Avgeridou S ; Department of Congenital and Pediatric Heart Surgery, Munich, Germany.
Matsubara M; Dumitru R; Schaeffer T et al

Cardiol Young. 2026 Jul;36(7):1479-1486.

OBJECTIVES: The impact of conotruncal anomalies on long-term outcomes after total cavopulmonary connection remains unclear, particularly regarding haemodynamic performance and dominant ventricular morphology.
METHODS: All patients who underwent total cavopulmonary connection between 1994 and 2023 at a single centre were reviewed. Conotruncal anomalies were defined as transposition of the great arteries, double outlet right ventricle, tetralogy of Fallot, truncus arteriosus, and interrupted aortic arch type B. Four endpoints were analysed: transplant-free survival, Fontan failure, tachyarrhythmia, and ventricular dysfunction. Multivariable Cox regression, inverse probability of treatment weighting, and subgroup analyses were performed to disentangle conotruncal anomaly effects from dominant ventricular morphology.
RESULTS: Among the 650 patients, 291 (44.8%) were identified with conotruncal anomalies. During a median follow-up of 6.3 years, no differences were observed in transplant-free survival (log-rank p = 0.136) or Fontan failure (p = 0.717) between groups. Dominant right ventricular morphology was independently associated with Fontan failure (hazard ratio: 2.20; p = 0.006) and tachyarrhythmia (hazard ratio: 3.22; p = 0.004). These findings were confirmed across all sensitivity analyses. No differences were detected in filling pressures, cardiac index, or peak oxygen uptake on post-operative catheterisation (n = 226) and cardiopulmonary exercise testing (n = 161). When stratified into four groups by conotruncal status and dominant ventricular morphology, freedom from Fontan failure clustered by morphology rather than diagnostic category (4-way log-rank p < 0.001).
CONCLUSIONS: Conotruncal anomalies are not independently associated with adverse outcomes following total cavopulmonary connection. Dominant right ventricular morphology, not diagnostic category, is the principal determinant of long-term Fontan outcomes

Dziano, J.K.,Centre for Heart Rhythm Disorders, Royal Adelaide Hospital, Australia
Ariyaratnam, J.P., Howie, J.,et al

Heart Rhythm 2026 Issue 10 Pages e2456-e2465

BACKGROUND: Assessment of left ventricular (LV) function is an essential component of guideline-recommended management of atrial fibrillation (AF). However, the role and implications of right ventricular (RV) dysfunction in AF are poorly understood.
OBJECTIVE: This study aimed to determine the prevalence of RV dysfunction and evaluate its association with cardiorespiratory fitness (CRF) and symptom burden in patients with symptomatic AF.
METHODS: Consecutive adults with symptomatic paroxysmal or persistent AF and preserved LV ejection fraction scheduled for catheter ablation underwent transthoracic echocardiography, cardiopulmonary exercise testing, and AF symptom assessment. RV dysfunction was defined as tricuspid annular plane systolic excursion of </=1.7 cm and/or tissue Doppler s’ velocity of </=9.5 cm/s. CRF was determined by peak oxygen consumption (peak oxygen uptake [VO(2peak)]) during cardiopulmonary exercise testing.
RESULTS: Among 241 patients (mean age 66 +/- 10 years; 25% female), RV dysfunction was present in 35 patients (14.5%) despite preserved LV systolic function. Patients with RV dysfunction had lower CRF (VO(2peak) 17.9 +/- 6.7 vs 21.1 +/- 6.6 mL/kg/min; P = .01) independent of rhythm, with a greater proportion exhibiting severely reduced CRF (VO(2peak) <16 mL/kg/min: 43% vs 23%; P = .026). There was no association between RV dysfunction and AF symptom severity (P = .59). Structural chamber dimensions were comparable. Patients with RV dysfunction demonstrated higher E/e’ (P = .006), lower left atrial reservoir strain (P < .001), and LV global longitudinal strain (P < .001).
CONCLUSION: RV dysfunction is present in a substantial proportion of patients with symptomatic AF despite preserved LV systolic function and is independently associated with reduced CRF. Reduced RV function may be considered as a therapeutic target in the treatment of symptomatic AF.

