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.

Nieto-Jimenez, C., School of Physical Therapy, University Andres Bello, Viña del mar, Chile.
Naranjo-Orellana, J., Medina-Porcile, C.L., Gawn, J., et al

Physiol Int 2026

BACKGROUND: Ventilatory thresholds (VT1 and VT2) determined from gas-exchange criteria during cardiopulmonary exercise testing (CPET) provide reference points for exercise-intensity prescription, but their routine use is limited in applied settings. Detrended fluctuation analysis alpha 1 (DFA-alpha1) has emerged as a potential non-invasive marker of physiological transitions during exercise.
OBJECTIVE: To quantify and compare DFA-alpha1 values against CPET-derived ventilatory thresholds and between exercise modes during constant-load swimming, cycling, and running in trained triathletes.
METHODS: Seventeen triathletes (13 men, 4 women) completed maximal incremental CPETs in swimming, cycling, and running, after which constant-load trials were undertaken at VT1 and VT2, as determined from CPET using standard ventilatory criteria. R-R intervals were recorded with a Polar V800 and Polar H10 and processed in Kubios HRV Scientific v4.2.0. DFA-alpha1 was calculated using a 120-s moving window with 5-s updates. Between-modality comparisons were performed using repeated-measures ANOVA.
RESULTS: At VT1, V O2, heart rate, and PetCO2 differed by modality, whereas DFA-alpha1 did not differ significantly between swimming, cycling, and running (0.74 +/- 0.30, 0.75 +/- 0.21, and 0.65 +/- 0.20, respectively; P = 0.456). At VT2, V O2 and heart rate again differed by modality, whereas DFA-alpha1 showed no significant differences between modalities but wide between participant variability (0.42 +/- 0.13, 0.37 +/- 0.11, and 0.47 +/- 0.13, respectively; P = 0.061).
CONCLUSION: At the group level, mean DFA-alpha1 values were numerically close to previously proposed values for VT1 ( approximately 0.75) and VT2 ( approximately 0.50). However, the marked inter-individual dispersion across modalities limits the use of fixed DFA-alpha1 values for individual identification of VT1 and VT2. These findings indicate descriptive group-level correspondence rather than individual-level validity or agreement.

de Lima, F.R., Exercise Psychophysiology Research Group  São Paulo,  Brazil.
de Salles Painelli, V., Canestri, R., Santos, T.M ,.et al

Int J Sport Nutr Exerc Metab 2026 Pages 1-10

PURPOSE: We investigated whether a small dose of alcoholic beer ingested before a running exercise bout impaired performance and changed psychophysiological responses to exercise.
METHODS: After three sessions of familiarizations, 16 healthy and physically active men (25.8 +/- 5.1 years, 175.0 +/- 5.4 cm, and 76 +/- 6.5 kg) performed a 30-min running time trial in a double-blind and placebo-controlled crossover design, after ingesting either beer (alcohol 4.8% v/v; 0.3 g/kg) or nonalcoholic beer (placebo). Performance, cardiopulmonary (oxygen consumption, ventilation, respiratory exchange ratio, and heart rate), and perceptual (perceived exertion, affect, and motivation) variables were assessed throughout the trial and averaged every 5 min during exercise. Running economy was assessed during steady-state running at 8 km/hr. The data were analyzed through t tests and repeated-measures mixed models (p < .05).
RESULTS: The ingestion of beer significantly decreased the average speed by 4.7% (p = .04; d = 0.21) and total distance covered by 4.3% (p = .007; d = 0.26) when compared with placebo. The ingestion of beer also impaired the running economy by 1.1% (p = .01; d = 0.39) and increased respiratory exchange ratio throughout the exercise bout (p = .004, d = 1.07). No beer-by-time interaction effects were detected in cardiopulmonary outcomes (p > .05). CONCLUSIONS: A small dose of alcoholic beer reduced the exercise capacity of healthy individuals, likely due to an impairment in running economy.

Borghi-Silva, A., Cardiopulmonary Physiotherapy Laboratory,  São Carlos, Brazil;
Santos-de-Araujo, A.D., Montalvo, S., Christle, J.W. & Myers, J.

