Fakhri S; Boston University Medical Center, Boston, Massachusetts, USA.
Campedelli L; Risbano MG

European Journal of Clinical Investigation. 55(2):e14343, 2025 Feb.

BACKGROUND: Preload insufficiency is an underrecognized cause of exercise
intolerance identified during invasive cardiopulmonary exercise testing,
and defined hemodynamically by decreased biatrial filling pressures,
cardiac output, and oxygen consumption (VO2) at peak effort. Patients with
preload insufficiency, however, typically present with symptoms of dyspnea
on exertion, and/or exercise intolerance at submaximal efforts,
particularly when performing activities of daily living. The
cardiopulmonary hemodynamics and physiology at submaximal work levels of
preload insufficiency have not been previously investigated. We
hypothesized that preload insufficiency hemodynamics exist along a
continuum, with submaximal exercise values reflecting peak exercise
cardiopulmonary hemodynamics.
METHODS: We compared submaximal cardiopulmonary hemodynamics, measured at
anaerobic threshold, between preload insufficiency patients and
age-matched controls referred for dyspnea but with normal exercise
responses.
RESULTS: Our study included 66 patients: 41 with preload insufficiency
and 25 controls. Preload insufficiency patients exhibit significantly
reduced VO2, watts, and METS at submaximal levels compared to controls,
alongside earlier anaerobic threshold achievement and similar heart rates
at anaerobic threshold.
CONCLUSIONS: These findings underscore the profound impact of preload
insufficiency on submaximal exercise capacity, emphasizing the importance
of its recognition and management. This insight sets the stage for further
investigations into interventions targeting preload insufficiency at
submaximal exercise levels to enhance both exercise performance and
quality of life.

Nilsson H; Linkoping University, Linkoping,Sweden
Bellander C; Carlen A; Nylander E; Hedman K; Tamas E

Open Heart. 12(1), 2025 Jan 21.
VI 1

AIMS: Exercise testing remains underused in patients with aortic stenosis
(AS), partly due to concerns about an exercise-induced drop in systolic
blood pressure (SBP). We aimed to study the SBP response to exercise in
patients with severe symptomatic AS prior to surgery and 1 year
postoperatively.

METHODS: Patients scheduled for aortic valve replacement due to severe
symptomatic AS were enrolled at a single centre in a prospective
observational cohort study. Maximal cardiopulmonary exercise testing
(CPET) was performed on a cycle ergometer at baseline and 1 year
postoperatively, using standard termination criteria. The SBP response was
categorised according to the last measurements of SBP during exercise, in
relation to workload (the SBP/watt-slope) as ‘normal’ (>0.25 mm Hg/watt),
‘flat’ (0-0.25 mm Hg/watt) or ‘drop’ (<0 mm Hg/watt).

RESULTS: 45 patients (28 male, 66+/-9 years, left ventricular ejection
fraction 59%+/-5%, aortic jet velocity 4.6+/-0.5 m/s) were included, with
pairwise comparison available in 31 cases. There were no adverse events.
Preoperatively, 4/45 patients were categorised as ‘drop’, 23 as ‘flat’ and
18 as ‘normal’. There was a change in the distribution of categories from
preoperative to postoperative measurements (43% ‘normal’ vs 74% ‘normal’,
p=0.0046). Maximal SBP and workload-indexed SBP were higher
postoperatively than preoperatively (203+/-26 vs 182+/-28 mm Hg, p<0.001
and 0.43+/-0.14 vs 0.29+/-0.15 mm Hg/watt, p<0.001).

CONCLUSION: As a drop in SBP was infrequent (<10%) in patients with
severe symptomatic AS and no adverse events occurred, our results indicate
that CPET may be performed under careful monitoring in AS patients.
Postoperatively, the SBP reaction improved, with no patient having a drop
in SBP.

• Kaikkonen, Piia; UKK Institute, Kaupinpuistonkatu 1, 33500, Tampere, Finland
  Pasanen, Kati; Parkkari, Jari;Mustakoski, Iida; Vasankari, Tommi; Leppänen, Mari

  European Journal of Applied Physiology (EUR J APPL PHYSIOL), Jan2025; 125(1): 71-79. (9p)

  No abstract available

• Engel, Luisa; Witten/Herdecke University, Faculty of Health/School of Medicine, Witten, Germany
  Strassmann, Stephan; Merten, Michaela; Schaefer, Simone; Färber, Johanna;Windisch, Wolfram; Karagiannidis, Christian

  Respiration (RESPIRATION), Jan2025; 104(1): 15-25. (11p)

