Predicted Peak VO2 Research Articles

Long-Term Functional Limitations on Cardiopulmonary Exercise Testing in Emotion-Triggered Takotsubo Syndrome.

Background: In patients with prior Takotsubo syndrome (TTS), long-lasting functional cardiac limitations were described as compared with normal subjects. Emotion-triggered Takotsubo syndrome (E-TTS) has more favorable outcomes than TTS preceded by a physical trigger or by no identifiable factors. The aim of the present study was to assess long-term cardiac functional limitations in a cohort of asymptomatic E-TTS patients. Methods: We enrolled n = 40 asymptomatic patients with a diagnosis of E-TTS. Cardiopulmonary exercise tests (CPET) were performed at 30 (12-40) months median follow-up from the acute event. A cohort of n = 40 individuals matched for age, sex, body mass index and comorbidities served as control. Results: Despite recovery of left ventricular ejection fraction, patients with prior E-TTS had lower peak VO2 and percentage of predicted peak VO2 (17.8 ± 3.6 vs. 22.1 ± 6.5; p < 0.001 and 75.2 ± 14.1% vs. 100.6 ± 17.1%, p < 0.001), VO2 at anaerobic threshold (AT) (11.5 [10.1-12.9] vs. 14.4 [12.5-18.7]; p < 0.001), peak O2 pulse (9.8 ± 2.5 vs. 12.9 ± 3.5; p < 0.001) and higher VE/VCO2 slope (30.5 ± 3.7 vs. 27.3 ± 3.5; p < 0.001) compared with matched controls. We found no statistically significant differences in heart rate reserve (HRR), respiratory equivalent ratio (RER), mean blood pressure and peak PetCO2 between patients and controls. Conclusions: Despite its favorable outcome, patients with E-TTS in our population were found to have subclinical long-term functional cardiac limitations as compared with a control cohort.

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.

A COMPARISON OF GUIDELINES FOR HEART TRANSPLANT CONSIDERATION BASED ON CPET DATA

https://youtu.be/tfol-46xG-o BACKGROUND The International Society for Heart and Lung Transplantation (ISHLT) recommends using peak oxygen uptake (VO2≤12 mL/kg/min), percent predicted peak VO2 (ppVO2≤50%), or the ventilation to carbon dioxide slope (VE/VCO2 slope&amp;gt;35) to guide listing for heart transplantation (HTx) in patients with heart failure with reduced ejection fraction (HFrEF). Data comparing the mortality rates between each of these thresholds is lacking. The purpose of this retrospective cohort study was to describe the 3-year mortality rate among patients with HFrEF based on the ISHLT recommendations. METHODS This was a secondary analysis of a combined cohort of patients (≥18 years) with HFrEF from Henry Ford Hospital (n=1,063) and the HF-ACTION study (n=1,772). The cohort was limited to patients who completed a cardiopulmonary exercise test on a treadmill and were prescribed a beta-adrenergic blockade at the time of the test. The primary outcome was probability of all-cause mortality at 3 years based on Kaplan-Meier estimates. Patients were censored at the date of HTx, left ventricular assist device implant, or last known alive. Mortality rates were calculated for patients with a peak VO2≤12 mL/kg/min, ppVO2≤50%, and VE/VCO2 slope&amp;gt;35. The cohort was stratified by sex, age, obesity (body mass index [BMI]&amp;gt; 30 kg/m2), and peak respiratory exchange ratio (RER). Mortality rates were compared to the 3-year mortality post HTx reported by ISHLT. RESULTS In our combined cohort (n=2,775; age=57±13 y; 19% women; 48% non-white), 3-year mortality for peak VO2≤12 mL/kg/min, ppVO2≤50%, and VE/VCO2 slope&amp;gt;35 was 30%, 31%, and 28%, respectively. Each of these are higher than the 3-year mortality post HTx (20%). Similar results were observed by age below/above 50 y, BMI &amp;lt; versus &amp;gt; 30 kg/m2, RER ≤ versus &amp;gt;1.05, and within men. However, among women the 3-year mortality was 18% for peak VO2≤12 mL/kg/min, 25% for ppVO2≤50%, and 21% for VE/VCO2 slope&amp;gt;35. CONCLUSIONS ISHLT recommendations to guide listing for HTx for peak VO2≤12 mL/kg/min, ppVO2≤50%, and VE/VCO2 slope&amp;gt;35 are associated with a higher 3-year mortality than patients post HTx irrespective of age, obesity, and RER. However, among women only ppVO2≤50% and VE/VCO2 slope&amp;gt;35 identify patients with 3-year mortality that is higher than HTx.

