Author Archives: Paul Older

Heart failure-related elevation of carbohydrate antigen 125 identified by pre-operative cardiopulmonary exercise testing.

Davies, R G; Department of Anaesthesia University Hospital of Wales Cardiff UK.
Fiorini, F;Bailey, D M

Anaesthesia reports,2025 Aug 27

Heart failure is a major peri-operative risk factor associated with significant postoperative morbidity and mortality. Traditional biomarkers used in heart failure management include natriuretic peptides. Carbohydrate antigen 125 biomarker is well known to be elevated in ovarian cancer but can also be elevated in heart failure, particularly right-sided heart failure and heart failure with preserved ejection fraction. We report the management of a 71-year-old woman with a presumed diagnosis of ovarian cancer based on imaging and an elevated carbohydrate antigen 125, who underwent cardiopulmonary exercise testing as part of the pre-operative assessment. Exercise testing, despite being sub-maximal, identified significant but asymptomatic heart failure. Surgery was deferred and cardiology-led optimisation resulted in normalisation of her carbohydrate antigen biomarker, refuting her ovarian cancer diagnosis and avoidance of a major intra-abdominal surgery. This case highlights the role of biomarkers, such as carbohydrate antigen 125, in heart failure treatment and the use of exercise testing in heart failure diagnosis and management. Cardiopulmonary exercise testing facilitated the identification of hidden comorbidities leading to better pre-operative risk stratification, optimisation and collaborative decision making.

Are counter movement jump and isometric mid-thigh pull tests reliable, valid, and sensitive measurement instruments when performed after maximal cardiopulmonary exercise testing? A sex-based analysis in elite athletes.

Pojskić, Hari; Department of Sports Science, Linnaeus University, Kalmar, Sweden.
Schiller, Jesper;Pagels, Peter;Ragnarsson, Thony; et al
Frontiers in physiology,2025 Sep 03
Both the countermovement jump (CMJ) and the isometric mid-thigh pull (IMTP) are frequently used performance tests to monitor neuromuscular fatigue and recovery after exhaustive physical activities. However, to date, neither the reliability nor the validity of the CMJ and IMTP performed after the cardiopulmonary exercise testing (CPET) has been studied. Thus, this study primarily aimed to investigate the intrasession relative and absolute reliability of the CMJ and IMTP when performed after the CPET. Second, the study aimed to examine the discriminative validity of the CMJ and IMTP performed after the CPET by differentiating between elite male and female athletes.
Twenty-eight female (26.8 ± 6.6 years) and seventeen male (23.8 ± 3.5 years) elite Swedish athletes voluntarily participated in the study. Protocols included anthropometric measurements, a cycle ergometer-based CPET (i.e., VO 2peak test), followed by three maximal test-retest CMJ and IMTP trials. Jump height, peak power, and relative peak power during CMJ and peak force and relative peak force during IMTP testing were analysed.
Results showed high relative reliability of the CMJ and IMTP in the total sample (ICC: 0.97 and 0.98) and separately in male (ICC: 0.88 and 0.98) and female (ICC: 0.98 and 0.93) athletes. The good absolute reliability of the CMJ and IMTP was evidenced by low within-subjects test-retest variability (CV WS %) and typical measurement error percentage, ranging between 5.7% and 6.5% and 6.3% and 8.9%, respectively. Both the CMJ and IMTP showed good test sensitivity, with the smallest worthwhile change exceeding the typical error. The CMJ’s jump height, relative peak power, and IMTP’s peak force showed a large discriminatory capacity to differentiate between male and female athletes (Cohen’s d = 3.92, 1.80 and 5.14, respectively). However, when the peak force was standardised relative to body mass and lean mass, the differences between sexes diminished. In conclusion, given that the CMJ and IMTP tests demonstrated high reliability and sensitivity following CPET, they could be confidently used as practical tools for monitoring neuromuscular fatigue and recovery, even after exhaustive cardiopulmonary exertion activities. Additionally, the demonstrated discriminative validity in differentiating between male and female athletes further supports their role in sex-specific performance profiling.

Optimizing the Interpretation of Cardiopulmonary Exercise Testing in Endurance Athletes: Precision Approach for Health and Performance.

