Jose, J.T., Lucile Packard Children’s Hospital Stanford University, Palo Alto, CA, USA.
Bernstein, D., Palaniappan, L., Leonard, M.B., et al

J Pediatr 2026 Pages 115379

OBJECTIVE: To examine how measures of cardiac, vascular, and muscle health relate to Pediatric Quality of Life Inventory (TM) (PedsQL) score in a cohort of children and adolescents with Fontan circulation.
STUDY DESIGN: We performed a cross-sectional analysis of baseline data from children and adolescents (8-19 years) with Fontan circulation enrolled in a prospective study. Participants underwent a series of tests, including a cardiopulmonary exercise test, dual-energy X-ray absorptiometry measures of appendicular lean mass index (ALMI, kg/m(2)), leg dynamometry, and the 23-item PedsQL. The survey quantifies Physical, Emotional, Social, and School functioning into 1 total score and 2 summary scores for physical and psychosocial health.
RESULTS: 135 patients (median age 12.7 [IQR 10.2, 15.6] years) completed the baseline visit. Median time from Fontan operation was 8.7 years [IQR 5.9, 12.0]. Peak VO(2) was 1309 [IQR 1070, 1670] mL/min, and indexed peak VO(2) was 31.1 [IQR 25.2, 36.1] mL/kg/min. Physical and Psychosocial PedsQL summary scores were 78.1 [IQR 67.2,90.6] and 76.7 [IQR 63.3, 90], respectively, and the total score was 76.1 [IQR 65.2, 88.0]. Absolute peak VO(2) was weakly correlated with PedsQL Physical Summary Score (rho=0.21, P=0.015), but indexed peak VO2, % predicted peak VO2, and Fontan-specific peak VO2 z-score were not ALMI z-score was -0.84 [IQR -1.56, -0.14] and positively correlated with total PedsQL score (rho=0.28, P=0.001) and the Physical Functioning domain (rho=0.30, P<0.001).
CONCLUSIONS: Skeletal muscle mass was associated with quality of life in children with Fontan circulation. The association between VO2 and physical function was attenuated with body-size normalization.

Song, Q., Department of Cardiac rehabilitation, Guangzhou, China
Bai, B., Chang, J., Jiang, Z., Lin, Z., Hu, D. & Ma, H.

Complement Ther Med 2026 Pages 103450

BACKGROUND: Anxiety and depressive symptoms are common in patients with cardiovascular disease (CVD) and are associated with poorer prognosis. Exercise-based rehabilitation may improve both psychological and cardiopulmonary outcomes in this population.
OBJECTIVE: To evaluate and compare the short-term effects of high-intensity interval training (HIIT) and moderate-intensity interval training (MIIT) in CVD patients with comorbid anxiety and/or depression.
METHODS: This retrospective real-world study screened 1,020 cardiac rehabilitation patients, of whom 112 were included in the final analysis. All participants completed a 4-week supervised outpatient HIIT or MIIT. Anxiety and depressive symptoms were assessed using the GAD-7 and PHQ-9, and cardiopulmonary fitness was evaluated by standardized cardiopulmonary exercise testing.
RESULTS: After 4 weeks, in the HIIT group, GAD-7 and PHQ-9 scores decreased by 4.4 +/- 4.3 and 3.7 +/- 4.3 points (Cohen’s d = -1.023 and -0.860; p < 0.001); in the MIIT group, the corresponding reductions were 4.8 +/- 4.9 and 3.5 +/- 4.0 points (Cohen’s d = -0.980 and -0.875; p < 0.001). Both groups also demonstrated significant improvements in multiple cardiopulmonary parameters (all p < 0.05). Nominal between-group differences were observed for AT VO(2) and PETCO(2) before multiplicity correction, but neither difference remained statistically significant after FDR correction.
CONCLUSIONS: In clinical practice, short-term HIIT and MIIT may both be feasible strategies to alleviate psychological symptoms and improve cardiopulmonary fitness in CVD patients with comorbid anxiety or depression.

Di Gioia G; Institute of Sports Medicine and Science, Rome, Italy.
Ferrera A; Spera FR; Pelliccia A; Squeo MR

International Journal of Cardiology. 464:134785, 2026 Dec 01.

BACKGROUND: Low QRS voltage (LQRSV) is an uncommon electrocardiographic
finding in able-bodied athletes and it is investigated to exclude
underlying cardiomyopathy. Its prevalence and clinical meaning in
Paralympic athletes (PA), particularly those with spinal cord injury
(SCI), remain unknown.

OBJECTIVES: To describe the prevalence of LQRSV in elite PA and to
explore its associations with cardiac structure and functional parameters,
with attention to differences between athletes with and without SCI.

