Cardiopulmonary Exercise Testing Research Articles

Investigation of exertional dyspnoea by cardiopulmonary exercise testing with continuous laryngoscopy

ObjectivesAbnormal breathlessness at maximal exercise may be caused by a range of conditions, including exercise-induced bronchospasm, breathing pattern disorder, or exercise-induced laryngeal obstruction. These three disorders may not be detected on standard cardiopulmonary exercise testing. The aim of this study was to describe diagnostic outcomes of an expanded protocol during cardiopulmonary exercise testing. DesignRetrospective cohort study. MethodsPatients presenting with abnormal breathlessness on maximal exercise underwent continuous laryngoscopy with cardiopulmonary exercise testing on a stationary cycle ergometer. Breathing pattern disorder was evaluated by video and ventilatory data. Pre- and post-exercise spirometry was performed. Results24 adult patients were evaluated; 10 were professional athletes. Mean age was 40 years (range 18–73). Nine of 24 (38 %) were diagnosed with exercise-induced laryngeal obstruction and referred for speech pathology. Six of these had supraglottic exercise-induced laryngeal obstruction; all were aged <30 years; 5/6 were professional athletes. One patient had breathing pattern disorder and was referred for physiotherapy; one had exercise-induced bronchospasm, requiring escalation of asthma medication; one had muscle tension dysphonia resulting in referral to an otolaryngologist who administered a laryngeal injection of botulinum toxin. A further four patients had unexplained lower maximal oxygen consumption with cardiac limitation and were referred for further cardiac investigation. ConclusionsIn patients reporting abnormal breathlessness at maximal exercise, this expanded exercise protocol provided diagnostic information in 66.7 % cases which contributed to further personalised management.

Oxygen uptake efficiency slope at anaerobic threshold can predict peak VO2 in adult congenital heart disease

IntroductionAssessment of exercise capacity by cardiopulmonary exercise testing (CPET) in adults with congenital heart disease (CHD) is important for prognostication and preoperative assessment. Peak oxygen uptake (PVO2) is used commonly, but can be challenging due to the difficulties of undertaking maximal CPET testing in this population. We explored whether oxygen uptake efficiency slope (OUES) at ventilatory anaerobic threshold (VAT), the point during CPET at which OUES becomes strongly correlated with PVO2, and is more reliably available from submaximal CPET, can predict PVO2 in adults with CHD. MethodsWe assessed consecutive individuals who completed maximal CPET at our cardiorespiratory centre, as part of routine service review, between March 2019 and August 2021, recording data such as PVO2, VAT and OUES at various proportions of a maximal test (75 %, 90 %, 100 %, and VAT). We employed linear regression modelling to analyse the association between PVO2 and OUES at VAT, and subsequently create an equation to predict PVO2 from OUES at VAT. Parametric data are presented using Pearson's correlation coefficient and non-parametric data using Spearman's rho. ResultsWe analysed 391 individuals (177 female, age 32 ± 11 years). Mean ± SD PVO2 was 23.3 ± 6.86 ml/min/kg or 1724 ± 540 ml/min, peak VE 86.7 ± 25.4 l/min. The point of VAT as a percentage of PVO2 achieved was 66.5 ± 9.4 %, and VAT as a percentage of predicted PVO2 46.9 ± 11.4 %. PVO2 was correlated with OUES at 100 % (R = 0.91, P < .001), 90 % (R = 0.91, P < .001), 75 % (R = 0.89, P < .001) of maximum, and VAT (R = 0.83, P < .001). PVO2(ml/min) could be predicted by: (OUES at VAT)∗685.245 + (BMI [kg/m2])∗5.045 + (FEV1[l])∗223.620 – 153.205. ConclusionsOUES at VAT can be used to calculate PVO2. To our knowledge, this is the first equation using OUES at VAT to predict PVO2 in adults with CHD. In a population who may find maximal CPET difficult, this may be a useful submaximal measurement of cardiovascular fitness, and to calculate PVO2, which is commonly used in guideline-based decision making in CHD.

