Sakellaropoulos, Stefanos G; Department of Cardiology, University Hospital and University of Basel, Basel, Switzerland.;
Mohammed, Muhemin;Sakellaropoulos, Panagiotis;Ali, Muhammad;+6 more

Cardiology research,2025 Dec 20

Other than the traditional risk factors for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) – detected by means of anamnesis, Holter monitoring, exercise testing, echocardiography and cardiac magnetic resonance imaging – exercise oscillatory ventilation (EOV), detected by cardiopulmonary exercise testing (CPET), has recently been observed in patients with HCM. EOV is considered as one of the most important independent risk factors for morbidity, mortality and SCD in patients with reduced, as well as with preserved ejection fraction. Considering HCM as a prototype of heart failure with preserved ejection fraction, we would like to present a short, specific review concerning EOV as a potential new risk factor for SCD in HCM.

Sugita, Yousuke; Faculty of Health Sciences, Tsukuba University of Technology, Ibaraki, Japan.
Kudo, Ayano;Arakawa, Sota;Sakai, Satoshi

Heart and vessels,2025 Dec 29

Background Reduced exercise capacity is a hallmark of heart failure with preserved ejection fraction (HFpEF), and this limitation is particularly pronounced in older patients with coexisting type 2 diabetes mellitus (T2DM), a high-risk population characterized by poor prognosis. Although previous studies have demonstrated that exercise training (ET) can improve exercise capacity in patients with HFpEF, its efficacy in older patients with coexisting HFpEF and T2DM remains unclear.
Methods Therefore, we evaluated the effects of ET on peak oxygen uptake (peakVO ₂ ) and 6-min walk distance (6MWD) in older patients with HFpEF and investigated whether these effects differ based on T2DM status. A total of 99 stable outpatients with HFpEF aged 65 to 80 years were enrolled. Participants were classified into four groups based on T2DM and ET status: T2DM-ET (n = 25), non-T2DM-ET (n = 24), T2DM-usual-care (UC; n = 26), and non-T2DM-UC (n = 24). PeakVO ₂ and hemodynamic responses during exercise were assessed using cardiopulmonary exercise testing and impedance cardiography. Additionally, walking distance, cadence, step length, and metabolic cost were assessed during the 6-min walk test. The interaction between T2DM and ET on changes in these parameters was analyzed using multivariable-adjusted linear regression.
Results ET significantly improved peakVO ₂ after 5 months; however, the magnitude of improvement was attenuated in the T2DM group (0.5 mL/kg/min) compared with that in the non-T2DM group (1.9 mL/kg/min; p < 0.001). This difference was primarily attributable to a blunted increase in arteriovenous oxygen difference, which increased by only 0.2 mL/100 mL in the T2DM group vs. 0.4 mL/100 mL in the non-T2DM group (p < 0.001). In contrast, improvements in 6MWD were similar between the groups (29 vs. 31 m; p = 0.651). Step length remained unchanged, whereas cadence increased in the T2DM and non-T2DM groups (11 vs. 8 steps/min, respectively), accompanied by a reduction in metabolic cost (- 0.06 vs. – 0.04 mL/kg/m), indicating enhanced walking efficiency regardless of T2DM status. Although T2DM attenuated improvements in peakVO ₂ , the walking efficiency and functional capacity improved with ET regardless of T2DM status.
Conclusions These findings highlight the potential value of ET in older patients with HFpEF, irrespective of T2DM status.

Duregon, Federica; Sports and Exercise Medicine Division, Department of Medicine, University of Padova, Padova, Italy.
Quinto, Giulia;Vecchiato, Marco;Faggian, Sara;+7 more

BMC sports science, medicine & rehabilitation,2025 Dec 29

• Background: Although physical exercise is an evidence-based treatment for patients with chronic diseases, providing benefits in terms of morbidity, mortality and quality of life, its implementation in real-world healthcare systems is still limited. Even when physicians recommend physical activity, compliance and adherence to exercise programs remain very low. This study aims to implement a real-world model for tailored exercise prescription (TEP) in an outpatient clinic to evaluate feasibility, effectiveness, compliance and adherence.
• Methods: A TEP was set for each participant, based on a complete clinical and functional evaluation including cardiopulmonary exercise testing and fitness test battery. Subsequent supervised training sessions (STS) were performed for at least 6 weeks. After 6 months functional evaluations were repeated, also assessing compliance with general recommendations and adherence to the prescribed exercise program.
• Results: A total of 312 patients (44% male) with a mean age of 52.1 ± 13.6 years were enrolled. The most frequent main chronic conditions were obesity (47%), solid organ transplantation (32%), primary cardiovascular diseases (8%) and cancer (4%). The initial STS program was completed by 85.9% of patients, all without adverse events. Patient compliance, measured as attendance at the follow-up meeting, was 53.2%, while adherence to the TEP during the 6-month program was 44.9%.
• Conclusion: A real-word model for TEP followed by a period of STS is feasible in patients with chronic diseases in a real outpatient clinical setting. However, intervention strategies based on behavioral change and motivation are needed to foster greater compliance and adherence in the mid-to-long term.

