Inoue A; Sidia Institute of Science and Technology, Brazil
Soares JPF; Antunes-Santos F; Ferreira A; Goncalves A; Alcantara JA; Dos Santos MR

JMIR Cardio. 10:e81917, 2026 Apr 16.

Background: Photoplethysmography-based smartwatches are increasingly used
for continuous heart rate (HR) monitoring. Their accuracy has been
demonstrated at rest or during low-intensity activity, but data are scarce
for maximal-intensity exercise, when motion artifacts and rapid
hemodynamic changes can degrade the photoplethysmography signal.
Validating these devices under such demanding conditions is essential
before they are applied to clinical exercise testing, athletic training,
or remote health monitoring.

Objective: This study aimed to evaluate the validity of the Samsung
Galaxy Watch6 (GW6) in estimating HR throughout a graded, maximal ramp
cardiopulmonary exercise test performed on a treadmill. A secondary aim
was to explore whether measurement error varies across 5 predefined
intensity zones (50%-60%, 60%-70%, 70%-80%, 80%-90%, and 90%-100% of the
maximum HR determined individually for each participant).

Methods: Overall, 55 healthy adults (30 men, 25 women; mean age 30.3, SD
8.2 years) completed a symptom-limited incremental treadmill protocol to
volitional exhaustion. Simultaneous HR recordings were obtained from the
GW6 (left arm) and a Polar H10 chest strap monitor, which served as the
reference standards. For each intensity zone, the following agreement
indices were computed: intraclass correlation coefficient (ICC), median
absolute error, median absolute percentage error, and root mean squared
error. Bland-Altman analysis was performed to quantify the mean bias and
95% limits of agreement between the GW6 and the Polar H10. Statistical
significance was set at P<.05.

Results: Agreement between the GW6 and Polar H10 varied across exercise
intensities. ICC indicated moderate to good agreement at low to moderate
intensities (ICC=0.71 at 50%-60%; ICC=0.89 at 60%-70%; ICC=0.54 at
70%-80%; and ICC=0.64 at 80%-90% HRmax), and at 90%-100% of HRmax the
agreement was good-to-excellent (ICC=0.90). Absolute error metrics showed
stable or reduced errors with increasing intensity, with median absolute
error consistently around 1-3 bpm and median absolute percentage error
declining from 2.90% at 50%-60% HRmax to 0.60%-0.75% at >=70% HRmax. Root
mean squared error ranged from 4.62 to 4.88 bpm across intensity zones.
Bland-Altman analysis showed that the GW6 consistently underestimated HR
compared with the Polar H10, with an overall mean bias of -2.67 bpm and
wide limits of agreement (-16.90 to 11.57 bpm). This negative bias was
present across all HR zones. The agreement was adequate for group-level
comparisons but displayed substantial individual variability.

Conclusions: The GW6 provides a good degree of validity for HR monitoring
during a maximal treadmill cardiopulmonary exercise test in healthy young
adults. Although measurement error increases modestly at near-maximal
workloads, absolute errors remain well within clinically acceptable
thresholds. These findings support the potential use of GW6 as a
convenient, noninvasive alternative for HR tracking in laboratory-based
exercise testing.

Ozeki T; Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
Ito T; Hosoba S; Shintani A; Orii M; Tokoro M; Shimizu S; Sawaki
S; Usui A; Mutsuga M

General Thoracic & Cardiovascular Surgery. 74(4):369-375, 2026 Apr.

OBJECTIVES: Few physiological assessments are available for patients who
undergo mitral valve repair for severe mitral regurgitation (symptomatic
or asymptomatic). The aim of the study was to evaluate change in exercise
tolerance as a means of physiological assessment following mitral valve
repair.

METHODS: We studied 41 consecutive patients who received elective
isolated mitral valve repair for severe mitral regurgitation in a
minimally invasive manner via a completely endoscopic platform and who
underwent cardiopulmonary exercise testing in our institution between
February 2018 and August 2019. There were 21 asymptomatic (group A) and 20
symptomatic (group S) patients. Physiological assessment was performed by
cycle ergometer cardiopulmonary exercise testing pre-operatively and at
approximately 6 months post-operatively.

RESULTS: Mean age was 59 +/- 11.6 years and 24 patients were male
(58.5%). Overall, there was no significant change in peak oxygen
consumption or anaerobic threshold after surgical repair. There were no
intergroup differences in terms of peak oxygen consumption, anaerobic
threshold, ventilation/carbon dioxide production, or gas exchange ratio.
There were no intergroup differences in any transthoracic
echocardiographic variable except for post-operative left atrial dimension
(group A: 35.2 +/- 5.9 vs. group S: 39.8 +/- 6.2, p = 0.01).

