Cardiopulmonary Exercise Testing Parameters Research Articles

Prognostic value of cardiopulmonary exercise test in patients with acute myocardial infarction after percutaneous coronary intervention

To determine the independent risk factors of cardiopulmonary exercise test (CPET) parameters related to adverse prognostic events within 5 years in patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI), and establish a prediction model for the occurrence of adverse events within 5 years to provide a reference for cardiac rehabilitation training. From August 2015 to December 2021, patients who underwent PCI for AMI and completed CPET within 1–2 weeks after surgery before discharge from the Department of Cardiovascular Medicine of Zhengzhou Central Hospital Affiliated to Zhengzhou University, Henan Provincial Hospital of Traditional Chinese Medicine, and Anyang District Hospital were selected as participants. Univariate and multivariate analyses were used to screen for independent risk factors associated with 5-year adverse events. Feature importance was interpreted using SHapley Additive exPlanations (SHAP), and a logistic regression model was established for prediction. A receiver operating characteristic (ROC) curve was constructed to evaluate the performance of the prediction model. Calibration was assessed by the Hosmer–Lemeshow test and the calibration curve. In total, 375 patients met the inclusion criteria. Based on whether adverse events occurred during the 5-year follow-up period, the patients were divided into two groups: the event group (n = 53) and the non-event group (n = 322). Peak oxygen uptake (peakVO2), carbon dioxide ventilation equivalent slope (VE/VCO2slop), and peak end-tidal carbon dioxide partial pressure (PETCO2) were three independent risk factors for re-acute myocardial infarction (re-AMI), heart failure (HF), and even death after PCI for AMI (P < 0.05). The SHAP plots demonstrated that the significant contributors to model performance were related to peakVO2, VE/VCO2slop, and PETCO2. The risk of adverse events was significantly reduced when the peakVO2 was ≥ 20 mL/kg/min and the VE/VCO2slop was < 33. The ROC curves of the three models were drawn, including the no-event and event groups, re-AMI group, and HF group, which performed well, with AUC of 0.894, 0.760, and 0.883, respectively. The Hosmer–Lemeshow test showed that the three models were a good fit (P > 0.05). The calibration curve of the three models was close to the ideal diagonal lines. CPET parameters can predict the prognosis of adverse events within 5 years after PCI in patients with AMI and provide a theoretical basis for cardiac rehabilitation training.

Combined Exercise and Mindset Training During a Pediatric Cardiac Fitness and Rehabilitation Program Benefits Youth with a Range of Congenital Heart Disease.

Pediatric cardiac fitness and rehabilitation programs vary widely in structure and content. The Cardiac Fitness Program (CFP) is built on traditional training pillars of aerobic, strength, and flexibility, and adds a fourth, training a positive mindset. This study assesses whether the systematic and comprehensive framework of the CFP results in broad benefits for a range of patients with congenital heart disease (CHD). Data from participants between 01/2017 and 12/2022 were analyzed. Pre- and post-CFP cardiopulmonary exercise test parameters, strength and flexibility metrics, and mindset survey results were compared overall, and by sex, age, diagnosis, and hemodynamic level. Of 62 participants (median age 15.5years, range 8 to 23, 50% female), 3% had simple, 37% complex, 24% single ventricle CHD, and 35% arrhythmia, cardiomyopathy, or transplant. Significant improvements were noted in aerobic fitness (mean 9 ± 15% increase in % predicted peak oxygen consumption, p < 0.001). Strength metrics significantly improved (each p < 0.001), as did flexibility (p < 0.001). Patient-reported positive mindset scores did not improve significantly (mean increase 1.8 ± 5.1, p = 0.10, n = 25), whereas parents reported significant improvements (5.9 ± 10.4, p = 0.02, n = 20). Improvements were not significantly different by sex, age, diagnosis, or hemodynamic level. Comprehensive training across four pillars of fitness yields significant improvements in aerobic fitness, strength, flexibility, and parent-reported mindset scores for pediatric CHD patients, regardless of patient characteristics, diagnosis type, or severity of hemodynamic limitation. Further study is warranted into optimal standardization of training and whether a comprehensive approach amplifies individual pillars to create more than the sum of its parts.

Effects of Positive Airway Pressure on Cardiorespiratory Fitness in Patients with Concomitant Obstructive Sleep Apnea and Cardiovascular Disease.

