes are associated with CD11c+ macrophages in human visceral adipose tissue.

Immune cell accumulation in adipose tissue (AT) is associated with the development of AT inflammation, resulting in metabolic dysfunction. Circulating immune cell patterns may reflect immune cell accumulation in expanding AT. However, data linking human leukocytes in blood and AT is lacking. We investigated whether blood immune cell populations are associated with their counterparts in subcutaneous (scAT) or visceral AT (vAT). Flow cytometry was performed on blood, scAT and vAT from 16 lean and 29 obese men. Circulating natural killer (NK)-cells, classical monocytes and nonclassical monocytes were higher in obese individuals. vAT, but not scAT, of obese individuals contained more inflammatory CD11c+ "M1" macrophages and NK cells compared to lean individuals. Blood classical monocytes were associated with CD11c+ macrophages in vAT but not scAT. This association was unrelated to expression of the adhesion molecules CD11b and CD11c or of the chemokine receptor CX3CR1 on these monocytes. Other AT immune cells were not associated with their respective counterparts in blood. Finally, CD11c+ macrophages and CD4+ T-cells in vAT were associated with their counterparts in scAT. In conclusion, blood classical monocytes reflect CD11c+ macrophages in vAT.

High Intensity Aerobic and Resistance Exercise Can Improve Glucose Tolerance in Persons With Multiple Sclerosis: A Randomized Controlled Trial.

INTRODUCTION: The prevalence of impaired glucose tolerance (IGT) is higher in persons with multiple sclerosis (MS) compared to healthy controls, indicating metabolic deficits that may increase comorbidity. In other populations, IGT can, at least partly, be reversed by intense physical exercise, but this is never investigated before in MS. AIM: To investigate the effect of high intensity aerobic and resistance training on glucose tolerance and skeletal muscle GLUT4 content in MS. METHODS: Thirty-four persons with MS (aged 45 ± 3 years, EDSS 2.5 ± 1.07) were randomized into three groups, including a (1) sedentary control group (SED, n = 11), (2) 12-week high intensity interval plus resistance training group (HITR, n = 12), or (3) 12-week high intensity continuous aerobic training plus resistance training group (HCTR, n = 11). Before and after 12 weeks, glucose tolerance and skeletal muscle GLUT4 content were determined by an oral glucose tolerance test and analysis of a m.vastus lateralis biopsy, respectively. RESULTS: There were no significant changes for subjects of SED. From pre- to post-intervention, total area under the glucose curve (tAUC) decreased significantly in both HITR (-6.9 ± 6.2%) and HCTR (-11.0 ± 7.7%) (P < 0.05). Insulin tAUC decreased (-12.3 ± 14.7%) within HCTR and muscle GLUT4 content increased (+6.6 ± 4.5%) in HITR. CONCLUSION: Twelve weeks of high intensity aerobic exercise in combination with resistance training improved glucose tolerance in persons with MS.

Compromised Cardiopulmonary Exercise Capacity in Patients Early After Endoscopic Atraumatic Coronary Artery Bypass Graft: Implications for Rehabilitation.

OBJECTIVE: The purpose of this work was to test the hypothesis that cardiopulmonary exercise tolerance is better preserved early after endoscopic atraumatic coronary artery bypass graft (endo-ACAB) surgery versus coronary artery bypass graft (CABG) surgery. DESIGN: Twenty endo-ACAB surgery patients, 20 CABG surgery patients, and 15 healthy subjects executed a maximal cardiopulmonary exercise test, with assessment and comparison of cycling power output, O2 uptake, CO2 output, respiratory gas exchange ratio, end-tidal O2 and CO2 pressures, equivalents for O2 uptake and CO2 output, heart rate, O2 pulse, expiratory volume, tidal volume, respiratory rate, at peak exercise and ventilatory threshold. In patients, forced expiratory volume and forced vital capacity were measured. RESULTS: Oxygen uptake, CO2 output, expiratory and tidal volume, equivalents for O2 uptake and CO2 output, end-tidal O2 and CO2 pressures at peak exercise (matched peak respiratory gas exchange ratio between patient groups), and ventilatory threshold were significantly worse in patients versus healthy controls (P < 0.05; observed power, >0.80). All these parameters, and lung function, were, however, comparable between CABG and endo-ACAB surgery patients (P > 0.10). CONCLUSIONS: Exercise tolerance and ventilatory function during exercise seems, in contrast to expectation, equally compromised early after endo-ACAB surgery as opposed to after CABG surgery. These data may signify the need for exercise-based rehabilitation intervention early after endo-ACAB surgery.