METHODS: 193 healthy Olympic PA underwent anthropometric assessment,
12-lead-ECG, comprehensive echocardiography, and cardiopulmonary exercise
testing. Athletes were classified according to disability (SCI vs.
non-SCI). LQRSV was defined according to international criteria.

RESULTS: PA had mean age 32.7 +/- 9.7 years, and 44% were females. LQRSV
was identified in 22 athletes (11.4%), with a higher prevalence among
those with SCI (27.6% vs. 4.6% in NSCI, p < 0.0001). Athletes with LQRSV
were older (p = 0.01), frequently involved in skill-based sports (p <
0.0001). Compared with athletes with normal ECG voltages, they exhibited
reduced exercise performance (VO2 max 23.1 +/- 10.5 vs. 37 +/- 14.5
mL/min/kg; p < 0.0001) and lower O2 pulse (p < 0.0001). Echocardiography
revealed smaller left ventricular (LV) volumes and LV mass, while systolic
function was preserved (p = 0.488). Among SCI athletes, those with LQRSV
demonstrated lower W/kg (p = 0.039), lower LV mass (p = 0.037) and higher
fat mass (p = 0.035). At multivariable logistic regression analysis, SCI
emerged as the only independent correlate of LQRSV (p = 0.011).

CONCLUSIONS: LQRSV shows an unexpectedly high prevalence in PA,
particularly those with SCI, and may reflect a cardiac phenotype
characterized by smaller chambers and reduced metabolic drive, rather than
pathological remodeling.

Foulkes SJ; College of Health Sciences, University of Alberta, Canada;
Moura-Ferreira S; Milani M; Bekhuis Y; et al

Journal of Cardiac Failure. 32(10):1715-1726, 2026 Oct.

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, VO2peak) hemodynamic responses, and peripheral oxygen
extraction (a-vO2diff).

METHODS: Patients referred to a multidsciplinary clinic for evaluation of
unexplained dyspnea and diagnosed with HFpEF after a comprehensive
clinical and hemodynamic evaluation were stratified on the basis of
whether they were in persistent/permanent AF (AFPersist; n=86), paroxysmal
AF (AFParox; n=328), or sinus rhythm (SR; n=274). Cardiopulmonary exercise
testing with simultaneous echocardiography was applied to assess the
VO2peak, a-vO2diff, and exercise hemodynamics. Groups were compared using
analysis of covariance with adjustment for age, sex, body mass index, and
the presence of hypertension and diabetes.

RESULTS: Compared with patients in SR or with AFParox, patients with
HFpEF and AFPersist had a lower VO2peak (1.3-2.4 mL/kg/min lower, P <
.001). This coincided with lower peak exercise cardiac output (CO, 0.6-1.2
L/min lower), secondary to a lesser stroke volume (14-17 mL lower, P <
.001), and a smaller left ventricular end-diastolic volume (15-18 mL
lower, P < .001) that tended to decrease during exercise. In contrast,
there was no impact of AF status on peak exercise a-vO2diff, mean
pulmonary artery pressure or the mean pulmonary artery pressure/CO slope.

CONCLUSIONS: Patients with HFpEF and AFPersist have a lower VO2peak
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

Salazar-Perez F; Universitat Internacional de Catalunya (UIC), Barcelona, Spain.
Sanz-Santiago V; de Mir-Messa I; Sardon Prado O; et al

European Respiratory Journal. 68(4), 2026 Oct.

BACKGROUND: While high-intensity interval training (HIIT) has shown
effectiveness in improving cardiorespiratory fitness (CRF) across various
chronic respiratory diseases, its impacts on individuals with
post-infectious bronchiolitis obliterans (PIBO) remain unexplored. Our aim
was to assess the effects of a home-based, remotely supervised, HIIT
programme on CRF, clinical and functional variables in patients with PIBO.

METHODS: Participants of this assessor-blinded, multicentre, randomised
controlled trial were individuals with PIBO aged 6-20 years. An exercise
(EXE) group underwent two 40-min sessions of HIIT remotely supervised in
real time per week. Sessions were continued for 16 weeks. The control
(CON) group adhered to general physical activity recommendations. The
primary outcome was peak oxygen uptake (V O2 peak), time to first
ventilatory threshold (VT1), percentage of V O2 at VT1 and ventilatory
equivalent for carbon dioxide, determined via cardiopulmonary exercise
testing on a treadmill. Secondary outcomes were lung function
(spirometry), muscle strength (dynamometry), functional capacity (30-s
sit-to-stand (30s-STS) test), body mass index and St George’s Respiratory
Questionnaire score.