O97 RESPONSE TO AEROBIC TRAINING MAY DIFFER BETWEEN ELDERLY MEN AND WOMEN WITH TREATED HYPERTENSION

Background and objective. Hypertension incidence increases with aging, with expressive enhancement in women after the menopause due to the important physiological changes induced by the estrogen levels decline. Aerobic training is recommended for lowering blood pressure (BP) in men and women with hypertension. However, the possible gender-related differences in training responses have been poorly investigated, especially in elderly patients. Therefore, the objective of this study was to analyze responses to aerobic training in elderly men and women with treated hypertension. Methods: Thirty-one elderly hypertensives (15 women, 68±6ys and 16 men, 66±7ys) who were taking regular antihypertensive medication for at least 4 months participated in the study. They underwent 10 weeks of an aerobic training designed in accordance with the guidelines’ recommendations for hypertension (i.e. 3 session/week, cycle ergometer, 30-45 min, moderate intensity). Before and after the training period, peak oxygen uptake (VO2peak, cardiopulmonary exercise test), BP (auscultatory), systemic hemodynamics (CO2 rebreathing technique) and vascular function (brachial doppler ultrasound) were assessed. In each group (men and women), the training effects were evaluated using paired t-tests or Wilcoxon tests, considering p&lt;0.05 as significant. Results: Aerobic training increased aerobic capacity in both sexes (men = 20.8±4.2 vs. 21.8±4.8 ml.kg-1.min-1, p=0.04 and women = 15.3±2.6 vs. 16.4±2.3 ml.kg-1.min-1, p=0.01). In men, systolic BP and systemic vascular resistance decreased (129±13 vs. 125±12 mmHg, p=0.003 and 21.0±3.8 vs. 18.9±4.1 u, p=0.02), while flow mediated dilation increased (5.5±2.9 vs. 7.2±3.1%, p=0.01) after the training period. On the other hand, in women, none of these variables changed with the training (124±15 vs. 126±12 mmHg, p=0.92; 23.2±5.5 vs. 23.5±5.6 u, p=0.80; and 4.2±3.2 vs. 5.4±3.5%, p=0.10). The other variables assessed did not change in either group. Conclusions: The proposed aerobic training program increased aerobic capacity in both male and female elderly hypertensives, but improved BP, systemic vascular resistance, and endothelial function only in males. Key-words: aerobic training, gender, blood pressure, hypertension. Financial Support: CAPES-0001, CNPq-302309/2022-5, and FAPESP- 2022/12605-3.

The MuCAYAplus Study—Influence of Physical Activity and Metabolic Parameters on the Structure and Function of the Cardiovascular System in Young Athletes

Exercise has a significant impact on the cardiovascular (CV) health of children and adolescents, with resultant alterations in CV structure and function being evident, even at an early age. Engagement in regular, moderate physical activity (PA) is associated with long-term CV health benefits and a reduced risk of CV disease and mortality later in life. However, competitive sports often involve PA training intensities that are beyond recommended levels for young athletes, potentially leading to adverse CV outcomes. This situation emphasizes the importance of early monitoring of CV status, to prevent detrimental adaptations to intense physical exercise. The Munich Cardiovascular Adaptation in Young Athletes Study (MuCAYAplus; NCT06259617) aims to investigate the as-yet-unclear adaptations to intense exercise that occur in young athletes. The study focuses on various factors, including CV health, PA, cardiopulmonary performance, body composition, eating habits, and biochemical markers.In this longitudinal, prospective study, a sample of 250 young competitive athletes (aged 10-17 years) will undergo yearly examinations at the Institute of Preventive Pediatrics at the Technical University of Munich (TUM), over the span of 3 years. The testing protocol includes the following: anthropometric measurements; basic medical examinations; electrocardiography, with blood-pressure and pulse-wave analysis; echocardiography; sonography of the carotid artery; blood sampling for laboratory analysis; cardiopulmonary exercise testing on a bicycle ergometer; and participant completion of questionnaires regarding PA (the Motorik-Modul Longitudinal Study PA Questionnaire [MoMo-PAQ]) and nutrition.Areas that are not yet fully understood are how exercise influences cardiac and vascular remodeling during long-term exercise, and how different biochemical and metabolic parameters, body composition, and nutrition impact such adaptations. The MuCAYAplus study seeks to address these gaps in knowledge and provide comprehensive evidence on the longitudinal effects of exercise on the CV system of young athletes.

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.