Background and Objectives: Obstructive sleep apnea (OSA) is common in cardiovascular disease (CVD), although positive airway pressure (PAP) treatment has not been demonstrated to improve the cardiovascular outcome. The objective of this study is to investigate the impact of adherence to PAP therapy on cardiopulmonary exercise testing (CPET) performance in patients with concomitant OSA and CVD. Materials and Methods: This preliminary study involved symptomatic OSA patients requiring PAP treatment who had CVD. All subjects underwent polysomnography, echocardiography, and CPET at baseline. After 6 to 12 months of PAP treatment, CPET performance was re-assessed. The changes in CPET parameters before and after PAP treatment were compared between patients who were adherent to PAP and patients who were not adherent to PAP. Results: A total of 16 OSA patients with an apnea-hypopnea index of 32.0 ± 23.4 were enrolled. Patients were classified into the adherent (n = 9) and non-adherent (n = 7) groups with regard to PAP adherence. After 6 to 12 months of PAP treatment, the PAP-adherent group showed a greater increase in peak VO2 than the PAP-non-adherent group, but the difference between the two groups was not significant (p = 0.581). The decrease in ventilatory equivalent for the carbon dioxide slope (VE/VCO2) was significantly greater in the PAP-adherent group compared to the PAP-non-adherent group (p = 0.030). Conclusions: Adherence to PAP therapy for OSA is associated with an improvement in the VE/VCO2 slope, as an index of the ventilatory response to exercise, in patients with CVD. Screening for sleep apnea in CVD patients may be warranted, and strategies to optimize adherence to PAP in these patients are beneficial. Further evidence is needed to elucidate whether CPET could be routinely used to monitor treatment responses of OSA to PAP therapy in patients with CVD.

A Summed Score From Cardiopulmonary Exercise Test Parameters Predicts 1-Year Mortality in Newly Diagnosed Interstitial Lung Disease.

Cardiopulmonary exercise testing (CPET) is a unique diagnostic tool that assesses the functional capacity of the heart, lungs, and peripheral oxidative system in an integrated manner. However, the clinical utility of CPET for evaluating interstitial lung disease (ILD) remains uncertain. The objective of this study was to determine the predictive value of CPET for mortality in subjects with ILD. We prospectively enrolled subjects with ILD who underwent CPET at a tertiary medical center in Taiwan and followed up their survival status for 12 months. Mortality prediction was based on comparing CPET parameters between subjects who survived and those who died. We further analyzed CPET parameters that showed significant differences using receiver operating characteristic curves to identify their optimal cutoff values. A total of 106 newly diagnosed subjects with ILD underwent CPET, and the 1-y mortality rate was 7.5%. Six CPET variables were found to be significant predictors of mortality: peak oxygen consumption, oxygen pulse, end-tidal partial pressure of carbon dioxide, heart rate recovery 1 min after CPET, minute ventilation to carbon dioxide output slope, and functional aerobic impairment. We calculated a summed score by adding the number of CPET variables that exceeded their cutoff values. Subjects with a summed score of 6 had a 1-y survival rate of only 25%, whereas subjects with scores of 0-5 had a survival rate of 98%. In conclusion, the summed score represents a useful tool for screening patients with ILD who can undergo a CPET to determine their prognosis.

Physical activity, sedentary time, and fitness parameters of cardiopulmonary exercise testing: a compositional data analysis among a population-based adult sample

Physical activity, sedentary time, and fitness parameters of cardiopulmonary exercise testing: a compositional data analysis among a population-based adult sample

#1555 The effects of different interdialytic intervals on cardiorespiratory fitness assessed with CPET in hemodialysis patients

Abstract Background and Aims Long interdialytic interval in thrice-weekly hemodialysis is associated with excess cardiovascular and all-cause mortality risk. Impaired cardiorespiratory fitness is a strong predictor of mortality in hemodialysis. This study investigated differences in cardiorespiratory fitness assessed with cardiopulmonary exercise testing (CPET) between the end of the 2-day and the 3-day interdialytic interval. Method A total of 28 hemodialysis patients, randomized in two different sequences of evaluation underwent CPET and spirometry examination at the end of the 2-day and the 3-day intervals. The primary outcome was the difference in oxygen uptake at peak exercise [VO2peak (ml/kg/min)] assessed with CPET. Volume status was assessed with interdialytic-weight-gain (IDWG), lung ultrasound, bioimpedance spectroscopy (BIS), and inferior vena cava measurements. A total of 14 age- and sex-matched controls were also evaluated. Results Hemodialysis patients at the end of both 2-day and 3-day intervals presented lower values in all major CPET parameters than controls. VO2peak (ml/kg/min) was significantly higher at the end of the 2-day than the 3-day interval (15.24 ± 4.18 vs 13.64 ± 2.76; p &amp;lt; 0.001); similar were the results for VO2peak (ml/min) (1188 ± 257 vs 1074 ± 224; p &amp;lt; 0.001) and VO2peak (%predicted) (58.9 ± 9.2 vs 52.3 ± 8.6; p &amp;lt; 0.001). Numerical but no statistically significant differences were detected in VO2-anaerobic-threshold(ml/kg/min) and VO2-anaerobic-threshold(ml/min) between the two time-points. Maximal work load (90.1 ± 23.2 vs 79.3 ± 25.1; p &amp;lt; 0.001), exercise duration, HR at peak exercise and oxygen pulse also showed lower values at the end of the 3-day interval. FEV1 levels were similar between the two evaluations. Generalized-linear-mixed-model analysis including IDWG as random covariate attenuated the observed differences in VO2peak (ml/kg/min). Changes in BIS-derived overhydration indexes were moderately correlated with changes of VO2peak (ml/kg/min). Conclusion The 3-day interval was associated with further impairment of VO2 at peak exercise. This effect was predominantly driven by excess fluid accumulation during the extra interdialytic day.