RESULTS: 51 PIBO patients were enrolled (EXE group n=25; CON group n=26)
(49% females; mean+/-sd age 13.3+/-4.2 years; forced expiratory volume in
1 s -3.56+/-1.28 (z-score); V O2 peak 36.8+/-8.6 mL.kg-1.min-1). The HIIT
intervention resulted in improvements in V O2 peak (mean difference 3.39
mL.kg-1.min-1; p=0.04), time to VT1 (mean difference 1.05 min; p=0.04) and
number of repetitions in the 30s-STS test (mean difference 2.21
repetitions; p=0.04). No differences were found in the other variables.

CONCLUSIONS: Our real-time, remotely supervised HIIT intervention was
effective at significantly increasing CRF and functional capacity in
children and adolescents with PIBO.

Abbaspour Kaboudan F;  Veterans Affairs Health Care System, San Francisco, USA
Zeng S; Abrham Y; Roman J; et al

Medicine & Science in Sports & Exercise. 58(11):2570-2580, 2026 Nov 01.

PURPOSE: Volume of oxygen uptake at peak exercise ( ) is a key indicator
of cardiorespiratory fitness used to assess surgical risk and clinical
trial outcomes. However, multiple prediction equations exist for its
interpretation, often yielding inconsistent classifications of exercise
performance. We aimed to determine how different prediction equations
affect exercise performance classification and identify factors
contributing to its variability.

METHODS: We performed a post hoc analysis of cardiopulmonary exercise
testing (CPET) data collected from 332 nonsmoking flight attendants who
participated in our previous studies examining the health effects of
occupational exposure to secondhand tobacco smoke. Percent-predicted was
calculated using seven prediction equations (Fitness Registry and the
Importance of Exercise National Database, Wasserman, Hansen-Wasserman,
Study of Health in Pomerania, Jones, Bruce, and Cooper-Storer). Reduced
exercise performance was defined as < 80 percent-predicted. Agreement
across equations was assessed using Cohen’s kappa. Associations with
dyspnea (modified Medical Research Council >= 1) were examined using
C-statistics to assess the discriminative performance of prediction
equations for this patient-centered outcome. The magnitude of change in
percent-predicted when switching from one equation to another
(“recalculation magnitude”) was quantified for individual participants,
and multivariable regression modeling was used to identify demographic and
anthropometric determinants of recalculation magnitude.

RESULTS: Participants were 56 +/- 12 years old, 86% female, with body
mass index = 24 +/- 4 kg/m 2 . Depending on the prediction equation, mean
percent-predicted varied widely (83%-113%), and the prevalence of reduced
exercise performance ranged from 7% to 51%. Agreement across equations
ranged from slight to substantial (kappa = 0.10-0.79). At an individual
level, switching between equations recalculated percent-predicted by -93%
to +84%, leading to bidirectional exercise performance reclassification of
6.6%-45.5% of participants. Body mass index was the strongest determinant
of recalculation magnitude, followed by age and sex. The discrimination
accuracy of prediction equations for dyspnea was modest (area under the
curve = 0.56-0.71), with the Study of Health in Pomerania equation showing
the best performance.

CONCLUSIONS: Different prediction equations yielded materially different
percent-predicted values and frequently changed exercise capacity
classification in a bidirectional manner. The observed discordance appears
to arise in substantial part from limitations in how demographic and
anthropometric factors, particularly body size, are modeled across
equations, underscoring the need for improved reference standards that
better capture physiological variability.

Zhang SS; Department of Cardiology, Beijing, China,
Jiang LY; Zuo HJ; Liu WJ

Cardiovascular therapeutics. 2026(1):e3611934, 2026.

BACKGROUND: Cardiorespiratory fitness (CRF) is a powerful predictor of
cardiovascular morbidity and mortality. The cardiopulmonary exercise test
(CPET) is considered a gold standard in assessing CRF. Patients with
myocarditis are recommended to abstain from exercise because of the risk
of sudden cardiac death (SCD). Therefore, the clinical benefit of
exercise-based cardiac rehabilitation (CR) has not been previously
established in this population.

OBJECTIVE: The aim of this study is to assess the CRF of myocarditis and
the safety and effectiveness of an exercise-based CR program in these
populations.

METHOD: A total of 70 consecutive patients with a diagnosis of
myocarditis admitted to Tongji Hospital, Tongji Medical College, Huazhong
University of Science and Technology between October 2021 and December
2024 were enrolled in the current study. CPET was performed within 3-6
months of hospital discharge. The exercise-based CR program was performed
for 3 months. The protocol included biomarker analysis, CPET, and
standard-of-care echocardiography (including resting left ventricular
ejection fraction and global longitudinal strain [GLS]). Data were
collected at admission and 3 months after discharge.