Hogwood, A.C. Cardiovascular Research Center Virginia, United States.
Smarz, K., Golino, M., Tysarowski, M et al

Curr Probl Cardiol 2026 Issue 10 Pages 103382

BACKGROUND: Modern treatment of ST-elevation myocardial infarction (STEMI), emphasizing prompt reperfusion, has improved clinical outcomes by preserving cardiac function. Despite this, cardiorespiratory fitness remains impaired. The purpose of this study was to assess determinants of cardiorespiratory fitness in patients with reperfused STEMI and preserved cardiac function.
METHODS: We prospectively collected data from two patient cohorts with reperfused STEMI who underwent cardiopulmonary exercise testing on either a semi-supine cycle ergometer (Cohort 1) or treadmill (Cohort 2). Peak oxygen consumption (VO(2)) was measured as mL.kg(-1).min(-1) and as percent-predicted. Cardiac reserve was measured with Doppler echocardiography using heart rate (HR), stroke volume (SV), and cardiac output (CO) before and at peak exercise. Arterial-venous oxygen difference (a-v O(2)diff) was calculated using the Fick equation.
RESULTS: We included ninety-five patients (58 [51-65] years, 34% female) tested 41 [37-45] days after STEMI (Cohort 1: n = 39; Cohort 2: n = 56). Resting LVEF was 55 [50-59] %, with 2 (2%) having <40%. E’ velocity was 8.8 [7.3-10.5] and E/e’ was 7.6 [6.5-9.2]. Peak VO(2) was 20.0 [16.3-22.9] mL.kg(-1).min(-1), and 74 (78%) and 24 (25%) patients had reduced peak VO(2) at <80% and <60% of predicted, respectively. A significant positive correlation was observed between peak VO(2) and peak CO (R = 0.42, p = 0.0001), SV (R = 0.24, p = 0.02), HR (R = 0.36, p = 0.006), and a-v O(2)diff (R = 0.49, p < 0.0001). Peak HR and SV were each independent predictors of peak VO(2) using multivariate analyses (all p < 0.01).
CONCLUSION: Cardiorespiratory fitness remains impaired after successfully reperfused recent STEMI, despite rather preserved resting cardiac function. Cardiac and peripheral reserve partially explain the impairments, and preserving these may improve fitness after STEMI.

Liu, R., Beijing,  China.
Arena, R., Santos-de-Araujo, A.D., Borghi-Silva, A. & Popovic, D.

Curr Probl Cardiol 2026 Issue 10 Pages 103399

BACKGROUND: Atherosclerotic cardiovascular disease remains a leading cause of morbidity and mortality worldwide. Established risk equations guide prevention but rely mainly on static, clinic-based variables and incompletely capture physical activity, sedentary behavior, and cardiorespiratory fitness. METHODS: This narrative review synthesizes evidence from epidemiological studies, clinical trials, and methodological frameworks on the roles of physical activity, sedentary behavior, and cardiorespiratory fitness in cardiovascular risk prediction, with emphasis on digital phenotyping, mechanistic exercise physiology, and multimodal clinical prediction models.
RESULTS: Cardiorespiratory fitness reflects integrated physiological reserve and is strongly associated with cardiovascular and all-cause outcomes. Cardiopulmonary exercise testing extends fitness assessment by identifying mechanisms of exercise limitation, including cardiac, ventilatory, autonomic, pulmonary vascular, and peripheral contributors. Wearable technologies provide longitudinal, real-world measures of physical activity and sedentary behavior that complement static clinical risk factors. Multimodal models integrating electronic health records, electrocardiography, imaging, wearable signals, and exercise testing may support more personalized and actionable risk stratification. However, the current evidence base remains limited by insufficient external and prospective validation, incomplete calibration reporting, limited decision-analytic evaluation, and inadequate assessment of subgroup performance and equity.
CONCLUSIONS: Physical activity and cardiorespiratory fitness should be considered clinically relevant and modifiable phenotypes in contemporary cardiovascular risk prediction. Future models should prioritize standardized measurement, mechanistic validation of digital phenotypes, calibration, external validation, subgroup evaluation, workflow feasibility, and prospective evidence of clinical utility before widespread implementation.