Pulmonary perfusion defects or residual vascular obstruction and persistent symptoms after pulmonary embolism: a systematic review and meta-analysis.

Up to 50% of pulmonary embolism (PE) patients have perfusion defects or residual vascular obstruction during follow-up despite adequate anticoagulant treatment, and a similar percentage experience chronic functional limitations and/or dyspnoea post-PE. We aimed to evaluate the association between pulmonary perfusion defects or residual vascular obstruction and functional recovery after PE. We performed a systematic review and meta-analysis including studies assessing both the presence of perfusion defects or residual vascular obstruction and functional recovery (i.e. persistent symptoms, quality of life, exercise endurance). An odds ratio was pooled for perfusion defects or residual vascular obstruction and persistent symptoms using a random-effect model. 12 studies were included totalling 1888 PE patients; at a median of 6 months after PE (range 2-72 months), 34% had perfusion defects or residual vascular obstruction and 37% reported persistent symptoms. Among patients with perfusion defects or residual vascular obstruction, 48% (95% CI 37-60%, I2=82%) remained symptomatic during follow-up, compared to 34% (95% CI 20-51%, I2=96%) of patients without such defects. Presence of perfusion defects or residual vascular obstruction was associated with persistent symptoms (OR 2.15, 95% CI 1.66-2.78; I2=0%, τ=0). Notably, there was no association between these defects and quality of life or cardiopulmonary exercise test parameters. While the odds of having persistent symptoms was higher in patients with perfusion defects or residual vascular obstruction after acute PE, a significant proportion of these patients reported no limitations. A possible causality between perfusion defects or residual vascular obstruction and residual functional limitation therefore remains to be proven.

Cardiopulmonary Exercise Testing Predicts Postoperative Morbidity after Major Abdominal Cancer Surgeries: A Prospective Observational Study

Background and Aim: Cardiopulmonary exercise testing (CPET) has been shown to predict outcomes after major surgery. However, CPET performance and risk thresholds may vary geographically due to different body composition, nutritional status, anaemia, etc. This study aimed to investigate the relationship between preoperative CPET variables and in-hospital morbidity after abdominal cancer surgeries. Methods: In this prospective observational study, 142 patients aged 18–70 years, American Society of Anesthesiologists Physical Status II–III, underwent CPET preoperatively within 7 days of planned surgery. Oxygen uptake (VO2), ventilatory equivalents for carbon dioxide, heart rate (HR) and oxygen pulse (VO2/HR) were measured at anaerobic threshold (AT) and peak exercise (PE). Morbidity was assessed using the postoperative morbidity survey (POMS) postoperatively on days 3, 5 and 7. Receiver operating characteristic (ROC) curves were constructed to assess the optimal cut-offs for various CPET parameters. A multivariate logistic regression model was applied to test the relationship between CPET and postoperative morbidity. Results: After excluding patients who met the exclusion criteria, data from 109 participants were available for analysis. Forty-two patients (39%) suffered some morbidity postoperatively. VO2@AT (univariate odds ratio (OR) 1.36 [1.11–1.67] P = 0.002), sex (0.40 [0.17–0.99] P = 0.04), HR@AT (0.91 [0.94–0.99] P = 0.01), VO2/HR@AT (2.00 [1.42–2.80] P &lt; 0.001) and VO2/HR@PE (2.04 [1.45–2.87] P &lt; 0.001] were associated with postoperative morbidity. The final multivariate regression model contained VO2@AT (multivariate OR 1.25 [1.00–1.56] P = 0.04) and VO2/HR@PE (1.89 [1.34–11.09] P = 0.001). ROC curves revealed the optimal cut-off for VO2@AT as 11.9 ml/kg/min and VO2/HR@PE at 6.1 ml/beat. Conclusion: CPET parameters of oxygen uptake at AT and oxygen pulse at PE can predict morbidity in patients undergoing major abdominal onco-surgeries.