Visceral adiposity: A major mediator of the relationship between epicardial adiposity and cardiorespiratory fitness in adults

Background and aimsEpicardial adiposity has been positively associated with visceral adipose tissue (VAT). Few studies have examined the association between cardiorespiratory fitness (CRF) and epicardial adiposity. Furthermore, whether this relationship was independent of VAT remains unexplored. Our purpose was to investigate the contribution of VAT in the relationships between CRF, physical activity (PA) and epicardial adipose tissue (EAT) in asymptomatic women and men. Methods and resultsWe examined the associations between EAT and VAT measured by magnetic resonance imaging, CRF measured by cardiopulmonary exercise testing, and PA assessed using pedometers and a 3-day PA journal in 239 apparently healthy adults (43 % women). Participants were compared according to EAT tertiles and CRF level in both sexes. Participants with the highest EAT level presented more VAT (p < 0.001), lower CRF (p < 0.01), and a more deteriorated cardiometabolic health score (p < 0.01) than those with the lowest EAT level. CRF was negatively associated with EAT in both sexes (p < 0.01). No significant relationship was found with PA (p = NS). Stepwise multivariable regression analyses showed that VAT explained most of the variance in EAT in women and men. Mediation analyses confirmed that VAT was a mediator of the association between CRF and EAT in both sexes. ConclusionIn women and men, VAT appears as a major mediator of the association between CRF and EAT thereby suggesting that managing VAT by improving CRF could help in the prevention of cardiometabolic disorders related to excess EAT.

Late Follow-up for a Randomized Trial of Surgical Treatment of Tricuspid Valve Regurgitation in Patients Undergoing Left Ventricular Assist Device Implantation

ObjectivesWe previously reported that concurrent tricuspid valve surgery (TVS) was not associated with a lower incidence of early RHF among patients undergoing durable LVAD implantation. This is a follow-up analysis to further define the clinical impact of concurrent TVS within 12-months of follow-up. MethodsPatients with moderate or severe TR on pre-operative echocardiography (n=71) were randomized to either LVAD implantation alone (No TVS, n=34) or with concurrent TVS (TVS, n=37). Randomization was stratified by pre-operative right ventricular dysfunction. Patients were followed for at least 12-months after surgery. The incidence of RHF was determined using INTERMACS criteria by an adjudication committee. Functional studies and repeat echocardiography were performed at 12-months. ResultsDemographics were similar between the two arms. At 12-months, the rate of moderate or severe RHF was 50.0% (No TVS) versus 51.4% (TVS). No patients developed RHF between 6- and 12-months following the procedure. Death from RHF was 5.4% (TVS) versus 8.8% (No TVS). At 12-months, there was no significant difference in TR severity between the two arms due to improvement in TR severity in the No TVS arm. On cardiopulmonary exercise testing at 12+ months, there was no significant difference in peak oxygen consumption. ConclusionsIn patients with significant pre-implant TR, the severity of TR improved over time in the LVAD implantation alone arm. By 12-months, there is no significant difference in TR severity between the two arms. This may account for the lack of difference in late clinical or functional parameters.

Impact of VO 2peak on the Clinical Outcomes of Older Patients With Coronary Heart Disease in China.

The aim of this study was to explore the role of cardiopulmonary exercise test parameters, especially peak oxygen uptake (VO 2peak ), in predicting the incidence of adverse cardiovascular events in older Chinese patients with coronary heart disease (CHD). Older patients with CHD who underwent cycle ergometer cardiopulmonary exercise test at the Cardiac Rehabilitation Clinic of Chinese PLA General Hospital from July 1, 2015 to January 31, 2020 were enrolled. The follow-up intervals were 6mo. Cox regression was used to analyze the relationship between VO 2peak and adverse cardiovascular events. Restricted cubic splines and subgroup analyses were used to observe the relationship between VO 2peak and the hazard ratio (HR) of the primary end point event (PEE), which included a composite of all-cause death, nonfatal recurrent myocardial infarction, unscheduled revascularization, and stroke. The composite end point event was the PEE combined with cardiac rehospitalization. A total of 1223 participants (mean age 68±5yr) were included. Median follow-up was 68mo. Mean VO 2peak was 16.5±4.0 mL/kg/min, and VO 2peak was an independent predictor of the PEE (HR=0.929; 95% CI, 0.891-0.970; P =.001). This association was further validated by restricted cubic spline and subgroup analyses. Peak oxygen uptake was also an independent risk factor for the composite end point event (HR=0.968; 95% CI, 0.941-0.996; P =.025). In conclusion, VO 2peak is an independent risk factor for adverse cardiovascular events in older Chinese patients with CHD, and more optimal therapy should be recommended to patients with lower VO 2peak .

