Vignati, Carlo; Centro Cardiologico Monzino, Milan, Italy.
Agostoni, Piergiuseppe;Pezzuto, Beatrice

Journal of cardiovascular development and disease [J Cardiovasc Dev Dis] 2026 Oct 20; Vol. 13 (10).
Date of Electronic Publication: 2026 Oct 20.

Major surgery imposes physiological stress requiring coordinated adaptation of the cardiovascular, respiratory, hematological, and musculoskeletal systems. Conventional preoperative assessment remains essential but may underestimate heterogeneity in physiological reserve because resting measurements incompletely capture the response to increasing metabolic demand. Cardiopulmonary exercise testing (CPET) provides an integrated assessment of oxygen transport and utilization, linking pulmonary ventilation and gas exchange to cardiovascular performance and peripheral oxygen extraction. This narrative review examines the role of CPET in preoperative assessment, from prognostic testing to physiological phenotyping and personalized perioperative care. We summarize the physiological basis of key variables, including peak oxygen uptake, anaerobic threshold, oxygen pulse, ventilatory efficiency, end-tidal carbon dioxide, breathing reserve, and exercise kinetics, and discuss how integrated interpretation can identify patterns suggestive of haemodynamic, ventilatory, pulmonary vascular, or peripheral limitations. Evidence across major surgical populations is critically appraised, with attention to isolated thresholds and the distinction between prognostic association and clinical effectiveness. The current data support selective rather than universal use of CPET, particularly when functional capacity is uncertain or physiological information may alter management. We propose a phenotype-oriented framework in which CPET findings identify potentially modifiable impairments and inform cardiovascular optimization, respiratory treatment, nutritional support, exercise training, and prehabilitation. Emerging approaches combining complex CPET, non-invasive haemodynamic assessment, wearable technologies, and artificial intelligence may enable personalized profiling, although prospective validation remains necessary. CPET should therefore be considered not simply a risk-prediction tool, but an in vivo interrogation of physiological reserve that can contribute to mechanism-oriented perioperative assessment.

Schön, Patrick; Department of Health Sciences and Technology, Zurich, Switzerland.
Boyle, Kyle G P J M; Beltrami, Fernando G;

International journal of cardiology. Congenital heart disease,2026 Aug 27

• Introduction: A decreased peripheral oxygen saturation (SpO₂ ) is common in Fontan patients. We aimed to determine whether these patients experience greater nocturnal desaturation (ΔSpO_2,noct ), and to which extent this may impact sleep quality and exercise performance, compared to healthy controls.
• Methods: 16 adult Fontan patients and 16 healthy, individually matched controls completed questionnaires on quality of life, sleep quality, and daytime sleepiness, performed measurements of lung function and diffusion capacity (DLCO), and cycled in a cardiopulmonary exercise test to volitional exhaustion. Sleep quality was assessed with a wrist-worn actigraph and nocturnal SpO₂ was measured with a pulse oximeter during six nights.
• Results: Fontan patients experienced greater ΔSpO_2,noct (-3.4 ± 0.8%-points, n = 14) compared to their controls (-2.5 ± 0.6%-points, n = 14, p = 0.001). In patients, ΔSpO_2,noct correlated with baseline SpO₂, DLCO, and exercise performance. Fontan patients had a longer sleep onset latency (22.8 ± 9.6 vs. 10.8 ± 6.0 min, p < 0.001) and lower self-perceived physical functioning (91 ± 7 vs. 100 ± 0 points, p < 0.001), but similar subjective sleep quality (4.2 ± 1.5 vs. 3.4 ± 1.4 points, p = 0.121) and daytime sleepiness (6.1 ± 4.3 vs. 6.3 ± 2.8 points, p = 0.884) compared to controls. In patients, daytime sleepiness correlated with the total number of desaturation events (r = 0.74, p = 0.003).
• Conclusion: Indices of nocturnal SpO₂ were related to daytime sleepiness and reduced exercise performance, and may therefore be a contributing factor to exercise limitation in adult Fontan patients. Enhancing nocturnal SpO₂ may thus be a promising target to improve daytime sleepiness and exercise performance in adult Fontan patients.