Altered gas-exchange at peak exercise in obese adolescents: implications for verification of effort during cardiopulmonary exercise testing.

BACKGROUND: Cardiopulmonary exercise testing is advised ahead of exercise intervention in obese adolescents to assess medical safety of exercise and physical fitness. Optimal validity and reliability of test results are required to identify maximal exercise effort. As fat oxidation during exercise is disturbed in obese individuals, it remains an unresolved methodological issue whether the respiratory gas exchange ratio (RER) is a valid marker for maximal effort during exercise testing in this population. METHODS: RER during maximal exercise testing (RERpeak), and RER trajectories, was compared between obese and lean adolescents and relationships between RERpeak, RER slope and subject characteristics (age, gender, Body Mass Index [BMI], Tanner stage, physical activity level) were explored. Thirty-four obese (BMI: 35.1±5.1 kg/m²) and 18 lean (BMI: 18.8±1.9 kg/m²) adolescents (aged 12-18 years) performed a maximal cardiopulmonary exercise test on bike, with comparison of oxygen uptake (VO2), heart rate (HR), expiratory volume (VE), carbon dioxide output (VCO2), and cycling power output (W). RESULTS: RERpeak (1.09±0.06 vs. 1.14±0.06 in obese vs. lean adolescents, respectively) and RER slope (0.03±0.01 vs. 0.05±0.01 per 10% increase in VO2, in obese vs. lean adolescents, respectively) was significantly lower in obese adolescents, and independently related to BMI (P<0.05). Adjusted for HRpeak and VEpeak, RERpeak and RER slope remained significantly lower in obese adolescents (P<0.05). RER trajectories (in relation to %VO2peak and %Wpeak) were significantly different between groups (P<0.001). CONCLUSIONS: RERpeak is significantly lowered in obese adolescents. This may have important methodological implications for cardiopulmonary exercise testing in this population.

Changes in structural and metabolic muscle characteristics following exercise-based interventions in patients with COPD: a systematic review.

Patients with COPD suffer from lower-limb muscle dysfunction characterized by lower muscle oxidative capacity and muscle mass. Exercise-based training is expected to attenuate lower-limb intramuscular characteristics, but a detailed systematic approach to review the available evidence has not been performed yet. PUBMED and PEDro databases were searched. Twenty-five studies that implemented an exercise-based training program (aerobic and/or resistance training, high intensity interval training, electrical or magnetic stimulation) and reported muscle biopsy data of patients with COPD were critically appraised. The coverage of results includes changes in muscle structure, muscle protein turnover regulation, mitochondrial enzyme activity, oxidative and nitrosative stress, and inflammation after exercise-based training interventions. Study design and training modalities varied among studies, which partly explains the observed heterogeneous response in muscle characteristics. Gaps in the current knowledge are identified and recommendations for future research are made to enhance our knowledge on exercise training effects in patients with COPD.

Reduction in pulmonary function after CABG surgery is related to postoperative inflammation and hypercortisolemia.