Foulkes, Stephen J; Exercise and Research Trials (HEART) Lab, St Vincent’s Institute of Medical Research, Fitzroy, Australia.
Moura-Ferreira, Sara;Milani, Mauricio;Bekhuis, Youri;+13 more

Journal of cardiac failure,2025 Dec 30

• Objective: Atrial fibrillation (AF) is a common comorbidity in patients with heart failure with preserved ejection fraction (HFpEF) that contributes to increased morbidity and mortality. We sought to evaluate the impact of AF on key HFpEF features, including exercise tolerance (peak oxygen uptake, VO ₂ peak) hemodynamic responses, and peripheral oxygen extraction (a-vO ₂ diff).
• Methods: Patients referred to a multi-disciplinary unexplained dyspnea clinic and diagnosed with HFpEF following comprehensive clinical and hemodynamic evaluation were stratified on whether they were in persistent/permanent AF (AF _Persist ; n=86), paroxysmal AF (AF _Parox ; n=328) or sinus rhythm (SR; n=274). Cardiopulmonary exercise testing with simultaneous echocardiography (CPETecho) was applied to assess the VO ₂ peak, a-vO ₂ diff and exercise hemodynamics. Groups were compared using ANCOVA with adjustment for age, sex, body mass index, and the presence of hypertension and diabetes.
• Results: Compared to patients in SR or with AF _Parox , HFpEF patients with AF _Persist had a lower VO ₂ peak (1.3-2.4mL/kg/min lower, P<0.001). This coincided with lower peak exercise cardiac output (CO, 0.6-1.2L/min lower), secondary to a lesser stroke volume (14-17mL lower, P<0.001) and a smaller left-ventricular end-diastolic volume (15-18mL lower, P<0.001) that tended to decrease during exercise. In contrast, there was no impact of AF status on peak exercise a-vO ₂ diff, mean pulmonary artery pressure (mPAP) or the mPAP/CO slope.
• Conclusion: Patients with HFpEF and AF _Persist have a lower VO ₂ peak secondary to decreased CO, SV and reduced end-diastolic volume reserve. Rhythm control strategies may therefore be pivotal in optimizing exercise performance and clinical outcomes in patients with HFpEF and AF.

Billany, Roseanne E; Division of Cardiovascular Sciences, University of Leicester, Leicester, UK.;
Vadaszy, Noemi;Burns, Stephanie;Chowdhury, Rafhi;+11 more

Clinical rehabilitation,2025 Dec 30

Objectives(1) Explore the effects of a 12-week home-based rehabilitation programme on cardiorespiratory fitness in kidney transplant recipients; (2) Compare cardiorespiratory fitness parameters in kidney transplant recipients and age-sex matched healthy volunteers to aid the justification for routine rehabilitation programmes.
Design Pilot randomised controlled trial with nested case-control.
Setting Home-based rehabilitation; hospital-based outcome assessments.
Participants Pilot randomised controlled trial: 50 stable kidney transplant recipients (>1 year post-transplant) (randomised 1:1; n = 25 control and n = 25 intervention). Nested case-control: 30 kidney transplant recipients and 30 healthy volunteers.InterventionA 12-week home-based aerobic and resistance rehabilitation programme or guideline-directed care control.
Main measures Cardiorespiratory fitness measured by cardiopulmonary exercise testing.
Results Pilot randomised controlled trial: After adjusting for baseline, follow-up values were significantly greater in intervention compared to control for peak oxygen uptake (V̇O _2peak ) mL/kg/min, (+1.50, p = .03) and maximum workload (+8 W, p = .04) but not V̇O _2peak L/min or variables at the gas exchange threshold. Higher frequency of aerobic exercise sessions was associated with greater improvements in cardiorespiratory fitness ( R₂ = .252, p = .040).Nested case-control: V̇O _2peak was reduced in kidney transplant recipients compared to healthy volunteers (18.81 ± 4.61 vs 24.06 ± 5.72 mL/kg/min; p < .01), as was V̇O ₂ at the gas exchange threshold (11.70 ± 2.67 vs 14.47 ± 3.39 mL/kg/min; p < .01).
Conclusions A 12-week home-based rehabilitation programme induced a significant improvement in some cardiorespiratory fitness variables and higher frequency of aerobic exercise associated with greater improvements. Cardiorespiratory fitness is significantly impaired in kidney transplant recipients compared to age-sex-matched healthy volunteers. Together, these findings highlight the clinical importance of promoting aerobic exercise and the integration of rehabilitation programmes into routine care for this population.