Surgical treatment and outcomes of pectus arcuatum

ObjectivePectus arcuatum is a rare variant of pectus deformities that can cause varying degrees of cardiac compression. A review of the evaluation, surgical repair, and outcomes of pectus arcuatum is presented. MethodsA retrospective review of all patients undergoing surgical treatment of pectus arcuatum at a single institution was conducted between January 1, 2010, and May 31, 2024. Descriptive statistics and surgical techniques are presented. ResultsTwenty patients underwent pectus arcuatum repair (median age, 22.9 years; 55.0% men, median Haller index 2.8 [interquartile range, 1.4]) during the study period. Preoperatively, all patients were bothered by their chest appearance and symptomatic, with the most common symptoms being exercise intolerance (95.0%), shortness of breath (90.0%), and chest pain (90.0%). Preoperatively, cardiopulmonary exercise testing was performed in almost half the patients with abnormal findings (median maximum oxygen consumption, 67.0% of predicted). A hybrid approach with sternal osteotomy and minimally invasive pectus excavatum repair was utilized in 19 out of 20 cases, with 1 case requiring sternal osteotomy only. Single wedge osteotomy was sufficient in most cases (70.0%). Median intraoperative time was 3.5 hours (interquartile range, 1.2 hours). The adoption of cryoablation in 2018 significantly reduced hospital stays, from 5.0 days (interquartile range, 1.5 days) to 3.0 (interquartile range, 2.25 days) (P < .001). At follow-up, all reported cosmetic satisfaction and most reported symptom improvement. ConclusionsPectus arcuatum can be successfully repaired with a hybrid surgical approach involving sternal osteotomy and Nuss bar placement. Symptomatic patients should be considered for surgery, with postoperative improvement expected.

Young users of electronic cigarettes exhibit reduced cardiorespiratory fitness.

Electronic nicotine delivery systems, often referred to as e-cigarettes, are popular tobacco products frequently advertised as safer alternatives to traditional cigarettes despite preliminary data suggesting a potential negative cardiovascular impact. Cardiorespiratory fitness is a critical cardiovascular health marker that is diminished in individuals who consume traditional tobacco products. Whether the use of e-cigarettes impacts cardiorespiratory fitness is currently unknown. Thus, the purpose of this study was to investigate the impact of regular e-cigarette use on cardiorespiratory fitness in young healthy adults. Twenty-six users of e-cigarettes (ECU, 13 males, and 13 females; age: 24 ± 3 yr; e-cigarette usage 4 ± 2 yr) and 16 demographically matched nonusers (NU, 6 males, and 10 females; age: 23 ± 3 yr) participated in this study. Cardiorespiratory fitness was measured by peak oxygen consumption (V̇o2peak) during a cardiopulmonary exercise test. Measurements of chronotropic response, hemodynamic, oxygen extraction, and utilization were also evaluated. Our results suggest that regular users of e-cigarettes exhibited significantly lower peak oxygen consumption when compared with nonusers, even when controlled by fat-free mass and lean body mass. Hemodynamic changes were not different between both groups during exercise, whereas lower chronotropic responses and skeletal muscle oxygen utilization were observed in users of e-cigarettes. Results from the present study demonstrate that young, apparently healthy, regular users of e-cigarettes exhibit significantly reduced cardiorespiratory fitness, lower chronotropic response, and impaired skeletal muscle oxygen utilization during exercise. Overall, our findings contribute to the growing body of evidence that supports adverse effects of regular e-cigarette use on cardiovascular health.NEW & NOTEWORTHY E-cigarettes are tobacco products frequently used by youth and young adults. Little is known about the long-term health effects of their prolonged use. Results from the present study demonstrate that young, apparently healthy, regular users of e-cigarettes exhibit significantly reduced cardiorespiratory fitness, a marker of cardiovascular health and a predictor of all-cause mortality. We also identified that the young users of e-cigarettes present with lower chronotropic response and impaired skeletal muscle oxygen utilization during exercise.

Exceptional exercise capacity in a late bloomer octogenarian triathlete.