RESULTS: A total of 70 patients with myocarditis were enrolled. Among
them, 47 patients completed the rehabilitation program and had complete
follow-up assessments, including cardiopulmonary exercise testing, and
were included in the final analysis. In comparison with NFM, patients with
FM were more often female, and had higher levels of creatine kinase (CK),
lactate dehydrogenase (LDH), urea nitrogen (UN), N-terminus probrain
natriuretic peptide (NT-proBNP), fasting blood glucose (FBG), and white
blood cell (WBC). For FM, echocardiography revealed more frequently signs
of left ventricular (LV) dysfunction in the form of a reduced ejection
fraction (p < 0.01), and lower GLS (p < 0.01) in contrast to NFM. CPET
results showed that FM patients had markedly lower exercise capacity,
impaired ventilatory efficiency, and pulmonary function (p < 0.05). After
the 3-month exercise-based CR program, both groups demonstrated
significant improvements in peak VO2, peak workload, and MVV. However, no
significant between-group differences were observed in the magnitude of
improvement in CRF.

CONCLUSION: CRF was substantially impaired in patients recovering from
myocarditis, particularly among those with fulminant presentations.
Participation in a structured 3-month exercise-based CR program was
feasible and was associated with favorable changes in exercise capacity
and cardiopulmonary performance.

Mosen H; Department of Clinical Physiology, Lund, Sweden.
Szekely A; Steding-Ehrenborg K; Akil Engblom S; et al

American Journal of Cardiology. 278:30-37, 2026 Nov 01.

Chronic coronary syndrome (CCS) is associated with reduced stress
perfusion, a predictor of adverse cardiovascular outcome. To what extent
myocardial perfusion is related to cardiorespiratory fitness is not
completely known. The aim was to investigate if change in myocardial
perfusion correlates to change in aerobic capacity after
revascularization. Sixty-two patients with suspected or established CCS
underwent cardiopulmonary exercise testing (CPET) and [13N]NH3 positron
emission tomography (PET) before and after elective invasive coronary
angiography. Thirty-six patients were revascularized and 26 were not. The
angiographer was blinded to the results from CPET and PET. Myocardial
perfusion was defined as decreased when below 2 ml/min/g and as myocardial
perfusion reserve (MPR) <2. Change in oxygen uptake at submaximal effort
(VO2 at AT) correlated positively to change in MPR in revascularized
patients (r = 0.36, p = 0.04), but not in conservatively treated patients
(r = 0.03, p = 0.90). Change in VO2 peak, however, did not correlate to
change in myocardial perfusion in any of the groups. Myocardial perfusion
at stress and MPR increased significantly after revascularization, when
baseline perfusion was decreased (p = 0.01 stress and p = 0.001 MPR,
respectively). Furthermore, the number of patients with exercise-induced
angina decreased significantly for the revascularized patients (42%
(14/33) at baseline versus 3% (1/33) at follow-up, p <0.001) whereas half
of the conservatively treated patients still had exercise-induced angina
at follow-up (42% (10/24) at baseline versus 21% (5/24) at follow-up, p =
0.12). In conclusion, change in myocardial perfusion correlates with
change in submaximal aerobic capacity after revascularization and
revascularization reduces exercise-induced angina.

Mackay Z; Yale School of Medicine, USA
Shah S; Villalobos JG; Latif N; et al

American Journal of Physiology – Heart & Circulatory Physiology.
331(5):H1485-H1494, 2026 Nov 01.