Morimoto, Junko; Department of Cardiovascular Medicine, Arida City Hospital, Wakayama 6490316, Japan.
Taruya, Akira;Satogami, Keisuke;Taniguchi, Motoki;+10 more

International journal of cardiology,2025 Dec 30

• Background: Cardiopulmonary exercise testing combined with stress echocardiography (CPET-SE) allows the non-invasive assessment of cardiac function and oxygen metabolism during exercise. However, their prognostic value in older patients with heart failure (HF) remains unclear. This study aimed to determine whether left ventricular diastolic function at the anaerobic threshold (AT) predicts 1-year composite outcomes, defined as cardiovascular death or worsening HF, in older patients with HF.
• Methods: In this study, 104 older patients with HF who underwent CPET-SE were prospectively enrolled. Of the initial cohort, 15 patients (14 %) were excluded due to inability to obtain e’ measurements, and one patient for loss of follow-up. Ultimately, 88 patients were included in the analysis. Patients were divided into event and non-event groups based on 1-year outcomes. Diastolic function was evaluated by measuring e’ at rest and immediately after reaching the AT (e’ _AT ), and values were compared between groups.
• Results: No adverse events related to the CPET-SE were observed. Only 10.2 % of the patients reached the target heart rate. During the follow-up, 26 patients (29.6 %) experienced composite events. Multivariate analysis revealed that e’ _AT , along with the presence or absence of atrial fibrillation, remained as a prognostic factor of the composite outcomes. An e’ _AT cutoff <6.0 cm/s demonstrated 89 % sensitivity and 84 % specificity for predicting events.
• Conclusions: An e’ _AT value of <6.0 cm/s derived by CPET-SE is a feasible and robust prognostic marker in older patients with HF. CPET-SE may be an adjunct tool for risk stratification, complementing conventional biomarkers, echocardiography, and CPET parameters.

Páez, Valeria; Faculty of Health Sciences, Universidad de Antofagasta, Antofagasta, Chile.
Lozano, Sofia;Calfil, Danixza;Andrade, David Cristóbal;+1 more

Physiological reports,2026 Jan

High-altitude (HA) exposure induces cardiovascular, respiratory, and metabolic adjustments that often impair exercise performance. These physiological responses depend on hypoxic severity, exposure duration, and individual susceptibility. Although full acclimatization generally requires about 7 days, early adaptations can emerge within the first 72 h. This study aimed to characterize these early responses and to evaluate the potential of mathematical modeling to predict HA-related exercise performance decline. Nine healthy volunteers (age: 24.4 ± 3.3; weight: 63.7 ± 11.8; height: 169.4 ± 8.4; female: 44%) completed maximal cardiopulmonary exercise tests under three conditions: at sea level (SL), and at 3015 m after 12 h (HA12h) and 60 h (HA60h) of exposure. Although 60 h at HA was insufficient for full acclimatization, significant differences were observed between HA12h and HA60h, indicating partial physiological adaptation. Maximal power output declined at both HA time points. Notably, HA-induced performance deterioration was accurately predicted (R ² = 0.81) using SL-derived parameters, particularly maximal oxygen pulse (VO ₂ /HR _max ) and the ventilatory equivalent for carbon dioxide (VE/VCO ₂ ). These findings provide novel insights into early physiological responses to HA and support the development of individualized, model-based tools to anticipate performance loss and optimize training and acclimatization strategies.

Bjerregaard, Louise; Beth Israel Deaconess Medical Center and Harvard Medical School,  Boston,  USA;
Maron, Martin S;Jensen, Morten S K;Dybro, Anne M;+3 more

International journal of cardiology,2026 Jan 01

• Introduction: In obstructive hypertrophic cardiomyopathy (oHCM), peak oxygen consumption (pVO ₂ ) by cardiopulmonary exercise testing (CPET) and patient-reported outcomes with Kansas City Cardiomyopathy Questionnaire (KCCQ), are increasingly utilized to assess efficacy in clinical trials. However, in clinical practice, treatments have historically been based on physician assessment of symptoms with New York Heart Association (NYHA) classification. We aimed to evaluate relationship between NYHA classification, pVO ₂ and KCCQ in oHCM.
• Methods: Consecutive patients with oHCM undergoing CPET and KCCQ at two HCM-centers. Correlations were assessed between continuous measures and according to subgroups of pVO ₂ (<14, 14-20, >20 mL/kg/min), KCCQ-overall summary score (OSS) (≤50, 51-75, >75) and NYHA class (III/IV, II, I) to reflect moderate to severe, mild to moderate, and little to no limitations.
• Results: Clinical evaluation and CPET were performed in 75 patients: 59 ± 13 years, resting LVOT gradient 81 ± 29 mmHg, pVO ₂ 17.6 ± 4.5 mL/kg/min, with 88 % NYHA class ≥II and 83 % with KCCQ-OSS <75. NYHA classification was moderately associated with KCCQ-OSS (ρ = -0.596, p < 0.001) and borderline correlated with pVO ₂ (ρ = -0.223, p = 0.055). pVO ₂ showed a weak correlation with KCCQ-OSS (r = 0.361, p = 0.002). On patient level, a discordance in the severity of limitations between each test was present: 55 % between pVO ₂ and NYHA, 53 % between pVO ₂ and KCCQ-OSS and 40 % between KCCQ-OSS and NYHA class.
• Conclusion: Poor correlation and substantial differences were observed between physician assessed symptom burden, objective measures of exercise capacity, and patient-reported measures. These findings provide insight for considered in the context of clinical management decisions and clinical trials in oHCM.