THE EFFECTS OF DIFFERENT INTERDIALYTIC INTERVALS ON CARDIORESPIRATORY FITNESS ASSESSED WITH CARDIOPULMONARY EXERCISE TESTING IN HEMODIALYSIS PATIENTS

Objective: Long interdialytic interval in thrice-weekly hemodialysis is associated with excess cardiovascular and all-cause mortality risk. Impaired cardiorespiratory fitness is a strong predictor of mortality in hemodialysis. This study investigated differences in cardiorespiratory fitness assessed with cardiopulmonary exercise testing (CPET) between the end of the 2-day and the 3-day interdialytic interval. Design and method: A total of 28 hemodialysis patients, randomized in two different sequences of evaluation underwent CPET and spirometry examination at the end of the 2-day and the 3-day intervals. The primary outcome was the difference in oxygen uptake at peak exercise [VO2peak(ml/kg/min)] assessed with CPET. Volume status was assessed with interdialytic-weight-gain (IDWG), lung ultrasound, bioimpedance spectroscopy (BIS), and inferior vena cava measurements. A total of 14 age- and sex-matched controls were also evaluated. Results: Hemodialysis patients at the end of both 2-day and 3-day intervals presented lower values in all major CPET parameters than controls. VO2peak(ml/kg/min) was significantly higher at the end of the 2-day than the 3-day interval (15.24±4.18 vs 13.64±2.76;p&lt;0.001); similar were the results for VO2peak(ml/min) (1188±257 vs 1074±224;p&lt;0.001) and VO2peak(%predicted) (58.9±9.2 vs 52.3±8.6;p&lt;0.001). Numerical but no statistically significant differences were detected in VO2-anaerobic-threshold(ml/kg/min) and VO2-anaerobic-threshold(ml/min) between the two time-points. Maximal work load (90.1±23.2 vs 79.3±25.1;p&lt;0.001), exercise duration, HR at peak exercise and oxygen pulse also showed lower values at the end of the 3-day interval. FEV1 levels were similar between the two evaluations. Generalized-linear-mixed-model analysis including IDWG as random covariate attenuated the observed differences in VO2peak(ml/kg/min). Changes in BIS-derived overhydration indexes were moderately correlated with changes of VO2peak(ml/kg/min). Conclusions: The 3-day interval was associated with further impairment of VO2 at peak exercise. This effect was predominantly driven by excess fluid accumulation during the extra interdialytic day.

The association between O2-pulse slope ratio and functional severity of coronary stenosis: A combined cardiopulmonary exercise testing and quantitative flow ratio study

BackgroundThe role of cardiopulmonary exercise testing (CPET) parameters in evaluating the functional severity of coronary disease remains unclear. The aim of this study was to quantify the O2-pulse morphology and investigate its relevance in predicting the functional severity of coronary stenosis, using Murray law-based quantitative flow ratio (μQFR) as the reference. MethodsCPET and μQFR were analyzed in 138 patients with stable coronary artery disease (CAD). The O2-pulse morphology was quantified through calculating the O2-pulse slope ratio. The presence of O2-pulse plateau was defined according to the best cutoff value of O2-pulse slope ratio for predicting μQFR ≤ 0.8. ResultsThe optimal cutoff value of O2-pulse slope ratio for predicting μQFR ≤ 0.8 was 0.4, with area under the curve (AUC) of 0.632 (95 % CI: 0.505–0.759, p = 0.032). The total discordance rate between O2-pulse slope ratio and μQFR was 27.5 %, with 13 patients (9.4 %) being classified as mismatch (O2-pulse slope ratio > 0.4 and μQFR ≤ 0.8) and 25 patients being classified as reverse-mismatch (O2-pulse slope ratio ≤ 0.4 and μQFR > 0.8). Angiography-derived microvascular resistance was independently associated with mismatch (OR 0.07; 95 % CI: 0.01–0.38, p = 0.002) and reverse-mismatch (OR 9.76; 95 % CI: 1.47–64.82, p = 0.018). ConclusionOur findings demonstrate the potential of the CPET-derived O2-pulse slope ratio for assessing myocardial ischemia in stable CAD patients.