Prog Cardiovasc Dis 2026

BACKGROUND: Peak oxygen consumption (pVO2) has been widely recognized to identify potential pathophysiological mechanisms of exercise intolerance and to stratify risk in patients with heart failure (HF).
AIMS: To develop a non-exercise equation to estimate pVO2 (esVO2) and to determine its association with all-cause mortality.
METHODS: A total of 5176 HF patients (age 48 +/- 17 years) who underwent a CPET for clinical reasons, and were followed between May 2011, and December 1, 2023. Clinical and historical variables and forced expiratory volume in 1-s (FEV(1)) were used in a stepwise multivariate regression analysis to predict pVO2 measured from CPET. Kaplan-Meier curves and Cox proportional hazards analyses were used to determine the association between esVO2 and all-cause mortality.
RESULTS: The first esVO2 model was significantly associated with pVO2 (multiple R = 0.73, P < 0.001). Two other models considered gender separately (male: multiple R = 0.72, P < 0.001 and female (multiple R = 0.70, P < 0.001). A fourth model was proposed when spirometry is not available (age, BMI, resting SBP, HR and gender (multiple R = 0.69, P < 0.001)). The fifth proposed model included history of atrial fibrillation and previous stroke (multiple R = 0.70, P < 0.001). Kaplan-Meier survival curves differentiated patients according to esVO2 and pVO2 </= and > 14 mL/kg(-1) per min(-1). Univariate Cox proportional hazard analyses indicated significant prognostic value when esVO2 and pVO2 were </= 14 mL/kg(-1) per min(-1) (P = 0.001).
CONCLUSIONS: Multivariable nonexercise models combining spirometry and/or clinical variables commonly obtained during a clinical assessment predict pVO2 reasonably accurately in HF.

Di Gioia, G., National Italian Olympic Committee, Rome, Italy.
Ferrera, A., Ginelli, D., Maestrini, V., et al

Eur J Appl Physiol 2026
Headings by Dr Older

Background
Spinal cord injury (SCI) alters autonomic cardiovascular regulation and may limit the translation of cardiac structural adaptation into aerobic performance. Whether spinal cord neurological level modifies cardiac size-exercise coupling in elite athletes remains under investigation.
Methods
We enrolled 178 Paralympic athletes with SCI (33% high SCI, above T6). Athletes underwent transthoracic echocardiography and cardiopulmonary exercise testing. SCI level was analyzed as the main predictor of cardiac structure and exercise performance. Multivariable linear regression models were adjusted for age, sex, and body weight, with additional sensitivity analyses including sport category. Mediation analyses evaluated the role of indexed left ventricular end-diastolic volume (LVEDV/BSA), and interaction models tested effect modification of the LVEDV-VO₂max relationship by SCI level.
Results
Athletes with low SCI exhibited larger LVEDV/BSA (60.6 ± 14.7 vs. 51.9 ± 11.9 mL\m², p < 0.0001) and higher VO₂ max (31.0 ± 9.4 vs. 21.0 ± 9.3 mL\kg\min, p < 0.0001) than those with high SCI. In adjusted models, high SCI independently predicted lower VO₂max (β=-8.88, 95% CI – 11.71 to – 6.05, p < 0.0001) and O₂ pulse (β=-3.38, 95% CI – 5.07 to – 1.70, p = 0.0002), persisting after adjustment for sport category (VO₂: β=-6.64, p = 0.001; O₂ pulse: β=-1.87, p = 0.004). LVEDV/BSA partially mediated the association between SCI level and VO₂ max (β = 0.323 per mL\m², p = 0.0002).
Conclusions
A significant SCI×LVEDV/BSA interaction (β=-1.229, 95% CI – 2.548 to – 1.090, p = 0.002) indicated attenuation of cardiac size-exercise coupling in high SCI. Level of spinal cord lesion independently influences cardiac remodeling and aerobic performance and modifies how cardiac size translates into functional capacity. High-level SCI is associated with a lesion-dependent uncoupling of cardiac structure and exercise performance.

Demers, K., Maastricht University Medical Center+, Maastricht, the Netherlands.
van Kuijk, S.M.J., Pierik, M.J., Jonkers, D., Stassen, L.P.S. & Bongers, B.C.