Howden, Erin J; Baker Heart and Diabetes Institute, Melbourne, Australia.;
Sesa-Ashton, Gianni;Foulkes, Stephen J; et al

American journal of physiology. Heart and circulatory physiology,2026 Oct 12

Purpose. Post-acute sequelae of COVID-19 syndrome (PASC) is widely attributed to dysautonomia, although sympathetic outflow has rarely been measured directly. We tested whether exercise and orthostatic intolerance in PASC reflect impaired cardiac reserve or abnormal muscle sympathetic nerve activity (MSNA) and its reflex control.
Methods. Adults with PASC (n=35; symptoms >3 months, no significant comorbidity) and age- and sex-matched recovered controls (n=12) underwent cardiopulmonary exercising testing (CPET), echocardiogram, resting and exercise cardiac MRI and peroneal microneurography recordings of MSNA in supine and during graded head up tilt to 60º.
Results. PASC participants had lower peak VO₂ indexed to lean mass (43.0±7.8 vs 52.2± 8.2ml/lean body mass kg/min, p=0.009) and whole-body mass (26.1± 7.5 v 34.9± 10.2ml/kg/min, p=0.006), lower heart rate reserve (84 ± 25 vs 98 ± 13 beats/min, p=0.019) and impaired ventilatory efficiency. Cardiac structure and biventricular contractile reserve were normal. Supine MSNA burst frequency, burst incidence, sympathetic baroreflex gain and neurovascular transduction did not differ between groups, and MSNA and mean arterial pressure increased similarly during tilt (time P <0.0001; group x time P =0.78). Despite this, 12 of 29 PASC participants (41%) terminated the tilt protocol due to orthostatic symptoms or pre-syncope (Kaplan-Meier P =0.0178). Eight participants (27%) met POTS criteria and had lower MSNA than non-POTS participants (P =0.045).
Conclusion. Orthostatic intolerance occurred despite normal recruitment of MSNA and maintained arterial pressure, and exercise intolerance despite preserved contractile reserve. Symptoms are therefore unlikely to originate in the efferent sympathetic limb or myocardium, and more likely reflect afferent reflex dysregulation or impaired cerebral perfusion.

Nunes Silva, Rebeca; Cardiopulmonary Physiotherapy Laboratory, Brazil
Crisci, Giulia; Losito, Maurizio; et al

European journal of preventive cardiology [Eur J Prev Cardiol] 2026 Oct 29.
Date of Electronic Publication: 2026 Oct 29.

• Aims: To characterize the pattern of chronotropic incompetence (CI) response to exercise in patients with heart failure (HF) across distinct phenotypes of the left ventricular ejection fraction and to explore the extent to which heart rate (HR) response should be prioritized as a therapeutic target within personalized HF management strategies.
• Methods: Patients with HF with preserved ejection fraction (HFpEF), HF with reduced ejection fraction (HFrEF), and healthy controls underwent incremental exercise testing with simultaneous gas exchange and echocardiography assessments. Stroke volume (SV), HR, cardiac output (CO), and arteriovenous oxygen difference [C(a-v)O2] were assessed from rest to peak exercise. Graphical analyses explored relationships amongst determinants of oxygen uptake (V̇O2).
• Results: Both HF phenotypes exhibited CI and a blunted increase in CO during exercise compared with controls. Peak HR was similarly reduced by 20% in HFpEF and 23% in HFrEF. HFpEF, however, exhibited a steeper HR-VO2 relationship. HFrEF demonstrated a greater compensatory increase in peripheral O2 extraction, with peak C(a-v)O2 73% higher than controls and 21% higher than HFpEF. In contrast, HFpEF showed limited ability to augment C(a-v)O2 and presented the lowest relative peak V̇O2 (-39% vs. controls and -16% vs. HFrEF), despite similar peak V̇O2%pred between HF phenotypes.
• Conclusion: CI can contribute to exercise intolerance in both HF phenotypes, with distinct compensatory mechanisms. An integrated cardiopulmonary exercise testing-echocardiography approach may support identifying phenotype-specific physiological profiles that might address therapeutic strategies targeting CI, SV reserve, and peripheral O2 utilization to improve functional capacity in HF. Addressing the kinetics of HR slope and ΔHR metrics seems relevant to implement knowledge on the fundamental CI contribution in HF phenotypes.

Marinho, Maria de Fátima Duarte; University of Sao Carlos (UFSCar), SP, Brazil.
Schafauser-Segundo, Nathany Souza; Hurst, John R;

Respiratory medicine [Respir Med] 2026 Oct 29; Vol. 264, pp. 109251.
Date of Electronic Publication: 2026 Oct 29.