Cardiopulmonary exercise testing and the 2022 definition of pulmonary hypertension.

Parameters of cardiopulmonary exercise testing significantly discriminate between healthy subjects and patients with pulmonary hypertension (PH), also according to the new 2022 definition of pulmonary hypertension (mean pulmonary arterial pressure mPAP > 20 mmHg). The cut-offs indicating on PH were peakVO2 ≤ 16.7 mL/min/kg (Youden-Index YI = 0.79), petCO2@AT ≤ 34 mmHg (YI = 0.67), and VE/VCO2@AT ≤ 30 (YI = 0.76).

Cardiac magnetic resonance ventricular parameters correlate with cardiopulmonary fitness in patients with functional single ventricle.

Owing to advances in medical and surgical fields, patients with single ventricle (SV) have a greatly improved life expectancy. However, progressive functional deteriorationis observed over time, with a decrease in cardiopulmonary fitness. This study aimed to identify, in patients with SV, the association between cardiac magnetic resonance imaging (CMR) parameters and change in cardiopulmonary fitness assessed by cardiopulmonary exercise test (CPET), and if certain thresholds could anticipate a decline in aerobic fitness. Patients with an SV physiology were retrospectively screened from 2011 and 2021 in a single-centre observational study. We evaluated (1) the correlation between baseline CMR and CPET parameters,(2) the association between baseline CMR results and change in peak oxygen uptake (peak VO2), and (3) the cut-off values of end-diastolic and end-systolic volume index in patients with an impaired cardiopulmonary fitness (low peak VO2 and/or high VE/VCO2 slope). 32patients were included in the study. End-systolic volume index (r = 0.37,p = 0.03), end-diastolic volume index (r = 0.45,p = 0.01), and cardiac index (r = 0.46,p = 0.01) correlated with the VE/VCO2slope. End-systolic ventricular volume (r = -0.39,p = 0.01), end-diastolic ventricular volume (r = -0.38,p = 0.01), and cardiac output (r = -0.45,p < 0.01) inversely correlated with the peak VO2. In multivariate analysis, the cardiac index obtained from baseline CMR was inversely associated with the change in peak VO2(p < 0.01). An end-diastolic volume index > 101ml/m2 and an end-systolic volume index > 47ml/m2discriminated patients with impaired cardiopulmonary fitness. CMR parameters correlate with cardiopulmonary fitness in patients with SV and can therefore be useful for follow-up and therapeutic management of these patients.

Cardiopulmonary exercise testing complements both spirometry and nuclear imaging for assessing sarcoidosis stage and for monitoring disease activity.

Pulmonary sarcoidosis is a systemic disease that can confound established follow-up tools. Pulmonary function tests (PFTs) are recommended in initial and follow-up patient evaluations yet are imperfect predictors of disease progression. The cardiopulmonary exercise test (CPET) is another potentially useful monitoring tool, although previous studies report conflicting findings regarding which variables are altered by the disease. Nuclear imaging tests are also employed to assess inflammatory activity and may be predictive of functional deterioration. We asked whether PFTs or CPET are more diagnostic of disease stage, which subsets of functional variables are impacted by the disease, and how these relate to nuclear imaging signs of active inflammation. We collected retrospective data (spirometry, CPET, Gallium-67 scintigraphy, 18F-FDG PET/CT) from 48 patients and 10 controls. Disease severity was assessed following Scadding classification. First, we correlated individual PFTs and CPET parameters to Scadding stage and nuclear imaging data. Next, we performed Principal Component Analysis (PCA) on PFTs and CPET parameters, separated into respiratory, cardiovascular and metabolic subsets. Finally, we constructed multiple regression models to determine which variable subsets were the best predictors of Scadding stage and disease activity. The majority of PFTs and CPET single parameters were significantly correlated with patient stage, while only few correlated with disease activity. Nevertheless, multiple regression models were able to significantly relate PFTs and CPET to both disease stage and activity. Additionally, these analyses highlighted CPET cardiovascular parameters as the best overall predictors of disease stage and activity. Our results display how CPET and spirometry data complement each other for sarcoidosis disease staging, and how these tests are able to detect disease activity. Our findings suggest that CPET, a repeatable and non-invasive functional test, should be more routinely performed and taken into account in sarcoidosis patient follow-up.

Cardiopulmonary Exercise Testing in Evaluating Transthyretin Amyloidosis.