  Introduction: Survivors of severe COVID-19 face complex challenges and a high degree of pulmonary sequelae. Therefore, we aim to describe their ongoing health burden.
  Methods: In this single-center prospective cohort study, COVID-19 ICU survivors were invited 3 and 6 months after ICU discharge. We examined pulmonary function with pulmonary function tests (PFT) and cardiopulmonary exercise testing (CPET), and we established health-related quality of life (HRQL) and health status (HS) with the EuroQol five-dimension five-level (EQ-5D-5L), the short-form health survey 12 (SF-12), and the modified British Medical Research Council dyspnea scale (mMRC) questionnaires.
  Results: Out of the 53 individuals screened, 23 participated in this study. Throughout both assessment points, participants maintained PFT results within range, apart from a decline in the transfer factor of the lung for carbon monoxide (TLCO). CPET showed improved fitness but persistent ventilatory deficiencies, indicated by altered dead space ventilation (VD/VT) and elevated arterial-alveoli gradient for oxygen (AaDO2). HRQL and HS remained compromised, with both physical (PCS) and mental component summary (MCS) scores significantly lower than the standardized norm population scores. Also, there was a rise in the prevalence of issues related to mobility, pain/discomfort, and anxiety/depression, and an increase in reported dyspnea.
  Conclusion: These results enhance our comprehension of the complex difficulties faced by COVID-19 ICU survivors. Six months post-discharge, CPET revealed the presence of ventilatory insufficiencies. Additionally, there was a decline in HRQL and HS, notably affected by mental health concerns and an increase in the level of dyspnea.

Peled K; Pediatric Cardiology unit, Padeh Medical Center, Poriya, Israel.; Pediatric Department, E. Wolfson Medical Center, Holon, Israel.
Kodesh E; Zucker-Toledano M; Bar-Yoseph R; Borik-Chiger S; Mainzer G;

Pediatric obesity [Pediatr Obes] 2025 Jan 06, pp. e13201.
Date of Electronic Publication: 2025 Jan 06.

Background: Peak oxygen uptake (VO ₂ ) is considered the most important indicator of aerobic exercise capacity during cardiopulmonary exercise testing (CPET). However, its accuracy is compromised when maximal effort is not achieved. In such cases, submaximal parameters can serve as surrogates for assessing exercise performance.
Objectives: To compare the differences in maximal and submaximal exercise parameters between children with obesity and normal weight.
Methods: A prospective study evaluating CPET using a treadmill completed by children with and without obesity.
Results: A total of 153 children (50.9% females) were divided into two groups: obese (n = 87) and non-obese (n = 66). Children with obesity achieved lower exercise capacity (peakVO ₂ of 68% ± 16% vs. 89% ± 15%; p < 0.0001) with fewer achieving maximal effort (26.4% vs. 78.7%, respectively). VO ₂ -derived submaximal parameters showed a significantly lower oxygen uptake efficiency slope per body weight (OUES/kg) (30.5 ± 6.1 vs. 39.0 ± 9.5; p < 0.0001) and lower VO ₂ at ventilatory threshold (VO ₂ @AT) (21.2 ± 4.6 vs. 26.4 ± 5.3, p = 0.0001) in the obese group, with no significant differences in the CO ₂ -derived parameters.
Conclusions: Maximal exercise data in children with obesity is frequently unavailable due to failure to achieve maximal effort. Submaximal parameters, such as OUES and VO ₂ @AT, may be useful substitute options for assessing the health and functional level of this population.

Hansen K; Department of Cardiology, Boston Children’s Hospital, Boston, MA, USA.;
Curran T; Reynolds L; Cameron C; Pymm J; O’Neill JA; Losi R; Sherman C;Ackermans E; Yin S; Singh T; Alexander ME; Gauvreau K; Gauthier N;

International journal of cardiology. Congenital heart disease [Int J Cardiol Congenit Heart Dis] 2024 Aug 27; Vol. 18, pp. 100540.
Date of Electronic Publication: 2024 Aug 27 (Print Publication: 2024).

Background: Change in the oxygen consumption (VO ₂ ) at the ventilatory anaerobic threshold (VAT) is an important outcome in research studies of children with congenital heart disease (CHD). The range of values reported by different raters for any given VAT is needed to contextualize a change in VAT in intervention studies.
Methods: Sixty maximal cardiopulmonary exercise tests (CPET) for CHD patients 8-21 years old were independently reviewed by six exercise physiologists and four pediatric cardiologists. For each of the unique rater pairs for the 60 CPETs, the absolute difference in VAT was calculated and displayed on a histogram to demonstrate the distribution of inter-rater variability. This method was repeated for subgroups of test modality (cycle/treadmill), patient factors (diagnoses, exercise capacity), and rater factors (cardiologist/physiologist, years of experience).
Results: Rater agreement was good with an intraclass correlation coefficient of 0.79-0.91 but the distribution of differences was broad. The median difference was 2.7 % predicted peak VO ₂ (60 mL/min, 1.0 mL/kg/min), the 75th percentile was 6.4 % (140 mL/min, 2.5 mL/kg/min), and the 95th percentile was 16.3 % (421 mL/min, 6.5 mL/kg/min). Distributions were similar for CPET modality and years of rater experience, but differed for other factors.
Conclusions: The baseline distribution of reported VAT is relatively broad, varied by units, and was not explained by differences in rater experience or test modality, but varies by patient factors. When evaluating clinical relevance, a change in the VO ₂ at VAT in response to an intervention of <6.5 % predicted falls within the majority (75th percentile) of expected variability and should be interpreted with caution.