UNLABELLED: Pulmonary function is significantly reduced in the acute phase after coronary artery bypass graft (CABG) surgery. Because pulmonary function partly depends on respiratory muscle strength, we studied whether reductions in pulmonary function are related to postoperative alterations in circulatory factors that affect muscle protein synthesis. METHODS: Slow vital capacity (SVC) was assessed in 22 subjects before and 9 ± 3 days after CABG surgery. Blood testosterone, cortisol, insulin-like growth factor-1 (IGF-1), growth hormone, sex-hormone binding globulin (SHBG), glucose, insulin, c-peptide, c-reactive protein (CRP) content, and free androgen index, cortisol/testosterone ratio, HOMA-IR index were assessed before surgery and during the first three days after surgery. Intubation, surgery time and cumulative chest tube drainage were measured. Correlations between changes in SVC and blood parameters after surgery or subject characteristics were studied. This was a prospective observational study. RESULTS: After CABG surgery SVC decreased by 37 ± 18% (P < 0.01). Free androgen index, blood SHBG, testosterone and IGF-1 content decreased, while HOMA-IR index, cortisol/testosterone ratio, blood growth hormone, insulin and CRP content increased (P < 0.0025) in the first three days after surgery. Decrease in SVC was independently (P < 0.05) related to higher preoperative SVC (SC ß = 0.66), and greater increase in blood cortisol (SC ß = 0.54) and CRP (SC ß = 0.37) content after surgery. CONCLUSIONS: Larger reductions in pulmonary function after CABG surgery are present in patients experiencing greater postoperative increases in blood CRP and cortisol levels. Decrements in pulmonary function after CABG surgery are, at least in part, thus related to alterations in circulatory factors that affect muscle protein synthesis.

Medium-Term Effectiveness of a Comprehensive Internet-Based and Patient-Specific Telerehabilitation Program With Text Messaging Support for Cardiac Patients: Randomized Controlled Trial.

BACKGROUND: Cardiac telerehabilitation has been introduced as an adjunct or alternative to conventional center-based cardiac rehabilitation to increase its long-term effectiveness. However, before large-scale implementation and reimbursement in current health care systems is possible, well-designed studies on the effectiveness of this new additional treatment strategy are needed. OBJECTIVE: The aim of this trial was to assess the medium-term effectiveness of an Internet-based, comprehensive, and patient-tailored telerehabilitation program with short message service (SMS) texting support for cardiac patients. METHODS: This multicenter randomized controlled trial consisted of 140 cardiac rehabilitation patients randomized (1:1) to a 24-week telerehabilitation program in combination with conventional cardiac rehabilitation (intervention group; n=70) or to conventional cardiac rehabilitation alone (control group; n=70). In the telerehabilitation program, initiated 6 weeks after the start of ambulatory rehabilitation, patients were stimulated to increase physical activity levels. Based on registered activity data, they received semiautomatic telecoaching via email and SMS text message encouraging them to gradually achieve predefined exercise training goals. Patient-specific dietary and/or smoking cessation advice was also provided as part of the telecoaching. The primary endpoint was peak aerobic capacity (VO2 peak). Secondary endpoints included accelerometer-recorded daily step counts, self-assessed physical activities by International Physical Activity Questionnaire (IPAQ), and health-related quality of life (HRQL) assessed by the HeartQol questionnaire at baseline and at 6 and 24 weeks. RESULTS: Mean VO2 peak increased significantly in intervention group patients (n=69) from baseline (mean 22.46, SD 0.78 mL/[min*kg]) to 24 weeks (mean 24.46, SD 1.00 mL/[min*kg], P<.01) versus control group patients (n=70), who did not change significantly (baseline: mean 22.72, SD 0.74 mL/[min*kg]; 24 weeks: mean 22.15, SD 0.77 mL/[min*kg], P=.09). Between-group analysis of aerobic capacity confirmed a significant difference between the intervention group and control group in favor of the intervention group (P<.001). At 24 weeks, self-reported physical activity improved more in the intervention group compared to the control group (P=.01) as did the global HRQL score (P=.01). CONCLUSIONS: This study showed that an additional 6-month patient-specific, comprehensive telerehabilitation program can lead to a bigger improvement in both physical fitness (VO2 peak) and associated HRQL compared to center-based cardiac rehabilitation alone. These results are supportive in view of possible future implementation in standard cardiac care.