Cardiopulmonary exercise testing (CPET) has an established role in the assessment of patients with heart failure. However, data are lacking in patients with transthyretin (ATTR) amyloidosis. To use CPET to characterize the spectrum of functional phenotypes in patients with ATTR amyloidosis and assess their association with the cardiac amyloid burden as well as the association between CPET parameters and prognosis. This single-center study evaluated patients diagnosed with ATTR amyloidosis from May 2019 to September 2022 who underwent CPET at the National Amyloidosis Centre. Of 1045 patients approached, 506 were included and completed the study. Patients were excluded if they had an absolute contraindication to CPET or declined participation. The mean (SD) follow-up period was 22.4 (11.6) months. Comparison of CPET parameters across disease phenotypes (ATTR with cardiomyopathy [ATTR-CM], polyneuropathy, or both [ATTR-mixed]), differences in CPET parameters based on degree of amyloid infiltration (as measured by cardiovascular magnetic resonance [CMR] with extracellular volume mapping), and association between CPET parameters and prognosis. Among the 506 patients with ATTR amyloidosis included in this study, the mean (SD) age was 73.5 (10.2) years, and 457 participants (90.3%) were male. Impairment in functional capacity was highly prevalent. Functional impairment in ATTR-CM and ATTR-mixed phenotypes (peak mean [SD] oxygen consumption [VO2], 14.5 [4.3] mL/kg/min and 15.7 [6.2] mL/kg/min, respectively) was observed alongside impairment in the oxygen pulse, with ventilatory efficiency highest in ATTR-CM (mean [SD] ventilatory efficiency/volume of carbon dioxide expired slope, 38.1 [8.6]). Chronotropic incompetence and exercise oscillatory ventilation (EOV) were highly prevalent across all phenotypes, with both the prevalence and severity being higher than in heart failure from different etiologies. Worsening of amyloid burden on CMR was associated with decline in multiple CPET parameters, although chronotropic response and EOV remained abnormal irrespective of amyloid burden. On multivariable Cox regression analysis, peak VO2 and peak systolic blood pressure (SBP) were independently associated with prognosis (peak VO2: hazard ratio, 0.89 [95% CI, 0.81-0.99; P = .03]; peak SBP: hazard ratio, 0.98 [95% CI, 0.97-0.99; P < .001]). In this study, ATTR amyloidosis was characterized by distinct patterns of functional impairment between all disease phenotypes. A high prevalence of chronotropic incompetence, EOV, and ventilatory inefficiency were characteristic of this population. CPET parameters were associated with amyloid burden by CMR and with peak VO2, and SBP, which have been shown to be independent predictors of mortality. These findings suggest that CPET may be useful in characterizing distinct patterns of functional impairment across the spectrum of amyloid infiltration and predicting outcomes, and potentially offers a more comprehensive method of evaluating functional capacity for future prospective studies.

Metabolic cost of unloading pedalling in different groups of patients with pulmonary hypertension and volunteers

Recently, the parameter internal work (IW) has been introduced as change in oxygen uptake (VO2) between resting and unloading workload in cardiopulmonary exercise testing (CPET). The proportional IW (PIW) was defined as IW divided by VO2 at peak exercise. A second option is to calculate the PIW based on the workload [PIW (Watt)] by considering the aerobic efficiency. The aim of our study was to investigate whether IW and PIW differ between patients with and without pulmonary hypertension and healthy controls. Our study population consisted of 580 patients and 354 healthy controls derived from the Study of Health in Pomerania. The PIW was slightly lower in patients (14.2%) than in healthy controls (14.9%; p = 0.030), but the PIW (Watt) was higher in patients (18.0%) than in the healthy controls (15.9%; p = 0.001). Such a difference was also observed, when considering only the submaximal workload up to the VAT (19.8% in patients and 15.1% in healthy controls; p < 0.001). Since the PIW (Watt) values were higher in patients with pulmonary hypertension, this marker may serve as a useful CPET parameter in clinical practice. In contrast to most of the currently used CPET parameters, the PIW does not require a maximal workload for the patient. Further studies are needed to validate the prognostic significance of the PIW.

Cardiopulmonary Exercise Testing after Surgical Repair of Tetralogy of Fallot-Does Modality Matter?