This single-center cohort study sought to evaluate the association between
myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and angina
with nonobstructive coronary arteries (ANOCA), by determining the observed
frequency of ME/CFS among patients with ANOCA diagnosed by coronary
function testing (CFT). In addition, we performed an exploratory analysis
of the diagnostic utility of invasive cardiopulmonary exercise testing
(iCPET) in ME/CFS patients with CFT-confirmed ANOCA, with the aim of
identifying the predominant physiological mechanism responsible for
exertional limitation in this population. Systematic medical record review
of 261 patients with CFT-confirmed ANOCA was performed using standardized
diagnostic criteria to identify concurrent ME/CFS diagnosis. ME/CFS was
identified in 47 patients, representing an observed frequency of 18%. The
only statistically significant difference between ANOCA patients with and
without ME/CFS was a higher frequency of connective tissue disease in the
ME/CFS group (P = 0.0221). In a separate cohort of 27 patients with ME/CFS
who underwent iCPET, 24 patients (89%) had CFT-confirmed ANOCA. The
diagnosis of ANOCA by CFT prompted a change in medical management in 81%
of patients in this cohort. iCPET revealed a primary peripheral limitation
to exercise, characterized by impaired peak systemic oxygen extraction
despite normal peak oxygen delivery. This study demonstrates a clinically
significant association between ME/CFS and ANOCA. These findings
underscore the clinical value of CFT in patients with ME/CFS and
exertional chest pain and highlight iCPET as a complementary tool for
hemodynamic phenotyping in this population. Prospective studies
incorporating simultaneous CFT and iCPET with molecular phenotyping are
warranted. NEW & NOTEWORTHY This study demonstrates a clinically
significant association between myalgic encephalomyelitis/chronic fatigue
syndrome (ME/CFS) and angina with nonobstructive coronary arteries
(ANOCA), with 18% of patients with coronary function testing-confirmed
ANOCA meeting diagnostic criteria for ME/CFS. Invasive cardiopulmonary
exercise testing (iCPET) in patients with concurrent ME/CFS and ANOCA
reveals a primary peripheral, not cardiac, limitation to exercise. These
findings highlight the complementary roles of coronary function testing
and iCPET for hemodynamic phenotyping in this underrecognized patient
population.

Thornton GD; Institute of Cardiovascular Science University College London, UK
Bennett JB; Aziminia N; Tapia L; Birkinshaw A; et al

JAMA Cardiology. 11(10):981-990, 2026 Oct 01

Importance: Patients undergoing aortic valve replacement (AVR) for chronic
severe aortic regurgitation (AR) based on current guideline-based
thresholds may have irreversible myocardial scarring.

Objective: To quantify reverse remodeling, functional recovery, and
symptomatic change after AVR and assess whether myocardial fibrosis is
associated with incomplete recovery.

Design, Setting, and Participants: In this prospective longitudinal
observational study, patients with chronic severe AR referred for AVR by a
cardiology team were included. Key exclusion criteria were previous valve
surgery, moderate or greater valve disease, and other primary
cardiomyopathies. Included patients underwent paired biomarkers,
echocardiography, cardiopulmonary exercise testing, and cardiovascular
magnetic resonance (CMR) at baseline and at a median of 7 months after
AVR. The study took place at 2 tertiary cardiothoracic centers in London,
United Kingdom, with enrollment from August 2021 to October 2023. Data
were analyzed from January to April 2026.

Exposure: AVR.

Main Outcomes and Measures: Left ventricular (LV) reverse remodeling
(change in LV end-diastolic volume [LVEDV] and LV mass) post-AVR and
preoperative correlates of incomplete recovery, with prespecified focus on
CMR fibrosis markers (late gadolinium enhancement [LGE] and extracellular
volume [ECV]).

Results: Seventy-two patients (median [IQR] age, 60 [6-70] years; 59
[82%] male, 35 [49%] with bicuspid aortic valve) completed paired studies.
Median (IQR) regurgitant volume fell from 61 (38-83) mL to 5 (3-8) mL;
median (IQR) LVEDV fell 44% from 273 (211-307) mL to 153 (130-177) mL; and
median (IQR) LV mass fell 21% from 200 (159-226) g to 158 (137-184) g (all
P < .001). Indexed intracellular volume declined 21% and indexed
extracellular volume 15% (26 mL/m2 to 22 mL/m2; P < .001), raising
extracellular volume fraction (ECV%) from 27.4% to 29.1% (P < .001). LGE
as a percentage of LV mass was unchanged (2.3% to 2.4%; P = .36); baseline
LGE burden was associated with less regression of LV mass (chi22 = 29.4; P
< .001) and LVEDV at 7 months (chi21 = 7.9; P = .007). New York Heart
Association class and quality of life improved (median [IQR] EQ-5D index
improved from 0.89 [0.78-1.00] to 0.94 [0.81-1.00]; P < .001), but maximum
oxygen consumption was unchanged (22.6 mL/kg/min to 21 mL/kg/min; P =
.08). N-terminal pro-B-type natriuretic peptide decreased slightly (228
pg/mL to 198 pg/mL; P = .27), with a larger fall in patients with evidence
of decompensation (n = 31; 469 pg/mL to 279 pg/mL; P = .02).

Conclusions and Relevance: In this study, AVR was associated with
substantial reverse remodeling at 7 months, including regression of
hypertrophy and a fall in indexed extracellular (matrix) volume; the
extracellular volume fraction rose, as cellular regression outpaced matrix
regression. Focal scar, as a proportion of myocardium, was unchanged.
Preoperative focal scar was independently associated with less recovery
and may mark incomplete remodeling. Objective functional recovery did not
improve at this time point.