FitzMaurice TS; Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool, UK.;
Hawkes S; Liao Y; Cullington D; Bryan A; Redfern J; Ashrafi R;

International journal of cardiology. Congenital heart disease [Int J Cardiol Congenit Heart Dis] 2024 Sep 29; Vol. 18, pp. 100546.
Date of Electronic Publication: 2024 Sep 29 (Print Publication: 2024).

Introduction: Assessment of exercise capacity by cardiopulmonary exercise testing (CPET) in adults with congenital heart disease (CHD) is important for prognostication and preoperative assessment. Peak oxygen uptake (PVO ₂ ) is used commonly, but can be challenging due to the difficulties of undertaking maximal CPET testing in this population. We explored whether oxygen uptake efficiency slope (OUES) at ventilatory anaerobic threshold (VAT), the point during CPET at which OUES becomes strongly correlated with PVO ₂ , and is more reliably available from submaximal CPET, can predict PVO ₂ in adults with CHD.
Methods: We assessed consecutive individuals who completed maximal CPET at our cardiorespiratory centre, as part of routine service review, between March 2019 and August 2021, recording data such as PVO ₂ , VAT and OUES at various proportions of a maximal test (75 %, 90 %, 100 %, and VAT). We employed linear regression modelling to analyse the association between PVO ₂ and OUES at VAT, and subsequently create an equation to predict PVO ₂ from OUES at VAT. Parametric data are presented using Pearson’s correlation coefficient and non-parametric data using Spearman’s rho.
Results: We analysed 391 individuals (177 female, age 32 ± 11 years). Mean ± SD PVO ₂ was 23.3 ± 6.86 ml/min/kg or 1724 ± 540 ml/min, peak VE 86.7 ± 25.4 l/min. The point of VAT as a percentage of PVO ₂ achieved was 66.5 ± 9.4 %, and VAT as a percentage of predicted PVO ₂ 46.9 ± 11.4 %. PVO ₂ was correlated with OUES at 100 % (R = 0.91, P < .001), 90 % (R = 0.91, P < .001), 75 % (R = 0.89, P < .001) of maximum, and VAT (R = 0.83, P < .001). PVO ₂ (ml/min) could be predicted by: (OUES at VAT)∗685.245 + (BMI [kg/m ² ])∗5.045 + (FEV ₁ [l])∗223.620 – 153.205 .
Conclusions: OUES at VAT can be used to calculate PVO ₂ . To our knowledge, this is the first equation using OUES at VAT to predict PVO ₂ in adults with CHD. In a population who may find maximal CPET difficult, this may be a useful submaximal measurement of cardiovascular fitness, and to calculate PVO ₂ , which is commonly used in guideline-based decision making in CHD.

Stiefel M; Department of Cardiology, University Heart Center, University Hospital Zurich, 8091 Zurich, Switzerland.
Brito da Silva H; Schmied CM; NiederseerD;

Journal of cardiovascular development and disease [J Cardiovasc Dev Dis] 2024 Nov 27; Vol. 11 (12).
Date of Electronic Publication: 2024 Nov 27.

Introduction: Balancing the well-documented benefits of regular exercise, particularly its positive impact on cardiovascular risk factors like hypertension, with the potential risks for patients with aortic aneurysms presents a significant challenge. This narrative review aims to summarize the current evidence and guidelines to assist clinicians in making informed exercise and sports recommendations for patients with aortic aneurysms or post-aortic repair.
Methods: Nine clinical trials on the effect of exercise on abdominal aortic aneurysms (AAAs) were identified, including one study on cardiopulmonary exercise testing (CPET) in AAA patients. As no clinical trials on exercise in thoracic aortic aneurysms (TAAs) were found, we extrapolated data from other studies on exercise in aortic diseases, including data from patients who have had an aortic dissection, as well as three studies on cardiac rehabilitation (CR) and one study on CPET after proximal aortic repair. Review articles and guidelines were also incorporated to ensure a comprehensive overview of the topic.
Results: Currently, no clear correlation exists between intense sports activities and the development of aortic aneurysms or dissections.
Conclusions: Light to moderate physical activity appears safe and beneficial for patients with aortic aneurysms and post-aortic repair. Given the lack of evidence linking athletic activity to aortic complications, caution is warranted in restricting such activities for athletes, underscoring the importance of shared decision-making. Regular follow-up and optimal management of cardiovascular risk factors are essential.