Despite a successful repair of tetralogy of Fallot (rToF) in childhood, residual lesions are common and can contribute to impaired exercise capacity. Although both cycle ergometer and treadmill protocols are often used interchangeably these approaches have not been directly compared. In this study we examined cardiopulmonary exercise test (CPET) measurements in rToF. Inclusion criteria were clinically stable rToF patients able to perform a cardiac magnetic resonance imaging (CMR) and two CPET studies, one on the treadmill (incremental Bruce protocol) and one on the cycle ergometer (ramped protocol), within 12 months. Demographic, surgical and clinical data; functional class; QRS duration; CMR measures; CPET data and international physical activity questionnaire (IPAQ) scores of patients were collected. Fifty-seven patients were enrolled (53% male, 20.5 ± 7.8 years at CPET). CMR measurements included a right ventricle (RV) end-diastolic volume index of 119 ± 22 mL/m2, a RV ejection fraction (EF) of 55 ± 6% and a left ventricular (LV) EF of 56 ± 5%. Peak oxygen consumption (VO2)/Kg (25.5 ± 5.5 vs. 31.7 ± 6.9; p < 0.0001), VO2 at anaerobic threshold (AT) (15.3 ± 3.9 vs. 22.0 ± 4.5; p < 0.0001), peak O2 pulse (10.6 ± 3.0 vs. 12.1± 3.4; p = 0.0061) and oxygen uptake efficiency slope (OUES) (1932.2 ± 623.6 vs. 2292.0 ± 639.4; p < 0.001) were significantly lower on the cycle ergometer compared with the treadmill, differently from ventilatory efficiency (VE/VCO2) max which was significantly higher on the cycle ergometer (32.2 ± 4.5 vs. 30.4 ± 5.4; p < 0.001). Only the VE/VCO2 slope at the respiratory compensation point (RCP) was similar between the two methodologies (p = 0.150). The majority of CPET measurements differed according to the modality of testing, with the exception being the VE/VCO2 slope at RCP. Our data suggest that CPET parameters should be interpreted according to test type; however, these findings should be validated in larger populations and in a variety of institutions.

Cardiopulmonary exercise test combined with red blood cell distribution width to predict cardiovascular complication of thoracic surgery

Cardiovascular complications in patients undergoing thoracic surgery, which physicians have a limited ability to predict, are often unavoidable and resulting in adverse outcome. Cardiopulmonary exercise testing (CPET), the gold standard of cardiopulmonary function evaluation, has also been proved to be a preoperative risk assessment tool. Meanwhile, elevated red blood cell distribution width (RDW) has surged as a biochemical marker in the occurrence of cardiovascular disease. However, it is yet unclear the value of CPET combined with RDW in predicting cardiovascular complications after thoracic surgery. 50 patients with cardiovascular complications after thoracic surgery were collected as the case group, and 100 thoracic surgery patients were recruited as the control group, with the same gender, age ± 2 years old, and no postoperative complications. After admission, all patients underwent CPET and RDW inspection before surgery, and the results were recorded. The CPET parameter oxygen pulse (VO2/HR) and RDW of the case group were lower than those of the control group (P < 0.05), and the ventilation/carbon dioxide production (VE/VCO2 slope) was significantly higher than control group (P < 0.01). The biochemical parameters hemoglobin (Hb) and Glomerular filtration rate (GFR)) of the case group were lower than those of the control group (P < 0.05), the homocysteine (hCY), creatinine (Cr), operation time and blood loss of the case group were higher than those of the control group (P < 0.05). The RDW had a negative correlation with VO2 max in both overall and control group. The combination of VO2/kg and RDW had the highest diagnostic value in predicting cardiovascular complications. The combination of VO2/kg and RDW has predictive diagnostic value and is more suitable for predicting postoperative complications of thoracic surgery.

Respiratory exchange ratio overshoot during exercise recovery: a promising prognostic marker in HFrEF.

Transient increases (overshoot) in respiratory gas analyses have been observed during exercise recovery, but their clinical significance is not clearly understood. An overshoot phenomenon of the respiratory exchange ratio (RER) is commonly observed during recovery from maximal cardiopulmonary exercise testing (CPET), but it has been found reduced in patients with heart failure with reduced ejection fraction (HFrEF). The aim of the study was to analyze the clinical significance of these RER recovery parameters and to understand if these may improve the risk stratification of patients with HFrEF. This cross-sectional study includes HFrEF patients who underwent functional evaluation with maximal CPET for the heart transplant checklist at our Sports and Exercise Medicine Division. RER recovery parameters, including RER overshoot as the percentual increase of RER during recovery (RER mag), have been evaluated after CPET with assessment of hard clinical long-term endpoints (MACEs/deaths and transplant/LVAD-free survival). A total of 190 patients with HFrEF and 103 controls were included (54.6 ± 11.9years; 73% male). RER recovery parameters were significantly lower in patients with HFrEF compared to healthy subjects (RER mag 24.8 ± 14.5% vs 31.4 ± 13.0%), and they showed significant correlations with prognostically relevant CPET parameters. Thirty-three patients with HFrEF did not present a RER overshoot, showing worse cardiorespiratory fitness and efficiency when compared with those patients who showed a detectable overshoot (VO2 peak: 11.0 ± 3.1 vs 15.9 ± 5.1ml/kg/min; VE/VCO2 slope: 41.5 ± 8.7 vs 32.9 ± 7.9; ΔPETCO2: 2.75 ± 1.83 vs 4.45 ± 2.69mmHg, respectively). The presence of RER overshoot was associated with a lower risk of cardiovascular events and longer transplant-free survival. RER overshoot represents a meaningful cardiorespiratory index to monitor during exercise gas exchange evaluation; it is an easily detectable parameter that could support clinicians to comprehensively interpreting patients' functional impairment and prognosis. CPET recovery analyses should be implemented in the clinical decision-making of advanced HF.