Kowalski, Tomasz; Institute of Sport, National Research Institute, Warsaw 01-982, Poland.
Kasiak, Przemysław;Chomiuk, Tomasz;Mamcarz, Artur;
et al

Translational sports medicine,2025 Aug 20

The present review summarizes findings from the NOODLE (“predictioN mOdels fOr enDurance athLetEs”) study. The research aimed to refine variables obtained during cardiopulmonary exercise testing (CPET) in a large cohort of highly trained endurance athletes by adjusting general reference values and predictive equations to better reflect the unique physiological profiles of this population. Ventilatory efficiency, oxygen uptake efficiency slope, oxygen uptake efficiency plateau, and peak oxygen pulse were analyzed, as they were recently applied in various models concerning risk stratification and treatment optimization. As more people engage in endurance sports, tailored CPET assessments are crucial for accurate performance evaluation and health monitoring. By characterizing differences between general formulas and those suited for endurance athletes, we offered improved tools for optimizing training and ensuring athlete safety. The findings are in line with the existing trend of precision medicine that tailors diagnostics, treatments, and interventions to individual patients’ characteristics. Moreover, we review the recent advances from widely applied CPET-obtained indices, such as maximum oxygen uptake, maximum heart rate, and breathing reserve. We also gave the recommendation for a comprehensive CPET assessment based on the relationships between all of the variables.

Development and validation of clinical prediction models for cardiorespiratory fitness in atrial fibrillation patients following radiofrequency catheter ablation.

Zhao, Guiling;  Department of Cardiology, Xinhua Hospital , Shanghai, China.
Sun, Jian;Che, Qianji;Xu, Wenqing; et al

Frontiers in cardiovascular medicine,2025 Aug 29

  • Background: Assessment of cardiorespiratory fitness (CRF) is imperative in patients with atrial fibrillation (AF) who have had radiofrequency catheter ablation (RFCA). This study aimed to develop and validate CRF prediction models in this population.
  • Methods: 141 AF patients with RFCA were recruited. The cardiopulmonary exercise test was used to assess CRF with VO 2peak and METs max . Multidimensional predictors (demographics, serum biomarkers, cardiovascular parameters, and motor function parameters) were analyzed through Spearman correlation analysis and stepwise multivariate linear regression analysis. The internal validity of the prediction equation was tested by paired Student’s t -test, Pearson correlation analysis and Bland-Altman analysis.
  • Results: Sex, BMI, ln NT-proBNP, glucose (GLU), 6-minute walking distance (6MWD), and systolic blood pressure (SBP) were found to be significantly associated with CRF in this population. Multivariate linear regression generated the equations: VO 2peak = 35.080 – 0.286 * BMI – 1.927 * Sex – 1.090 * ln NT-proBNP + 0.011 * 6MWD – 0.039 * SBP – 0.512 * GLU, and METs max = 9.646 – 0.447 * Sex – 0.260 * ln NT-proBNP – 0.140 * GLU – 0.078 * BMI – 0.016 * SBP + 0.004 * 6MWD, (VO 2peak : adjusted R 2 = 0.506, and METs max : adjusted R 2 = 0.469, both P < 0.01). Pearson correlations between the predicted values and the measured values showed good validity (VO 2peak : r = 0.616, and METs max : r = 0.581, both P < 0.01). The Bland-Altman analysis showed that the predicted VO 2peak values were slightly lower than the measured values (mean difference = -0.13; 95% limits of agreement: -5.20 to 4.93), while the predicted METs max values were in close agreement with the measured values (mean difference = -0.00; 95% limits of agreement: -1.59 to 1.59).
  • Conclusion: Sex, BMI, NT-proBNP, glucose, 6MWD, and SBP are robust predictors of VO 2peak and METs max in AF population after RFCA. This study generates and internal validates the first multivariable CRF prediction models with easy-to use clinical paraments in AF patients after RFCA, thereby providing safe and effective alternatives to conventional CPX, which may help to optimize personalized patient management.

Recovery from COVID-19: a 12-month follow-up study on cardiorespiratory fitness and pulmonary function.

Goulart, Cássia da Luz; Federal University of Sao Carlos, UFSCar, Sao Carlos, Brazil.
Maldaner, Vinícius;Alves, Carla Cristina de Araújo;Milani, Mauricio;

Frontiers in cardiovascular medicine,2025 Aug 12

  • Introduction and Aim: Long COVID, characterized by persistent symptoms after acute infection, poses a major public health challenge. Understanding its long-term effects is crucial, particularly in relation to cardiorespiratory recovery. This study aimed to assess changes in cardiorespiratory fitness (CRF) and pulmonary function (PF) over 12 months following acute COVID-19, addressing a significant gap in current knowledge about the disease’s lasting impact.
  • Methods: This prospective cohort study included 29 individuals previously diagnosed with post-acute COVID-19. The baseline data were collected during the acute phase of infection . Participants underwent clinical evaluation, cardiopulmonary exercise testing (CPET), spirometry, and maximal inspiratory pressure (MIP) measurement at baseline and again after 12 months.
  • Results: After one-year, significant improvements were observed across several CPET parameters, including VE/MVV ratio (Cohen’s D = 0.66), peak oxygen uptake (VO 2 peak) in both absolute and relative terms (ml/min: d = 0.67; and ml/kg/min: d = 0.45), oxygen uptake efficiency slope (OUES; D = 0.47) and a reduction in VE/VCO 2 slope ( D = 0.80). Pulmonary function improved with increases in % predicted forced expiratory volume in 1 s (FEV 1 ; d = 0.67) and forced vital capacity (FVC; D = 0.67). MIP improved significantly ( D = 0.67), and the prevalence of inspiratory muscle weakness decreased from 20.7% at baseline to 3.5% at follow-up.
  • Conclusion: Despite the severity of their initial illness, patients demonstrated substantial recovery in CRF, PF, and inspiratory muscle strength over 12 months.