Maximal oxygen uptake (V̇O<inf>2max</inf>) gradually declines across the lifespan. However, little is known about the octogenarians. This is a knowledge gap given that individuals living >80 years old is the fastest expanding age-group world-wide. The increase in the elderly population has generated greater awareness in healthy ageing including psychosocial, physical, and cognitive domains, all of which benefit from engagement in physical activity or sport. In the present article are reported characteristics of an octogenarian man (GM), starting training for triathlon when he was 75 years old. GM performed an incremental Cardiopulmonary Treadmill-Running Exercise Test (CPX). A competitive 5-day consecutive triathlon event (sprint distance on days 1, 3, 4, 5 and Olympic distance on day 2) was monitored using an advanced smartwatch. Between 2021 and 2022, he trained for 10-to-12 hours/week, and participated in 59 and 39 competitions, respectively. The CPX showed a V̇O<inf>2max</inf> of 39.8 mL·min-1·kg-1, the 3rd highest value ever described in the literature among octogenarians and corresponding to the ≈60th percentile of 40-to-49-year-old men. During the 5-day triathlon (overall 12:15 h:min), 88% of time was spent at 77-95% of maximum heart rate (i.e., vigorous exercise intensity). In addition, GM was the 2022 Triathlon Olympic distance World Champion. The remarkably high V̇O<inf>2max</inf> and performance described herein were associated with exceptionally high exercise volume and intensity during training and competition, up to more than four times the recommended physical activity by current guidelines. These results further support the benefits of endurance exercise among octogenarians.

Lifelong physiology of a former marathon world-record holder: the pros and cons of extreme cardiac remodeling.

In a 77-year-old former world-record-holding male marathoner (2:08:33.6), this study sought to investigate the impact of lifelong intensive endurance exercise on cardiac structure, function, and the trajectory of functional capacity (determined by maximal oxygen consumption, V̇o2max) throughout the adult lifespan. As a competitive runner, our athlete (DC) reported performing up to 150-300 miles/wk of moderate-to-vigorous exercise and sustained 10-15 h/wk of endurance exercise after retirement from competition. DC underwent maximal cardiopulmonary exercise testing in 1970 (aged 27 yr), 1991 (aged 49 yr), and 2020 (aged 77 yr) to determine V̇o2max. At his evaluation in 2020, DC also underwent comprehensive cardiac assessments including resting echocardiography, and resting and exercise cardiac magnetic resonance to quantify cardiac structure and function at rest and during peak supine exercise. DC's V̇o2max showed minimal change from 27 yr (69.7 mL/kg/min) to 49 yr (68.1 mL/kg/min), although it eventually declined by 36% by the age of 77 yr (43.6 mL/kg/min). DC's V̇o2max at 77 yr, was equivalent to the 50th percentile for healthy 20- to 29-yr-old males and 2.4 times the requirement for maintaining functional independence. This was partly due to marked ventricular dilatation (left-ventricular end-diastolic volume: 273 mL), which facilitates a large peak supine exercise stroke volume (200 mL) and cardiac output (22.2 L/min). However, at the age of 78 yr, DC developed palpitations and fatigue and was found to be in atrial fibrillation requiring ablation procedures to revert his heart to sinus rhythm. Overall, this life study of a world champion marathon runner exemplifies the substantial benefits and potential side effects of many decades of intense endurance exercise.NEW & NOTEWORTHY This life study of a 77-yr-old former world champion marathon runner exemplifies the impact of lifelong high-volume endurance exercise on functional capacity (V̇o2max equivalent to a 20- to 29-yr-old), partly due to extreme ventricular remodeling that facilitates a large cardiac output during exercise despite reduced maximal heart rate. Although it is possible that this extreme remodeling may contribute to developing atrial fibrillation, the net benefits of extreme exercise throughout this athlete's lifespan favor increased health span and expected longevity.

Post-Pulmonary Embolism Phenotypes Described by Invasive Cardiopulmonary Exercise Testing

BackgroundPost pulmonary embolism (PE) dyspnea is common. Existing non-invasive studies have demonstrated that post PE dyspnea is associated with elevations in right ventricular afterload, dead space ventilation, and deconditioning. We aimed to use invasive cardiopulmonary exercise testing (iCPET) parameters in patients with post PE dyspnea to identify unique physiologic phenotypes. Research QuestionAre there distinct post pulmonary embolism dyspnea physiologic phenotypes described with iCPET? Study Design and MethodsPatients were enrolled at the time of acute PE and through our pulmonary hypertension and dyspnea clinic. ICPET was performed if there was high suspicion for pulmonary hypertension or if there was unexplained dyspnea. A hierarchical cluster analysis was performed to identify dyspnea phenotypes. ICPET parameters assessing pulmonary hemodynamics, ventilation, and peripheral oxygen utilization were then compared within and across each cluster and with iCPET controls against peak oxygen consumption (Peak VO2). Results173 patients were enrolled. Sixty-seven patients underwent iCPET. All patients had reductions in Peak VO2 and peak cardiac index relative to controls. Three clusters were identified. Cluster one was defined by having elevated RV afterload and impaired ventilatory efficiency. Cluster two had elevated RV afterload with reductions in respiratory mechanics. Cluster three had mild derangement in RV afterload with mild reductions in peak cardiac output. InterpretationiCPET reveals significant heterogeneity in post PE dyspnea. Three phenotypes are characterized by differences in RV afterload, ventilatory efficiency, respiratory mechanics, and peripheral oxygen utilization.