Williams, Thomas G; Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada.
Collins, Sophie É;Brotto, Andrew R;D’Souza, Andrew W;+5 more

Chest,2026 Jan 02

• Background: The prevalence of e-cigarette use is increasing, and e-cigarette users with no history of tobacco smoking report greater respiratory symptoms. Traditional evaluation of resting pulmonary function may fail to detect subclinical abnormalities.
• Research Question: To what extent do young, otherwise healthy chronic e-cigarette users with no tobacco smoking history exhibit altered cardiopulmonary function during exercise, and altered recruitment of pulmonary diffusing capacity (DL _CO )?
• Study Design and Methods: 20 chronic e-cigarette users (mean age: 23±4 years) with no tobacco smoking history and 20 age-, height-, and sex-matched controls underwent a pulmonary function test and cardiopulmonary exercise test. Key outcomes included exercise capacity (V˙O _2peak ), ventilatory efficiency (V˙ _E /V˙CO ₂ nadir), exertional dyspnea, and operating lung volumes during exercise. A secondary aim investigated recruitment of resting DL _CO and its components, measured as the change from the seated to supine posture. Adjusted linear regression models were used to evaluate the effect of group on key outcome variables at rest and during exercise.
• Results: Both groups presented with normal pulmonary function (all p _group >0.05). E-cigarette users demonstrated a lower V˙O _2peak (p _group =0.017), elevated V˙ _E /V˙CO ₂ nadir (p _group =0.037), and greater exertional dyspnea (p _group <0.001, p _{group*workload} <0.001), while operating lung volumes did not differ from controls (all p>0.05). E-cigarette users also displayed a blunted DL _CO recruitment to a postural change (p _{group*posture} =0.036). Between-group differences in dyspnea and DL _CO recruitment were independent of V˙O _2peak .
• Interpretation: Young, otherwise healthy chronic e-cigarette users exhibit evidence of abnormal cardiopulmonary responses to exercise, and blunted DL _CO recruitment. These findings suggest early cardiopulmonary impairment and pulmonary vascular dysfunction in young e-cigarette users.

Rattley, Catherine A; Faculty of Health and Social Science, Bournemouth University, Bournemouth, UK.
Felton, Malika;Ansdell, Paul;Dewhurst, Susan;+1 more

Climacteric : the journal of the International Menopause Society,2025 Dec

BACKGROUND Maintaining fitness throughout menopause is crucial for sustaining functional capacity and supporting healthy aging. Declines in physical activity and changes in physiology threaten cardiovascular health in menopause. Aerobic capacity is an indicator of current health status that can be measured directly, by maximal rate of oxygen uptake (V̇O _{2 max} ), or using submaximal predictive methods that require fewer resources.
AIMS This study aimed to establish the validity of these predictive methods for midlife women.
METHODS Forty-four women (age 52 ± 4 years) completed three predictive cycle ergometer protocols (YMCA, Astrand-rhyming and Ekblom-Bak) and an incremental cycle ergometer V̇O _{2 max} test. Predicted V̇O _{2 max} scores were compared for agreement with directly measured V̇O _{2 max} .
RESULTS All methods evidenced moderate correlations with V̇O _{2 max} . The mean V̇O _{2 max} value derived from the YMCA (35.6 ± 9.7 ml·kg- ¹ ·min- ¹ ) and Astrand-Rhyming (35.5 ± 8.8 ml·kg- ¹ ·min- ¹ ) tests was no different to measured V̇O _{2 max} (34.5 ± 7.2 ml·kg- ¹ ·min- ¹ ), but the Ekblom-Bak test (37.5 ± 7.2 ml·kg- ¹ ·min- ¹ , p < 0.01) overpredicted V̇O _{2 max} .
CONCLUSIONS All methods showed wide limits of agreement, suggesting variability in the accuracy of predictions.
When measuring aerobic capacity or prescribing exercise using these predictive methods, the results should be interpreted with caution. Where possible, direct measurement of aerobic capacity should be utilized for prescription of exercise intensity in menopausal women.