CONCLUSIONS: There was no statistically discernible change in functional
capacity at 6-12 months after endoscopic mitral valve repair. The
physiological assessment found no improvements in cardiopulmonary exercise
testing values post-operatively despite improvement of the symptoms.

Griffith, Garett J;  Mayo Clinic, Rochester, MN, USA.
Wang, Alan; Ward, Kendra.

Cardiology in the Young. 36(2):244-251, 2026 Feb.

BACKGROUND: Exercise capacity (VO2peak) predicts mortality in adult
patients with CHD. There is a lack of paediatric exercise capacity data
based on specific CHD lesions, limiting the ability to contextualise
interpretation based on expected performance during testing. The primary
aim of this study was to establish VO2peak percentiles for paediatric
patients with repaired CHD undergoing treadmill-based cardiopulmonary
exercise testing (CPET).

METHODS: Retrospective analysis of CPET data from 2004 to 2022. CPETs
were analysed for patients with CHD aged 6-18 years. Patients with
repaired CHD were categorised based on their most haemodynamically
significant CHD lesion. Percentiles and age-based trends were plotted for
each group.

RESULTS: A total of 887 patients were included. CHD patients were divided
into ten diagnostic subgroups. The mean percent expected VO2peak for each
of the subgroups were as follows: Atrial and ventricular septal defect
(94.5 +/- 25.1%), pulmonary valve repair (88.1 +/- 18.4%), aortic valve
repair (92.7 +/- 16.4%), tricuspid and mitral valve repair (81.3 +/-
20.4%), coarctation of the aorta (93.6 +/- 18.8%), transposition of the
great arteries (90.5 +/- 19.4%), double outlet right ventricle and truncus
arteriosus (80.5 +/- 16.2%), tetralogy of Fallot (85.6 +/- 20.9%), left
ventricle dominant Fontan (74.7 +/- 18.3%), and right ventricle dominant
Fontan (75.7 +/- 16.7%).

CONCLUSION: There is a varying degree of reduced exercise capacity in
paediatric patients with repaired CHD. Univentricular hearts and tricuspid
and mitral valve repair have the lowest VO2peak. These CHD-specific
percentiles may help providers risk-stratify and counsel patients with
CHD.

Rato J; Pediatric Cardiology Department, Hospital de Santa Cruz
– Unidade Local de Saude Lisboa
Cordeiro S; Anjos R

Cardiology in the Young. 36(2):332-337, 2026 Feb.

INTRODUCTION: The Fontan procedure enables survival in individuals with
univentricular physiology but is associated with progressive circulatory
failure. Identifying predictors of adverse outcomes is essential to
improve long-term management. This study evaluated five-year outcomes and
baseline predictors of major events in a previously characterised
paediatric and young adult Fontan cohort.

METHODS: This retrospective longitudinal study included 51 patients
(median age 18 years, interquartile range 11) who underwent comprehensive
evaluation between 2018 and 2019, including echocardiography with atrial
strain analysis and cardiopulmonary exercise testing. The composite
outcome comprised death, heart transplantation listing, hospitalisation
for heart failure, or conduit thrombosis. Univariable and multivariable
logistic regression identified predictors of adverse outcomes.

RESULTS: During a five-year follow-up, 7 patients (14%) met the composite
outcome. Those with events had lower body mass index (19.8 kg/m2 [4.1] vs
16.9 [3.6]; p = 0.007), lower atrial conduit strain (10.95% [8.95] vs 2.8
[6.2]; p = 0.011), reduced peak oxygen uptake, and higher VE/VCO2 slope.
In multivariable analysis, lower body mass index (OR 0.49, 95% CI
0.26-0.93; p = 0.028) and reduced atrial conduit strain (OR 0.70, 95% CI
0.51-0.96; p = 0.026) were independently associated with adverse outcome,
with excellent model discrimination (AUC = 0.95).

DISCUSSION: Both nutritional status and atrial functional parameters
demonstrated a strong association with the outcome. Reduced atrial conduit
strain, reflecting diastolic dysfunction, and lower body mass index,
possibly reflecting myopenia or cachexia, identified higher-risk patients
and potential areas for intervention. Routine assessment of atrial
function and nutritional status should be integrated into clinical
surveillance and risk stratification of the Fontan population.