Schwendinger, F., University of Basel, Basel.
Wagner, J., Hauser, C., Fleischlin, E.,

J Hypertens 2026 Issue 10 Pages 1881-1889

INTRODUCTION: Arterial hypertension (AH) impairs vascular function which, in turn, may reduce cardiopulmonary function. However, the impact of AH on cardiorespiratory fitness (CRF) and its potential mechanisms remains insufficiently investigated. We compared cardiopulmonary function during exercise testing (CPET) between adults with and without AH (part 1) and evaluated the effects of high-intensity interval training (HIIT) in adults with AH on submaximal cardiopulmonary CPET parameters (part 2).
METHODS: Thirty-eight adults with AH and 19 controls without AH partook in the study. Adults with AH were randomized into either HIIT or a control group. CPET assessed CRF and submaximal exercise parameters, including the oxygen uptake efficiency slope (OUES), V̇E/V̇CO 2 slope, PETCO 2 , V̇O 2 /work rate (WR) slope, and O 2 pulse. The HIIT intervention consisted of triweekly sessions over 8 weeks.
RESULTS: Adults with AH had a 6.5 ml kg -1 min -1 (95% confidence interval: 1.7-11.3) lower CRF, a steeper V̇E/V̇CO 2 slope (moderate-large effect size), lower PETCO 2 (large effect size), flatter V̇O 2 /WR slope (moderate effect size), and lower O 2 pulse (small-moderate effect size) than adults without AH. HIIT improved CRF and altered certain cardio-circulatory parameters in AH, including OUES (small-large effect size), V̇O 2 /WR slope (small-moderate effect size, low precision) and O 2 pulse (small-moderate effect size). However, effects of HIIT on pulmonary-vascular parameters were inconclusive, with large variability observed in the V̇E/V̇CO 2 slope and PETCO 2 .
CONCLUSION: Adults with controlled AH might have lower CRF, indicating limitations in pulmonary-vascular and cardio-circulatory organ systems. A short-term 8-week HIIT enhances CRF and cardio-circulatory function, however, evidence is limited for improvements in pulmonary-vascular function.

Svenningsen A;  Norwegian University of Science and Technology, Trondheim  Norway.
Hollekim-Strand SM; Sandmael JA; Engan H; Wisloff U; Letnes JM

European Journal of Preventive Cardiology. 33(13):2467-2476, 2026 Sep 22.

AIMS: The aim of this study was to present sex-specific reference data for
peak oxygen uptake (VO2peak) in Norwegian patients with coronary artery
disease (CAD) undergoing cardiac rehabilitation and examine its
association with major adverse cardiovascular events (MACEs).

METHODS AND RESULTS: We retrospectively analysed treadmill
cardiopulmonary exercise test (CPET) data from 1651 CAD patients (21%
women; mean (SD) age 61 (9) years) attending inpatient cardiac
rehabilitation (2004-2022). Patients were categorized by index event:
myocardial infarction (MI), coronary artery bypass grafting (CABG), or
percutaneous coronary intervention/pharmacologically treated CAD
(PCI/CAD). Age-, sex-, and diagnosis-specific VO2peak reference data were
generated. Associations between VO2peak and a combined MACE endpoint
(all-cause mortality, acute coronary syndrome, stroke, or heart failure)
were assessed using Cox proportional hazards models, including natural
cubic splines for assessing non-linear patterns. Men had higher VO2peak
than women (26.9 (6.7) vs. 23.2 (5.3) mL.kg-1.min-1; P < 0.001). VO2peak
was on average 2.5 and 1.7 mL.kg-1.min-1 lower per decade of age in men
and women, respectively. Patients with a previous MI had the highest
VO2peak, followed by CABG and PCI/CAD (P < 0.001). During 7880
person-years, 510 patients (36%) experienced MACE. Each 1 mL.kg-1.min-1
higher VO2peak was associated with a 7% lower MACE risk (HR [95% CI]; 0.93
[0.92-0.95]) in men and 5% (HR [95% CI]; 0.95 [0.91-0.99]) in women.
Patients in the highest cardiorespiratory fitness quartile had a 55% lower
risk compared to the lowest quartile. Associations were consistent across
CAD subcategories. Sex-specific natural cubic spline models revealed
inverse, non-linear associations.