Cardiac dysfunction in dialysing adults with end-stage kidney disease is associated with exercise intolerance: A pilot observational study.

People with end-stage kidney disease (ESKD) often exhibit impaired cardiac structure and function, which may contribute to poor exercise capacity. This study used multimodal exercise testing to investigate the central and peripheral mechanisms of exercise limitation in adults with ESKD, also comparing in-centre hemodialysis (ICHD) to home hemodialysis (HHD). Seventeen adults (55.5 ± 14.5 years; n = 14 male; n = 12 HHD) participated. Resting cardiac examinations, followed by submaximal cycling cardiopulmonary exercise testing (CPET) and functional exercise testing, revealed cardiac structural abnormalities (increased left ventricular mass) and cardiac injury. Aerobic fitness in adults with ESKD was low, with pulmonary oxygen uptake (V̇O2) at the gas exchange threshold (GET) occuring at 39 ± 8% predicted V̇O2peak. O2 pulse, an estimate of stroke volume (SV), was higher in HHD at rest (p = 0.05, ES = 0.58) and during unloaded cycling (p = 0.05, ES = 0.58) compared to ICHD. However, thoracic bioreactance derived SV at the GET was significantly higher in adults receiving ICHD versus HHD (p = 0.01, ES = 0.74). In adults with ESKD, cardiac output was positively associated with V̇O2 at the GET (r = 0.61, p = 0.04). This study highlights prevalent exercise dysfunction in adults with ESKD undergoing dialysis, with potential distinct differences between in-centre and home hemodialysis, mechanistically linked to underlying cardiac abnormalities.

Sigmoidal heart rate response pattern during exercise in patients with chronic heart failure.

Detailed heart rate (HR) response patterns during exercise in patients with heart failure (HF) and sinus rhythm remain uncertain. We screened consecutive patients with HF who underwent cardiopulmonary exercise tests at a large academic center from November 2013 to July 2023. HR response during exercise was statistically classified using logistic differential equation models. A total of 99 patients were included. Of them, 75 patients were assigned to "sigmoidal pattern" and the other 24 to "exponential pattern." Patients with the sigmoidal pattern were older and exhibited higher plasma B-type natriuretic peptide levels. Increases in HR and oxygen consumption (V̇o2)/kg up to the anaerobic threshold level were not different between both patterns. However, beyond the threshold, the sigmoidal pattern group showed no further increase in HR and significantly lower V̇o2/kg than their counterparts (interactions for P < 0.001). HR response during exercise in patients with heart failure and sinus rhythm was categorized into two unique groups: sigmoidal and exponential patterns. More detailed clarification of the sigmoidal pattern, potentially indicating sinus node dysfunction, should offer new clinical insights for chronotropic incompetence.NEW & NOTEWORTHY Heart rate response patterns can be classified into two groups among patients with chronic heart failure reaching maximal exertion: sigmoidal and exponential.

Pilot Study-Estimated VO2max via Modified Harvard Step Test (MHST) in Anterior Cruciate Ligament Injury Patients Undergoing Pre-Op Rehabilitation