Ahn HB; Department of Cardiology, Seongnam, Gyeonggi-do, Republic of Korea.;
Park J; Choi HJ; Choi HM; Hwang IC; Yoon YE; Cho GY;

American journal of preventive cardiology [Am J Prev Cardiol] 2024 Dec 06; Vol. 21, pp. 100913.
Date of Electronic Publication: 2024 Dec 06 (Print Publication: 2025).

Background: Given the high prevalence of stage A or B heart failure (HF), comprehensive screening for new-onset HF is cost-prohibitive. Therefore, further risk stratification is warranted to identify at-risk patients. This study aimed to evaluate the prognostic utility of cardiopulmonary exercise test (CPET) with bicycle stress echocardiography (BSE) in patients with stage A or B HF.
Methods: Among 687 consecutive patients who underwent CPET-BSE, 410 with stage A or B HF were analyzed. The association between the CPET-BSE parameters and adverse cardiac events (hospitalization for HF or cardiac-related death) was analyzed using the Cox proportional hazard model under univariate and multivariate analyses.
Results: After a median 9 years of follow-up, 47 (11.5 %) of the 410 patients had events. In the univariable analysis, age, diuretics, BUN, creatinine, peak oxygen uptake (VO2), ventilatory efficiency (VE/VCO ₂ ), time to VT and peak exercise, left atrial volume index, rest and exercise E/e’, and tricuspid regurgitation velocity demonstrated significant parameters. In multivariate analysis, VE/VCO ₂ (hazard ratio [HR] 1.205, 95 % CI 1.095-1.327) and VO ₂ at peak exercise (HR 1.164, 95 % CI 1.022-1.325), time to VT (HR 0.993, 95 % CI 0.989-0.997), and exercise E/e’ (HR 1.582, 95 % CI 1.199-2.087) were only independent predictors for events.
Conclusions: In patients with stage A or B HF, four parameters of CPET-BSE were good predictors of future development of HF or cardiac death. If patients are unable to perform complete exercise, the time to VT may serve as a sufficiently predictive parameter for clinical events.

Santana EJ; Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, and other USA Universities
Cauwenberghs N; Celestin BE; Kuznetsova T; Gardner C; Arena R; Kaminsky LA; Harber MP; Ashley E;Christle JW; Myers J; Haddad F

Frontiers in cardiovascular medicine [Front Cardiovasc Med] 2024 Dec 10; Vol. 11, pp. 1393363.
Date of Electronic Publication: 2024 Dec 10 (Print Publication: 2024).

Background: Indexing peak oxygen uptake (VO ₂ peak) to total body mass can underestimate cardiorespiratory fitness (CRF) in women, older adults, and individuals with obesity. The primary objective of this multicenter study was to derive and validate a body size-independent scaling metric for VO ₂ peak. This metric was termed exercise body mass (EBM).
Method: In a cohort of apparently healthy individuals from the Fitness Registry and the Importance of Exercise National Database, we derived EBM using multivariable log-normal regression analysis. Subsequently, we developed a novel workload (WL) equation based on speed (Sp), fractional grade (fGr), and heart rate reserve (HRR). The generalized equation for VO ₂ peak can be expressed as VO ₂ peak = Cst × EBM × WL, where Cst is a constant representing the VO ₂ peak equivalent of one metabolic equivalent of task. This generalized equation was externally validated using the Stanford exercise testing (SET) dataset.
Results: A total of 5,618 apparently healthy individuals with a respiratory exchange ratio >1.0 (57% men, mean age 44 ± 13 years) were included. The EBM was expressed as Mass (kg) ^0.63  × Height (m) ^0.53  × 1.16 (if a man) × exp (-0.39 × 10 ^-4  × age ² ), which was also approximated using simple sex-specific additive equations. Unlike total body mass, EBM provided body size-independent scaling across both sexes and WL categories. The generalized VO ₂ peak equation was expressed as 11 × EBM × [2 + Sp (in mph) × (1.06 + 5.22 × fGr) + 0.019 × HRR] and had an R ² of 0.83, p  < 0.001. This generalized equation mitigated bias in VO ₂ peak estimations across age, sex, and body mass index subgroups and was validated in the SET registry, achieving an R ² of 0.84 ( p  < 0.001).
Conclusions: We derived a generalized equation for measuring VO ₂ peak during treadmill exercise testing using a novel body size-independent scaling metric. This approach significantly reduced biases in CRF estimates across age, sex, and body composition.