CONCLUSION: This study provides novel sex- and diagnosis-specific VO2peak
reference values for Norwegian CAD patients and confirms VO2peak as a
strong prognostic marker, supporting its integration into routine
secondary prevention and individualized care.

Wang AP;  Mayo Clinic,  Chicago, IL, USA.
Garcia C; Schellenberg D; Griffith GJ; Ward K

Pediatric Cardiology. 47(7):2796-2807, 2026 Oct.

Cardiopulmonary exercise testing (CPET) is a cornerstone of functional
assessment in congenital heart disease (CHD), yet there are additional
important contributors to exercise limitation that are not directly
measured by CPET. This narrative review highlights the complementary
utility of spirometry, body composition analysis, and evaluation of
handgrip strength in augmenting our understanding of functional capacity
in CHD. Spirometry provides insights into restrictive lung disease
patterns prevalent in post-surgical CHD populations; body composition
analysis, especially lean mass assessment, can reveal sarcopenia not
apparent using BMI alone; and handgrip strength serves as a validated
surrogate for overall muscular function and frailty. We propose routine
integration of all three testing techniques as complements to CPET
protocols to enhance clinical assessment, guide rehabilitation, and
support prognostication in pediatric CHD patients. This review advocates
for broader adoption and standardization of these measures in clinical
settings to improve risk stratification and long-term outcomes.

Holden A; Royal Hospital for Children, Glasgow, UK.
Burns P; Devenny A; Thomson L; et al

Journal of Cystic Fibrosis. 25(5):819-826, 2026 Sep.

BACKGROUND: Improved survival in cystic fibrosis (CF) has shifted clinical
focus toward late complications, including altered body composition, bone
health and cardiopulmonary fitness. The effects of
Elexacaftor/Tezacaftor/Ivacaftor (ETI) on these outcomes in paediatric
patients remain unclear.

METHODS: This retrospective cohort study included paediatric CF patients
undergoing dual-energy X-ray absorptiometry (DXA) at annual review before
and 2 years after ETI initiation. Lean mass index (LMI), fat mass index
(FMI), lumbar spine bone mineral apparent density (LS-BMAD) and total body
less head bone mineral content (TBLH-BMC) were converted to age and
sex-adjusted standard deviation scores (SDS). Spirometry and
cardiopulmonary exercise testing (CPET) assessed lung function and
cardiopulmonary fitness. A matched CF control group not receiving
modulators was included.

RESULTS: 47 children were included (ETI n = 23, controls n = 24). LMI
declined significantly following ETI (mean change -0.64, p = 0.02) but
remained stable in controls (p = 0.36). LS-BMAD declined in the ETI group
(mean change -0.45, p = 0.009) with no change in controls (p = 0.31).
VO2peak % predicted decreased in the ETI group (median change -12%, p =
0.0018) alongside reductions in anaerobic threshold (-14%, p < 0.01) and
increased breathing reserve (+15%, p < 0.01), controls showed no
significant changes. FEV1 % predicted remained stable in both groups.

CONCLUSIONS: Despite preserved lung function, ETI treated children
exhibited declines in lean mass, trabecular bone density and
cardiopulmonary fitness, consistent with deconditioning. DXA and CPET
provide important complementary information beyond BMI and spirometry,
supporting targeted physical activity and nutritional interventions in ETI
treated paediatric CF patients.

Fadel, B., Department of Sport Medicine Clermont-Ferrand, France.
Gaucherot, A., Pereira, B., Egron, C., et al

Pediatr Res 2026 Sep 26 Online ahead of print.