The Effects of Anakinra on Cardiorespiratory Fitness in Heart Failure Stratified by Age in Phase II Clinical Trials.

Hogwood AC; Robert M. Berne Cardiovascular Research Center, and Division of Cardiology, University of Virginia, Charlottesville, Virginia, United States.
Golino M; Moroni F; Canada JM; Del Buono MG; Arena R;Van Tassell B; Abbate A;

Journal of cardiovascular pharmacology [J Cardiovasc Pharmacol] 2025 Sep 09.
Date of Electronic Publication: 2025 Sep 09.

Competing Interests: Dr. Abbate has served as consultant to Kiniksa, Monte Rosa Therapeutics, and Novo Nordisk.
Cardiorespiratory fitness (CRF) in heart failure (HF) declines with age. Interleukin-1 (IL-1) is a pro-inflammatory cytokine involved in aging and HF. We aimed to determine the changes in CRF before and after treatment with anakinra, recombinant IL-1 receptor antagonist, in patients with HF stratified according to age below and above 60 years in phase II clinical trials. We analyzed data from 73 patients (37 [51%] female), 49 (67%) patients ˂60 years and 24 (33%) ≥60 years. All patients received anakinra 100 mg subcutaneously daily for a median of 4 (interquartile range from 2 to 12) weeks. We measured peak oxygen consumption (VO2peak) and high-sensitivity C-reactive protein (hsCRP). When compared with older patients, younger patients had higher baseline peak VO2 (15.2 [12.4-17.7] vs. 12.4 [10.3-14.3] mL·kg-1·min-1, p=0.001), yet no significant differences in hsCRP (6.6 [3.6-16.6] vs. 5.2 [2.7-11.2] mg/L, p=0.18). In both groups, anakinra decreased hsCRP (&lt;60 years: -3.6 [-8.1 to -1.9] mg/L; p&lt;0.001; ≥60 years: -2.7 [-9.0 to -1.4] mg/L; p&lt;0.001) and increased peak VO2peak (&lt;60 years: +0.5 [-0.9 – 2.5] mL·kg-1·min-1; p=0.036; ≥60 years: +1.1 [0.2 – 2.3] mL·kg-1·min-1; p&lt;0.001). No significant differences in changes across time were observed between the age groups. Older patients with HF have a greater baseline impairment in CRF compared to younger patients despite similar levels of systemic inflammation, and they appear to have a similar improvement in CRF following treatment with anakinra. The lack of an active control group (placebo) is a significant limitation and additional studies are needed to validate and expand these findings assessing clinical outcomes.

Exploring the limits of exercise capacity in adults with type II diabetes.

Michielsen M; Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
Bekhuis Y; Claes J; Decorte E; De Wilde C; Gojevic T; Costalunga L; Amyay S; Lazarou V; Daraki D; Kounalaki E; Chatzinikolaou P;Goetschalckx K;
Hansen D;Claessen G;Diepenbeek, Belgium.; De Craemer M; Cornelissen V;

PloS one [PLoS One] 2025 Sep 09; Vol. 20 (9), pp. e0331737.
Date of Electronic Publication: 2025 Sep 09 (Print Publication: 2025).

Objective: This study investigates the mechanisms behind exercise capacity in adults with type 2 diabetes mellitus (T2DM), focusing on central and peripheral components, as described by the Fick equation.
Methods: A cross-sectional study of 141 adults with T2DM was conducted, using cardiopulmonary exercise testing, near-infrared spectroscopy (NIRS) and exercise echocardiography. Participants with sufficient-quality NIRS data were stratified into tertiles based on percentage predicted VO₂peak. Group comparisons and stepwise regression were used to examine the contributions of central and peripheral components to VO₂peak.
Results: Sixty-seven participants had insufficient quality NIRS data. Those with lower-quality data were more likely to be female (p &lt; 0.001) and had a lower exercise capacity (p &lt; 0.001). Among participants with good-quality NIRS data, those in the lowest fitness tertile were older (p &lt; 0.01), had a longer diabetes duration (p = 0.04), lower eGFR (p &lt; 0.001) and more frequent use of beta-blockers (p = 0.02) and diuretics (p = 0.04). Significant differences were observed in peak cardiac output (p &lt; 0.001) and NIRS-derived parameters across fitness groups. Multivariate regression identified cardiac output as the strongest predictor of VO₂peak, while peripheral oxygen extraction did not improve model performance.
Conclusion: Cardiac output is the primary determinant of exercise capacity in adults with T2DM. This suggests that muscle perfusion may be the main limiting factor in relatively fit individuals with T2DM. However, cardiac output and local muscle perfusion are not directly equivalent, as mechanical factors, such as intramuscular pressure during high-intensity exercise, may prevent maximal perfusion.