Chang Y; The First Hospital of Hebei Medical
University, Shijiazhuang, Hebei, China.
Li L; Ma Y; Zhou J; Wang L; Zhan Y

Catheterization & Cardiovascular Interventions. 107(5):1369-1375, 2026

BACKGROUND: The management of asymptomatic patients with severe aortic
stenosis (AS) remains challenging. While transcatheter aortic valve
replacement (TAVR) is established for symptomatic AS, its objective
functional benefits in asymptomatic individuals are not well-defined.

AIMS: To evaluate the safety and hemodynamic efficacy of TAVR in
asymptomatic patients with severe aortic stenosis and to objectively
quantify their functional recovery using cardiopulmonary exercise testing
(CPET).

METHODS: In this single-center retrospective study, 156 asymptomatic
patients with severe AS undergoing TAVR with the VitaFlow valve were
enrolled. Safety endpoints were adjudicated per Valve Academic Research
Consortium (VARC-3) criteria. Efficacy was assessed via serial
echocardiography and brain natriuretic peptide (BNP) levels at baseline, 1
day, 7 days, 3 months, and 12 months. Functional capacity was objectively
quantified using CPET at baseline, 1 month, and 12 months.

RESULTS: Procedural success was 100% with no mortality, stroke, or major
complications. Hemodynamics improved immediately (mean gradient: 51.6 +/-
11.7 to 13.7 +/- 7.2 mmHg, p < 0.001) and remained stable at 12 months.
BNP levels decreased significantly from 7 days onward (p < 0.05). CPET
revealed substantial improvements in functional capacity: peak oxygen
uptake (VO2) increased from 15.6 +/- 3.6 to 19.8 +/- 4.0 mL/kg/min (p <
0.001), anaerobic threshold (AT) increased, and ventilatory efficiency
(VE/VCO2 slope) decreased (all p < 0.001). The incidence of
exercise-induced adverse events also significantly declined.

CONCLUSIONS: TAVR is a safe and highly effective intervention for
asymptomatic severe AS, resulting in immediate hemodynamic improvement and
sustained, objective enhancement of functional capacity, as rigorously
quantified by CPET.

Weber V; Johannes Gutenberg University, Mainz, Germany.
Lopez DA; Ochmann DT; Zentgraf S; Nagele M; Neuberger EWI;
Schomer E; Simon P; Hillen B

Scientific Reports. 16(1), 2026 Mar 28.
Headings added by Dr Older

Background Infrared thermography (IRT) has recently gained attention in the field of
exercise physiology, due to its ability to monitor thermoregulatory and
cardiopulmonary responses non-invasively and in real time during physical
exercise. However, the reproducibility of intra-individual measurement and
standardization of region-of-interest selection in relation to the acute
exercise response remain inconclusive.
Aims This study aimed to examine the
reproducibility and physiological relevance of specific skin temperature
(TSK) metrics processed automatically using deep learning-assisted IRT
during running, and to synchronize these metrics with cardiopulmonary and
thermoregulatory parameters.
Methods Eleven endurance-trained individuals
performed three 46-min running sessions over 2 days, with the same average
external load but different intensity distributions. Individual anaerobic
threshold velocity (vIAT), previously determined by cardiopulmonary
exercise testing, was used to prescribe running intensity. During
exercise, oxygen consumption (VO2), core temperature (TCORE), heart rate
(HR) and different TSK metrics, including non-vessel (TNV), cutaneous
arterial perforator (TP), and superficial vein patterns, were continuously
measured.
Results All TSK metrics displayed consistent temporal dynamics aligned
with external load, but their absolute temperature levels differed
systematically. During intermittent running and recovery, TP exhibited
robust correlations with HR and VO2 (r = – 0.63 to – 0.9, p < 0.001), and
TP entropy showed consistent associations with TCORE during the warm-up (r
= 0.59-0.83, p < 0.001). This indicates uniform response patterns across
the cohort. In contrast, TNV demonstrated heterogeneous correlations with
TCORE, depending on individual exercise capacity. A strong inverse
correlation was identified between TNV and vIAT (r = – 0.74 to – 0.88, p
<= 0.009) and individuals with higher vIAT demonstrated greater TCORE-TNV
gradients during running. Measurements of TNV demonstrated high
reproducibility, with intra-individual ICC(3,1) values of 0.89 for
recovery and 0.76 for warm-up, and no statistically significant
differences between the three sessions.
Conclusions Deep learning-assisted IRT
provides reproducible, physiologically consistent metrics across repeated
exercise sessions, regardless of the day or prior load. Distinct TSK
metrics capture both uniform and individual-specific thermoregulatory
responses. Variability in peripheral temperature regulation is more
strongly associated with running velocity at the individual anaerobic
threshold than with maximal cardiorespiratory fitness

Takahashi S; Department of Cardiology, Sakakibara Heart Institute
Nakayama A; Nanasato M; Isobe M

Environmental Health & Preventive Medicine. 31:26, 2026.