BACKGROUND: Respiratory function (RF), body composition (BC), and cardiorespiratory fitness (CRF) links remain underexplored during multidisciplinary weight loss interventions (MWLI) in adolescents with obesity.
OBJECTIVES: To investigate the impact of a 16-week MWLI on resting and exercise RFs and their associations with BC and CRF.
METHODS: RFs were measured in 92 adolescents (13.1 +/- 1.19 years, 58%female, BMI 34.31 +/- 4.93 kg/m(2)) by spirometry and at several intensities during cardiopulmonary exercise tests (CPET) before MWLI (T0) and after (T1). BC and CRF were measured by dual X-ray absorptiometry and peak oxygen consumption (VO(2peak)).
RESULTS: Between T0 and T1, forced vital capacity (FVC), expiratory volume in one second (FEV1) and median expiratory flow (MEF25-75) increased (p < 0.001). Ventilatory efficiency increased (p < 0.01), while VO(2) and minute ventilation (VE) at similar calibrated exercise power outputs during exercise decreased. Body mass, total, trunk and visceral fat mass (FM) decreased while lean mass (LM) and CRF increased (p < 0.001). DeltaFVC, DeltaFEV1 and DeltaMEF25-75 were associated positively with DeltaLM% and DeltaCRF (FVC, FEV1: p < 0.001; MEF25-75: p < 0.05) and negatively with Deltatotal, Deltatrunk and Deltavisceral FM% (FVC, FEV1: p < 0.001; MEF25-75: p < 0.05). DeltaVO(2) and DeltaVE were associated negatively with DeltaLM% and DeltaCRF and positively with Deltatotal, Deltatrunk and Deltavisceral FM% (p < 0.001).
CONCLUSION: MWLI improves respiratory health and exercise tolerance in association with BC and CRF. IMPACT: This study is among the first to examine the effects of a multidisciplinary weight-loss intervention on both resting and exercise respiratory function in adolescents with obesity. The intervention improved respiratory function, body composition, and cardiorespiratory fitness. Respiratory improvements were associated with decreases in total, trunk, and visceral fat mass percentages and increases in lean mass percentage and cardiorespiratory fitness. The observed improvements in ventilatory efficiency and breathing reserve suggest a lower work of breathing and fewer ventilatory limitations during exercise, supporting multidisciplinary lifestyle interventions to improve respiratory health and exercise tolerance.

Wilson, W.M., University of Melbourne Australia
Burchill, L., Finch, S., Grigg, L. et al

ACC Adv 2026 Issue 10 Pt 2 Pages 103276

BACKGROUND: There are few proven therapies for improving exercise capacity in patients with transposition of the great arteries who have undergone an atrial switch repair.
OBJECTIVES: The objective of the study was to evaluate the effect of heart rate lowering using ivabradine on exercise capacity and quality of life in this cohort.
METHODS: In this single-center, randomized, double-blind, crossover study, patients were randomized to ivabradine or placebo for 4 weeks then crossover treatment for 4 weeks. A cardiopulmonary stress test and quality of life assessment were performed at baseline then at weeks 4 and 8. Estimates of difference were described using a mixed effects model.
RESULTS: A total of 19 patients were eligible and 10 patients completed the study. Compared to placebo, ivabradine treatment was associated with lower heart rate at baseline (65 +/- 3 beats/min on ivabradine vs 79 +/- 5 beats/min on placebo, difference -14.6 [-24, -5]; P = 0.008) and at peak exercise (131 +/- 7 beats/min vs 146 +/- 7 beats/min, difference -15.3 [-24, -6]; P = 0.003). Peak oxygen consumption was 20.4 +/- 1.2 mL/kg/min on ivabradine vs 19.2 +/- 1.2 mL/kg/min on placebo (difference +1.2 [-0.09, 2.6]; P = 0.06). Peak oxygen pulse was higher on ivabradine compared to placebo (12.5 +/- 1.2 vs 10.7 +/- 1.2 mL/beat, difference +1.7 [0.9, 2.6]; P = 0.002). Visual analog score was 73.5 +/- 5.6 on ivabradine vs 62.5 +/- 5.6 on placebo (mean difference 11.0 [-1.6, 23.6]; P = 0.08). One patient developed symptomatic bradycardia and one patient experienced phosphenes.
CONCLUSIONS: Ivabradine use in patients with transposition of the great arteries and atrial switch repair lowered peak heart rate with exercise and was associated with a higher oxygen pulse.