Breathlessness abnormality is best assessed at peak exercise during incremental cardiopulmonary cycle exercise testing.

Ekström M; Lund University, Faculty of Medicine, Lund, Sweden  Quebec canada
Li PZ; Bourbeau J; Tan WC; Jensen D;

Chest [Chest] 2025 Sep 10.
Date of Electronic Publication: 2025 Sep 10.

Background: Breathlessness on exertion is a common, distressing and limiting symptom that can be quantified on incremental cardiopulmonary exercise testing (CPET) using normative reference equations.
Research Question: Is the breathlessness abnormality best uncovered and assessed at symptom limitation (peak exercise) compared with submaximal exercise intensities?
Study Design and Methods: Analysis of people aged ≥40 years undergoing symptom-limited incremental cycle CPET in the Canadian Cohort Obstructive Lung Disease (CanCOLD) study. Each Borg 0-10 scale breathlessness intensity rating during CPET was converted to its probability of being normal (P norm ), in relation to power output (W), rate of oxygen uptake (V’O 2 ) and minute ventilation (V’ E ) using normative reference equations. Abnormally high exertional breathlessness (abnormal breathlessness) was defined as a P norm &lt;0.05.
Results: Of 1,161 participants (42% women), abnormally high breathlessness was present in 22%, 23% and 16% in relation to W, V’O 2 and V’ E at peak exercise. Among those with abnormal breathlessness at peak exercise, 55-60% had normal breathlessness across all submaximal exercise intensities. Among those with normal breathlessness at peak exercise, 93-97% were normal across all serial breathlessness ratings throughout the CPET (interclass correlation coefficients=0.93-0.95). Findings were similar in people with or without chronic airflow limitation, and in people who did or did not reach maximal exertion at the end (symptom limitation) of the CPET.
Interpretation: Abnormal breathlessness is uncovered and should be assessed at peak exercise during symptom-limited incremental CPET. These findings inform symptom assessment in research and clinical practice.

Wave intensity analysis with exercise identifies impairments in pulmonary hypertension.

Lechuga CG;  Department of Biomedical Engineering, University of California, Irvine, Irvine, CA.
Raza F; Colebank MJ; Korcarz CE;Eickhoff JC; Chesler NC;

American journal of physiology. Heart and circulatory physiology [Am J Physiol Heart Circ Physiol] 2025 Sep 12.
Date of Electronic Publication: 2025 Sep 12.

Wave intensity analysis provides a novel approach to understanding the dynamic interactions between the right ventricle and pulmonary vasculature, particularly in pulmonary hypertension, a condition characterized by elevated pulmonary arterial pressures and vascular remodeling. This prospective study used wave intensity analysis to evaluate right ventricular and pulmonary vascular mechanics in 22 participants with pulmonary hypertension (including pre-capillary, isolated post-capillary, and combined pre-/post-capillary pulmonary hypertension), and 3 without pulmonary hypertension. Forward and backward compression and decompression waves were quantified at rest and during incremental exercise (25, 50, 75 watts). Relationships between metrics of wave intensity analysis, hemodynamics, right ventricular function, and oxygen consumption were analyzed using linear mixed-effects modeling. Wave intensity patterns highlighting vessel-specific pulmonary vascular and right ventricular pathobiology were observed in different phenotypes. Pre-capillary pulmonary hypertension exhibited highest forward compression waves, which correlated with right ventricular contractility (p&lt;0.01). Backward compression waves correlated strongly with characteristic impedance (p=0.002) in combined pre-/post-capillary pulmonary hypertension and inversely with pulmonary arterial compliance (p=0.003) in pre-capillary pulmonary hypertension. The ratio of backward to forward compression (systolic) waves decreased in isolated post-capillary pulmonary hypertension during exercise (p&lt;0.001), suggesting right ventricular reserve capacity that improves vascular-ventricular coupling. Wave intensity metrics demonstrated strong correlations with oxygen consumption in participants without pulmonary hypertension, indicating sensitivity to exercise-induced changes in cardiopulmonary status. Wave intensity analysis with exercise suggests vessel-specific pulmonary vascular and right ventricular characteristics unique to pulmonary hypertension phenotypes. These findings highlight wave intensity analysis as a promising tool for advancing understanding of cardiopulmonary pathobiology in pulmonary hypertension.