BACKGROUND: Although marital status is a key social determinant of health,
its prognostic relevance in cardiopulmonary exercise testing (CPX) cohorts
remains unclear. We aimed to evaluate the association between marital
status and mortality risk in patients with cardiac disease (CD) who
underwent CPX.

METHODS: This retrospective, single-center observational study involved
consecutive patients with CD who underwent post-discharge CPX between 2008
and 2020. Participants (mean age: 69 years; 73% male) were categorized as
either unmarried (never married, divorced, or widowed) or married. The
primary outcome was all-cause mortality, and the secondary outcome was
cardiovascular mortality. We used Cox proportional hazards models to
estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).
Model 1 was adjusted for age and sex to estimate the overall association
between marital status and outcomes. Model 2 was adjusted for Model 1
covariates and peak VO2 to account for objectively measured exercise
capacity.

RESULTS: Of 4,681 patients analyzed, 1,117 were unmarried and 3,564 were
married. In Model 1, being married was associated with a lower risk of
all-cause mortality (aHR: 0.75, 95% CI: 0.62-0.91, P < 0.001). This
association persisted after adjusting for peak VO2 in Model 2 (aHR: 0.79,
95% CI: 0.65-0.96, P = 0.002). For cardiovascular mortality, the estimates
were consistent in direction (Model 1; aHR: 0.64, 95% CI: 0.44-0.93, P =
0.019, Model 2; aHR: 0.69, 95% CI: 0.47-1.02, P = 0.061).

CONCLUSIONS: In a large CPX cohort of patients with CD, married status
was associated with a lower risk of all-cause mortality. The association
was attenuated but remained after adjustment for peak VO2, suggesting that
differences in exercise capacity may contribute but do not fully account
for the observed association. Marital status should be interpreted as a
social marker rather than a causal or interventional exposure, and future
studies should clarify modifiable factors related to prognosis.

Soares ZV; Federal University of Espirito Santo (UFES), Vitoria, ES, Brazil.
Gasparini Neto VH; Ferreguetti Costa AK; Brum L; Nascimento Dos
Santos Neves L; Barbieri RA; Leite RD; Carletti L

Journal of Bodywork & Movement Therapies. 46:157-167, 2026 Jun.

OBJECTIVE: To investigate the physiological and perceptual responses to
the cardiopulmonary exercise test with elastic resistance (CPxEL), using
the traditional treadmill cardiopulmonary exercise test (CPx) as the
standard reference.

METHODS: Twenty-seven physically active adults (57 +/- 7 years; both
sexes) performed two maximal cardiopulmonary exercise tests in randomized
order, seven days apart: treadmill CPx and CPxEL involving back-and-forth
movements against elastic resistance. Cardiorespiratory variables, heart
rate, and ratings of perceived exertion (central and peripheral) were
assessed. A verification phase was performed to confirm maximal
physiological responses.

RESULTS: At the first ventilatory threshold (VT1), CPxEL showed higher
oxygen uptake (V O2) (15.8 +/- 3.0 vs 12.7 +/- 3.3 ml kg-1.min-1; P =
0.02) and heart rate (HR) (115 +/- 12 vs 105 +/- 11 bpm; P = 0.01). At the
second ventilatory threshold (VT2), peripheral effort was greater for
CPxEL (Z = -2.38; P = 0.02). At maximal effort, the respiratory exchange
ratio (RER) was higher in the CPx (P < 0.05), and peripheral exertion
remained higher in CPxEL (Z = -1.97; P = 0.05).

CONCLUSION: CPxEL is a feasible method for identifying ventilatory
thresholds and VO2max, and may be applied to prescribing aerobic exercise
with elastic resistance in middle-aged adults. However, it elicits
distinct physiological and perceptual responses compared with the CPx and
the two protocols should not be used interchangeably. Further studies are
needed to confirm the accuracy and safety of CPxEL in different clinical
populations

Holland JL;  Radcliffe Department of Medicine, University of Oxford, Oxford, UK.&
Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, UK.
Cowie P; Gardner L; Mulae J; Richards S; Holdsworth DA

BMJ Military Health. 172(2):140-147, 2026 Mar 20.