PLoS One 2026 Issue 10 Pages e0354707

PURPOSE: To develop predictive equations for oxygen uptake at peak exercise (VO2peak) measured during a cardiopulmonary exercise test (CPET) for patients with inflammatory bowel disease (IBD) using submaximal CPET-derived parameters and the steep ramp test, along with demographic and clinical characteristics.
METHODS: This study included patients with IBD in remission or with mild-to-moderate disease activity who performed a CPET and a steep ramp test within 14 days. Submaximal CPET-derived parameters included oxygen uptake (VO2) at the ventilatory anaerobic threshold (VAT) and oxygen uptake efficiency slope (OUES), while the outcome of the steep ramp test was the work rate achieved at peak exercise (WRpeak).
RESULTS: Predictive regression equations with submaximal VO2 at the VAT and with OUES, when combined with age and body fat percentage, explained >89% of the variance in VO2peak (optimism-adjusted R2 = 0.895 and 0.938). Predictive capacity increased when both VO2 at the VAT and OUES were combined in a predictive regression equation, together with age, body fat percentage, and clinically active disease (optimism-adjusted R2 = 0.951). Steep ramp test WRpeak explained 89% of the variance in VO2peak (optimism-adjusted R2 = 0.892).
CONCLUSION: The highly predictive equations developed in this study support the use of the submaximal CPET and the steep ramp test as alternatives for assessing VO2peak in patients with IBD in remission or with mild-to-moderate disease activity in clinical and research settings.

Patil, Pranoti R    Karad, INDIA.
Devi, Poovishnu T

Cureus [Cureus] 2026 Aug 29; Vol. 18 (8), pp. e115400. Date of Electronic Publication: 2026 Aug

Headings by Dr Older

Background Patients undergoing coronary artery bypass grafting (CABG) commonly experience reduced lower-limb strength, impaired balance, decreased functional mobility, and autonomic dysfunction during the postoperative period. These impairments may increase fall risk and limit daily activities. The Otago Exercise Program (OEP) is an evidence-based exercise intervention designed to improve lower-limb strength, balance, and functional performance, while resonance frequency breathing (RFB) has been shown to enhance cardiac autonomic regulation and heart rate variability (HRV). Although both interventions have demonstrated individual benefits, evidence regarding their combined application in phase II cardiac rehabilitation following CABG remains limited. Therefore, this study aimed to evaluate the effects of a combined OEP and RFB intervention on balance, lower-limb strength, functional mobility, and cardiac autonomic function in post-CABG patients.
Objective To evaluate the effects of a combined OEP and RFB intervention on balance, lower-limb strength, functional mobility, and cardiac autonomic regulation as evaluated via HRV in patients undergoing phase II cardiac rehabilitation following CABG.
Materials and methods A single-group pre-test and post-test experimental study was conducted among 40 post-CABG patients aged 40 to 60 years. The eight-week intervention combined supervised OEP multi-component exercises three times per week with daily home-based RFB paced precisely at six breaths per minute for 15 to 20 minutes. Lower extremity functional strength was evaluated by the 30-Second Chair Stand Test, and dynamic mobility was monitored with the Timed Up and Go (TUG) test. Static postural stability was evaluated using the Four-Stage Balance Test. Cardiac autonomic regulation was evaluated using short-term five-minute electrocardiographic (ECG) time-domain metrics, specifically tracked through the mean R-R interval and the root mean square of successive differences (RMSSD).
Results Improvements were observed following the intervention. The TUG test results improved from 17.95 ± 2.86 seconds to 14.68 ± 2.93 seconds (p < 0.001), indicating improvement in functional mobility. The lower limb strength also improved. The 30-Second Chair Stand Test scores went up from 13.03 ± 1.83 to 15.78 ± 2.03 repetitions (p < 0.001). We also saw improvements in balance, tandem stance, and single-leg stance (p < 0.0001). Autonomic function also improved, with an increase in RMSSD from 18.03 ± 2.59 ms to 21.96 ± 2.59 ms (p < 0.001); these findings suggest improved parasympathetic activity.
Conclusions The combined OEP and RFB intervention may support physical function, balance, functional mobility, and autonomic regulation in patients undergoing phase II cardiac rehabilitation after CABG surgery. The intervention appeared to be safe and useful in a home-based rehabilitation setting and may be a helpful approach in cardiac rehabilitation. However, the absence of a control group and separate OEP and RFB groups limits the ability to determine their individual or combined effects. Future studies with appropriate control and separate intervention groups are needed to confirm these findings.