Cardiopulmonary Exercise Testing in Transgender and Gender-Diverse Patients: The Influence of Sex and Gender on Predicted Aerobic Capacity

BackgroundSex assigned at birth (SAB) is currently used to calculate predicted normative values for oxygen consumption (VO2) during cardiopulmonary exercise testing (CPET) in transgender and gender diverse (TGD) patients. It is unclear if this is physiologically valid once gender-affirming hormonal therapy (GAHT) has been instituted. Research QuestionWhat are the changes in functional aerobic capacity (FAC) and in percentage of predicted (%pred) peak VO2 when gender is used, instead of SAB, to estimated normative predicted values among TGD patients >14 years of age who are receiving GAHT? Study Design and MethodsWe retrospectively analyzed 16 referred TGD patients (8 transgender men, 8 transgender women) receiving GAHT therapy at the time of the test. Data collected and analyzed included: clinical indication for CPET, biometrics (age, height, and weight), CPET parameters (treadmill, Mayo Clinic protocol, without chest binder), chest imaging, echocardiographic results, and hemoglobin levels. ResultsIn transgender women, the use of gender congruent normative predictive values, instead of SAB, significantly increased FAC (69.70 ± 4.35 vs. 87.82 ± 5.15 [%]; mean ± SE; for SAB and gender, respectively; p= <0.0001) and %pred peak VO2 (66.53 ± 4.17 vs. 89.69 ± 5.60 [%]; mean ± SE; for SAB and gender, respectively; p= <0.0001). In transgender men, the use of gender congruent normative predictive values showed that both FAC and %pred peak VO2 significantly decreased (approximately 20% and 25%, respectively). Deconditioning was the most frequent CPET finding among transgender men. InterpretationAmong TGD individuals receiving GAHT, the use of gender to calculate normative values affects %pred peak exercise VO2 and FAC significantly. Body composition changes after GAHT require regular monitoring of muscle strength, lean body mass, and aerobic capacity. Cardiopulmonary symptoms among TGD patients should be assessed with these variables in mind –especially in the presence of chronic cardiac and pulmonary diseases.

Body plethysmography - additional information on exercise capacity in patients with congenital heart disease?

In each cardiopulmonary exercise test (CPET), resting spirometry is performed in advance. In patients with a congenital heart defect (CHD), lung volumes are often impaired. This study investigates correlations between lung volumes and CPET parameters and determines, whether body plethysmography provides substantial additional information for these patients. Data from 102 patients (23.8 ± 10.4years of age, 39 female) with various forms of CHD were examined from April 2018 to October 2022. All patients underwent spirometry (measuring forced vital capacity, FVC and forced expiratory volume in 1s, FEV1), body plethysmography (measuring total lung capacity, TLC) and an exhausting CPET. Data is presented as the median and interquartile range (z-scores) and correlated with Spearman's rho. Fifty-five% of all patients had normal results in lung function and 45% had normal peak oxygen uptake (≥ 80% predicted in peak VO2). Patients with impaired lung function were significantly more likely to have low exercise capacity (Fisher's exact test: p = 0.028). FVC z-values and %predicted peak VO2 (r = 0.365, p < 0.001) correlated significantly as well as FEV1_z and %predicted peak VO2 (r = 0.320, p = 0.001), and TLC z-values and %predicted peak VO2 (r = 0.249, p = 0.012). No correlation was found between FEV1/FVC z-values and %predicted peak VO2 (r = -0.043, p = 0.670). Spirometry and exercise capacity positively correlate, also in CHD patients. However, body plethysmography does not provide additional or improved prediction and is therefore only recommended in noteworthy results in spirometry to exclude further lung co-morbidities.