INTRODUCTION: Abnormal cardiorespiratory symptoms and investigative
findings in service personnel typically result in prolonged investigation
and occupational restriction. This analysis aimed to assess the impact of
the Oxford Military Cardiopulmonary Exercise Testing Clinic (OMEC), which
investigates such symptoms and findings, on occupational recommendations.

METHODS: A service evaluation was conducted on all OMEC attendances over
a 5-year period. Referral indication and occupational grading,
demographics, exercise testing parameters, clinical diagnosis and
occupational recommendation were recorded.

RESULTS: 141 individuals were reviewed. Mean age was 36 (+/-11.3) years,
and 91% were male. Median waiting time for an appointment was 14.4 weeks
(cf NHS 17.4 weeks). Individuals were referred for dyspnoea (22.1%),
syncope (11.4%), chest pain (8.1%) (referred to as ‘higher risk’ symptom
group), and pre-syncope (8.1%), palpitations (8.1%), and fatigue and/or
exercise intolerance (6.0%) (referred to as ‘lower risk’ symptom group).
34% were asymptomatic with incidental findings on cardiac screening
investigations. Reduced exercise capacity was rare, affecting only 11% of
individuals, which was borderline/mild at worst.Median peak VO2 (as a
percentage of the predicted peak) was lower in the higher-risk symptom
group than in the lower-risk symptom group (97.8% vs 121%; p<0.001). This
was also seen for median workload as %PP (82.6% vs 98.0%; p<0.001). 80.5%
of patients were given an immediate occupational recommendation; 78% of
which were favourable outcomes (ie, a recommended occupational upgrade
(72%) or to remain fully deployable (6%)).

CONCLUSION: OMEC is tailored to the unique needs of the military
population, providing outcomes that support operational requirements.
Despite geographical distribution and operational commitments, OMEC
waiting time is equivalent to the NHS, with the great majority of patients
upgraded after attendance. These findings establish OMEC as a benchmark
for military-specific clinical services based in public (NHS) hospitals,
highlighting its role in facilitating rapid and effective occupational
management.

Lee MMY; University of Glasgow, Glasgow, UK
Goldie FC; Henderson AD; Masri A; Olivotto I; Coats CJ

Progress in Cardiovascular Diseases. 94:16-26, 2026 Jan-Feb

AIMS: Data on cardiac myosin inhibitors (CMIs) in obstructive hypertrophic
cardiomyopathy (oHCM) are rapidly emerging. This systematic review and
meta-analysis evaluated the efficacy and safety of CMIs in randomized
placebo-controlled trials.

METHODS: Phase 3 randomized placebo-controlled trials published up to
22-Apr-2025 were included. Outcomes extracted included symptoms,
cardiopulmonary exercise testing (CPET), biomarkers, transthoracic
echocardiography (TTE), cardiovascular magnetic resonance (CMR), and
safety data. Frequentist (common/fixed effect, random) and Bayesian
meta-analyses were performed using trial-level data to pool estimates of
effects.

RESULTS: Four randomized placebo-controlled trials involving 726 patients
with oHCM were included (444 mavacamten/placebo, 282 aficamten/placebo).
Trial follow-up durations ranged from 16 to 30 weeks. In common/fixed
effects meta-analyses, CMIs were associated with a greater proportion
achieving >=1 NYHA improvement [difference 36 % (95 % CI 29, 43)] and an
increase in KCCQ-CSS [8.4 (6.6, 10.2) points] versus placebo. CMIs
significantly improved several CPET parameters including increased peak
oxygen consumption [1.6 (1.0, 2.1) mL/kg/min] and reduced VE/VCO2 [-2.0
(-2.7, -1.3)]. CMIs significantly reduced NT-proBNP [-79 % (-81 %, -77 %)]
and hs-cTnI [-50 % (-54 %, -46 %)]. CMIs led to significant reductions in
resting LVOT-G [-40 (-45, -35) mmHg] and favourable cardiac remodelling in
other TTE and CMR parameters. Although CMIs increased the likelihood of
LVEF <50 %, consistent with its known mechanism of action, none of these
patients developed heart failure. No significant differences were seen in
safety outcomes.

CONCLUSIONS: Mavacamten and aficamten significantly improve symptoms,
enhance exercise performance, improve cardiac biomarkers, reduce LVOT
obstruction, and promote favourable cardiac remodelling. These findings
suggest a class effect of CMIs.