• Background: Chronic respiratory diseases (CRD) are accompanied by coexisting chronic conditions, which may occur individually or as multimorbidity burden or patterns. These conditions may contribute to exercise intolerance, a determinant of prognosis. However, their association with exercise capacity remains unclear. This study aimed to evaluate, in individuals with CRD, the association between one or more other chronic conditions (multimorbidity) and exercise capacity and to quantify this relationship through meta-analysis.
• Methods: Searches were conducted in PubMed, Scopus, Embase, Web of Science, Virtual Health Library, and CINAHL until July 2025. Observational studies evaluating exercise capacity in adults with CRD, with coexisting chronic conditions, using field- or laboratory-based tests were included. Methodological quality was assessed using Joanna Briggs Institute checklists. Meta-analyses were performed using random-effects models.
• Results: A total of 49 studies were included in the qualitative synthesis (n = 28,972 participants), and 23 contributed to the quantitative synthesis. Most studies involved individuals with chronic obstructive pulmonary disease. Sensitivity analyses excluding outliers yielded clinically meaningful reductions in 6-min walk distance for metabolic (MD -34.26 m; 95% CI -46.98 to -21.53; I²  = 5.91%), cardiovascular (MD -27.18 m; 95% CI -39.59 to -14.78; I²  = 16.19%), and mental health conditions (MD -29.52 m; 95% CI -54.89 to -4.15; I²  = 0%).
• Conclusions: In individuals with CRD, multimorbidity is associated with reduced exercise capacity, with clinically meaningful reductions particularly in the presence of metabolic and cardiovascular conditions. Although the certainty of evidence is very low, these findings highlight the importance of considering multimorbidity when interpreting exercise limitation in CRD.

Federico, Robert J;  Department of Health and Physical Education, Monmouth University, West Long Branch,USA.
Caba-Abreu, Tiffany A; Pigman, Jamie et al

Journal of functional morphology and kinesiology,2026 Sep 25

Background and Objectives: Warm-up before cardiopulmonary exercise testing (CPET) typically includes low-intensity aerobic activity. Whether a dynamic suspension-training warm-up represents a comparable alternative remains unknown. This study compared the cardiopulmonary responses between a treadmill walking warm-up (WW) and a suspension training warm-up (SW) before CPET in highly active young adults.
Methods: Fifteen participants (6 females, 9 males; 21.2 ± 1.90 years) randomly completed both 6 min warm-up conditions in a randomized, counterbalanced order before an incremental treadmill CPET using a portable metabolic analyzer. Equivalence of peak oxygen uptake (VO₂ peak) was assessed using two one-sided tests with a prespecified bound of ±1 MET (±3.5 mL/kg/min).
Results: VO₂ peak between SW (58.8 mL/kg/min; SD = 9.33) and WW (58.9 mL/kg/min; SD = 10.34) did not differ significantly (p = 0.957, d = -0.01). The 90% CI for the differences (-2.48 to 2.33 mL/kg/min) fell within the equivalence bounds (p = 0.010 and p = 0.013). Linear mixed model analyses revealed no significant effect of warm-up on VO₂ peak (F_1,13 = 0.003, p = 0.957) with no sequence-order effects (p > 0.05). Other peak CPET cardiopulmonary, perceptual, and performance outcomes did not differ between warm-ups (p > 0.05).
Conclusions: A SW elicited equivalent VO₂ peak and no significant differences in other CPET outcomes compared to a traditional WW in highly active young adults. These findings provide novel evidence that SW may represent a practical alternative warm-up before CPET in highly active young adults.

Huang, Yu-Ting; College of Medicine, National Cheng Kung University, Tainan City Taiwan.
Cheng, Hui-Ching; Yang, Hsin-Lun;

Contemporary clinical trials,2026 Oct 22

• Introduction: Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation, which reduces exercise capacity. Although current guidelines recommend moderate-to-vigorous aerobic exercise to achieve optimal physiological adaptations, many patients cannot sustain the required intensity, limiting overall therapeutic benefit. This study protocol aims to evaluate the effects of combining blood flow restriction (BFR) with aerobic training on exercise capacity, cardiopulmonary function, and health-related quality of life in patients with COPD, compared with conventional aerobic training or usual care.
• Methods: We will conduct a single-center, prospective, parallel-group randomized controlled trial. 45 clinically stable patients with COPD (GOLD stages II-IV) will be recruited. Eligible participants must have had no acute exacerbations in the past two months and be able to participate in the exercise training program. Participants will be randomly assigned to one of three groups: usual care, conventional aerobic training (60-80% VO₂ peak), or BFR-enhanced aerobic training (40-50% VO₂ peak, with 40-80% arterial occlusion pressure). All exercise sessions will be supervised, three times per week for eight weeks. The primary outcome is exercise capacity. Secondary outcomes include pulmonary function tests, respiratory muscle strength, diaphragmatic ultrasound, heart rate variability, and health-related quality-of-life questionnaires.
• Planned Outcomes: BFR-enhanced aerobic training may be a safe and effective rehabilitation option for COPD patients who cannot tolerate high-intensity exercise. The BREATH trial is expected to provide essential evidence for clinical care by integrating BFR training into pulmonary rehabilitation. This approach could inform future management strategies for exercise intolerance among patients with COPD.