Introduction: Anterior Cruciate Ligament (ACL) injury ranging from partial to full thickness tear causes much dysfunction physically and psychologically. It affects both daily &amp; sporting activities with potential of creating long term complications such as post-traumatic osteoarthritis of knee, functional limitations, increase in body mass index (BMI) and loss of cardiorespiratory fitness. Cardiorespiratory fitness is an important indicator for functional and fitness capacity and VO2max is used to measure cardiorespiratory fitness. VO2max is the maximum rate of oxygen consumption during a vigorous exercise. Cardiopulmonary exercise testing is usually done on a treadmill with gaseous exchange system, a process that is time consuming, expensive and difficult to assess and not available in our public health setting. Modified Harvard step test is easy to do, cost friendly and allows mass testing to measure cardiorespiratory fitness (VO2max) however there are inadequate data on ACL injury and its influence on cardiorespiratory fitness using modified Harvard step test. Method: A prospective study was done using patients attending Sports Medicine Gym Hospital Tuanku Ja’afar 2023 and data from 20 patients who were undergoing pre-ACL reconstruction rehabilitation were evaluated. Patients were divided into two groups according to post trauma duration; (&lt;6 months of injury and rehabilitation and &gt;6 months injury and rehabilitation). Patients were required to do modified Harvard step test and translated into VO2max scores. Anthropometric data were also taken from patients. Results: The mean age for our study is 21.9±4.3 years. The mean VO2max for the entire participant was 43.2ml/kg/min. Mean VO2max for groups &lt;6 months injury rehabilitation and &gt;6 months injury rehabilitation was at 35.4±1.8 ml/kg/min and 49.0± 5.8ml/kg/min respectively. We report difference in both groups VO2max Conclusion: Cardiorespiratory fitness is often reduced during earlier phase of injury due to inability to perform aerobic exercises. Progressive rehabilitation can improve cardiorespiratory fitness, aid in patients return to sports and reduces morbidity post operatively. Modified Harvard step test is a reliable and cost-effective method to test VO2max. It is also important to increase cardiorespiratory fitness to maintain healthy BMI.

The prognostic role of cardiopulmonary exercise testing in obesity.

Poor cardiorespiratory fitness has been suggested to increase the risk of chronic diseases in obesity. We investigated the ability of key variables from cardiopulmonary exercise testing (CPET) to predict all-cause mortality in an obese cohort. The sample included 469 participants of both sexes (mean age 40 ± 13 years) who underwent a CPET for clinical reasons between 1 March 2009 and 1 December 2023. All-cause mortality was the prognostic endpoint. A receiver operating characteristic analysis was performed to establish optimal cut-points for CPET variables. Kaplan-Meier and Cox regression analyses were used to determine the association between CPET variables and all-cause mortality. There were 46 deaths during a mean follow-up period of 69 ± 48 months, resulting in an annual mortality rate of 2%. Despite the sample being made up of mostly women (70%), there were more deaths in men (18 vs. 6%, p < 0.001).The optimal thresholds for discrimination of survival were as follows: (a) peak oxygen uptake (pVO2) ≤16 mL/kg/min; (b) minute ventilation/carbon dioxide production (VE/VCO2) slope ≥31; (c) ventilatory power ≤5.8 mmHg; and (d) circulatory power ≤2980 mmHg/mL O2/min. Kaplan-Meier survival plots revealed a significant positive association between lower pVO2, circulatory power and ventilatory power values and survival (log-rank, p < 0.001) and higher mortality for men than women. Adjusted Cox regression models showed that a pVO2 ≤16 mL/kg/min had a 20-fold higher risk of mortality when compared with >16 mL/kg/min. Given the strong association of VO2, ventilatory efficiency, circulatory and ventilatory power with all-cause mortality, our findings support the notion that poorer cardiorespiratory fitness is associated with a poor prognosis in patients with obesity.

Right-ventricle heart failure in PAH vs. HFrEF with secondary PH: Hemodynamic, ergospirometric, and organ function correlations

PurposeThe goal of the study was to identify markers of organ function used in daily routines that could potentially aid in the overall evaluation of the cardiovascular system in patients with right-ventricle heart failure due to pulmonary arterial hypertension (PAH) and left-ventricle heart failure. We analyzed correlations between parameters from right heart catheterization (RHC), cardiopulmonary exercise test (CPET), and selected laboratory parameters of thyroid, liver, kidneys function and iron homeostasis. Patients and methodsA retrospective analysis included 107 patients (mean age 57.6 ​± ​16.2; 34.6 ​% women), comprising 57 patients with PAH (mean age 54.0 ​± ​18.2; 49.1 ​% women) and 50 patients with heart failure with reduced ejection fraction (HFrEF) ​< ​40 ​% (mean age 61.6 ​± ​12.7; 18 ​% women). All patients underwent CPET. Each patient in the PAH group had RHC performed. Fifteen patients from the HFrEF group underwent RHC, which confirmed the suspicion of pulmonary hypertension (HFrEF-SPH). ResultsCPET and laboratory parameters’ analysis showed strong correlations between ventilation/carbon dioxide production (VE/VCO2) slope and NT-proBNP in HFrEF without secondary PH and HFrEF-SPH groups. In the PAH group, VE/VCO2 slope correlated with liver and thyroid function but also with morphological parameters of red-cell system.Analysis of correlations between laboratory and hemodynamic parameters revealed significant correlations between pulmonary arterial pressure, pulmonary vascular resistance (PVR) and red-cell parameters, especially strong with fT4 in the PAH group. ConclusionsIn HFrEF-SPH patients, laboratory parameters strongly correlated with pulmonary pressures and pulmonary capillary wedge pressure (PCWP).

Higher striatal dopamine is related with lower physical performance fatigability in community-dwelling older adults.

Fatigability in community-dwelling older adults is highly prevalent and disabling, but lacks a treatment. Greater nigrostriatal dopaminergic signaling can ameliorate performance fatigability in healthy young adults, but its role in community-dwelling older adults is not known. We hypothesized that higher nigrostriatal dopaminergic integrity would be associated with lower performance fatigability, independent of cardiopulmonary and musculoskeletal energetics and other health conditions. In 125 older adults participating in the Study of Muscle, Mobility and Aging, performance fatigability was measured as performance deterioration during a fast 400 meter walk (% slowing down from the 2nd to the 9th lap). Nigrostriatal DA integrity was measured using (+)-[11C] dihydrotetrabenazine (DTBZ) PET imaging. The binding signal was obtained separately for the subregions regulating sensorimotor (posterior putamen), reward (ventral striatum) and executive control processes (dorsal striatum). Multivariable linear regression models of performance fatigability (dependent variable) estimated the coefficients of dopamine integrity in striatal subregions, adjusted for demographics, comorbidities, and cognition. Models were further adjusted for skeletal muscle energetics (via biopsy) and cardiopulmonary fitness (via cardiopulmonary exercise testing). Higher [11C]-DTBZ binding in the posterior putamen was significantly associated with lower performance fatigability (demographic-adjusted standardized Beta = -1.08, 95% CI: -1.96, -0.20); results remained independent of adjustment for other covariates, including cardiopulmonary and musculoskeletal energetics. Associations with other striatal subregions were not significant. Dopaminergic integrity in the sensorimotor striatum may influence performance fatigability in older adults without clinically overt diseases, independent of other aging systems.

Modelling the long-term health impact of COVID-19 using Graphical Chain Models

BackgroundLong-term sequelae of SARS-CoV-2 infection, namely long COVID syndrome, affect about 10% of severe COVID-19 survivors. This condition includes several physical symptoms and objective measures of organ dysfunction resulting from a complex interaction between individual predisposing factors and the acute manifestation of disease. We aimed at describing the complexity of the relationship between long COVID symptoms and their predictors in a population of survivors of hospitalization for severe COVID-19-related pneumonia using a Graphical Chain Model (GCM).Methods96 patients with severe COVID-19 hospitalized in a non-intensive ward at the “Santa Maria” University Hospital, Terni, Italy, were followed up at 3–6 months. Data regarding present and previous clinical status, drug treatment, findings recorded during the in-hospital phase, presence of symptoms and signs of organ damage at follow-up were collected. Static and dynamic cardiac and respiratory parameters were evaluated by resting pulmonary function test, echocardiography, high-resolution chest tomography (HRCT) and cardiopulmonary exercise testing (CPET).ResultsTwelve clinically most relevant factors were identified and partitioned into four ordered blocks in the GCM: block 1 - gender, smoking, age and body mass index (BMI); block 2 - admission to the intensive care unit (ICU) and length of follow-up in days; block 3 - peak oxygen consumption (VO2), forced expiratory volume at first second (FEV1), D-dimer levels, depression score and presence of fatigue; block 4 - HRCT pathological findings. Higher BMI and smoking had a significant impact on the probability of a patient’s admission to ICU. VO2 showed dependency on length of follow-up. FEV1 was related to the self-assessed indicator of fatigue, and, in turn, fatigue was significantly associated with the depression score. Notably, neither fatigue nor depression depended on variables in block 2, including length of follow-up.ConclusionsThe biological plausibility of the relationships between variables demonstrated by the GCM validates the efficacy of this approach as a valuable statistical tool for elucidating structural features, such as conditional dependencies and associations. This promising method holds potential for exploring the long-term health repercussions of COVID-19 by identifying predictive factors and establishing suitable therapeutic strategies.