Prediction of peak oxygen consumption using cardiorespiratory parameters from warmup and submaximal stage of treadmill cardiopulmonary exercise test.

This study investigates the quality of peak oxygen consumption (VO2peak) prediction based on cardiac and respiratory parameters calculated from warmup and submaximal stages of treadmill cardiopulmonary exercise test (CPET) using machine learning (ML) techniques and assesses the importance of respiratory parameters for the prediction outcome. The database consists of the following parameters: heart rate (HR), respiratory rate (RespRate), pulmonary ventilation (VE), oxygen consumption (VO2) and carbon dioxide production (VCO2) obtained from 369 treadmill CPETs. Combinations of features calculated based on the HR, VE and RespRate time-series from different stages of CPET were used to create 11 datasets for VO2peak prediction. Thirteen ML algorithms were employed, and model performances were evaluated using cross-validation with mean absolute percentage error (MAPE), R2 score, mean absolute error (MAE), and root mean squared error (RMSE) calculated after each iteration of the validation. The results demonstrated that incorporating respiratory-based features improves the prediction of VO2peak. The best results in terms of R2 score (0.47) and RMSE (5.78) were obtained for the dataset which included both cardiac- and respiratory-based features from CPET up to 85% of age-predicted HRmax, while the best results in terms of MAPE (10.5%) and MAE (4.63) were obtained for the dataset containing cardiorespiratory features from the last 30 seconds of warmup. The study showed the potential of using ML models based on cardiorespiratory features from submaximal tests for prediction of VO2peak and highlights the importance of the monitoring of respiratory signals, enabling to include respiratory parameters into the analysis. Presented approach offers a feasible alternative to direct VO2peak measurement, especially when specialized equipment is limited or unavailable.

Usual-paced 400 m long distance corridor walk estimates cardiorespiratory fitness among older adults: The Study of Muscle, Mobility and Aging.

Cardiopulmonary exercise testing (CPET), the gold-standard method to quantify cardiorespiratory fitness (CRF), is not always feasible due to cost, access, and burden. The usual-paced 400 m long distance corridor walk (LDCW), a measure of mobility among older adults, may provide an alternate method to assess CRF. The purpose of this study was to develop and validate an estimating equation to estimate VO2 peak from average 400 m walking speed (WS) among participants in the Study of Muscle, Mobility and Aging (SOMMA). At baseline, women (58%) and men age 70 years and older enrolled in SOMMA (N = 820, 76.2 ± 4.9 years, 86% Non-Hispanic White) completed a 400 m LDCW (400 m WS = 400 m/completion time in seconds) and symptom-limited maximal CPET (Modified Balke Protocol). VO2 peak (mL/kg/min) was considered the highest 30-second average oxygen consumption during CPET. Other covariates included: age, sex, race, physical activity (7-day wrist-worn accelerometer), physical function (Short Physical Performance Battery, range 0-12), perceived physical fatigability (Pittsburgh Fatigability Scale, range 0-50), and Borg Rating of Perceived Exertion (RPE, range 6-20) at completion of the 400 m LDCW. Stepwise linear regression was used. Internal validation was completed using data-splitting method (70%; 30%). Mean VO2 peak was 20.2 ± 4.8 mL/kg/min and mean 400 m WS was 1.06 ± 0.2 m/s. Each 0.05 m/s increment in 400 m WS was associated with a 0.40 mL/kg/min higher VO2 peak after covariate adjustment. An estimating equation including 400 m WS, age, sex, race, and RPE was developed. Internal validation showed low overall bias (-0.26) and strong correlation (r = 0.71) between predicted and measured VO2 peak values. Bland-Altman plot and regression analyses indicated predicted VO2 peak was an acceptable alternative, despite mean underestimation of 4.53 mL/kg/min among the highly fit. Usual-paced 400 m LDCW strongly correlates with direct measures of CRF during CPET in older adults with lower fitness and can be used to test both fitness and function.

Development of deep-learning models for real-time anaerobic threshold and peak VO2 prediction during cardiopulmonary exercise testing.

Exercise intolerance is a clinical feature of patients with heart failure (HF). Cardiopulmonary exercise testing (CPET) is the first-line examination for assessing exercise capacity in patients with HF. However, the need for extensive experience in assessing anaerobic threshold (AT) and the potential risk associated with the excessive exercise load when measuring peak oxygen uptake (peak VO2) limit the utility of CPET. This study aimed to use deep-learning approaches to identify AT in real time during testing (defined as real-time AT) and to predict peak VO2 at real-time AT. This study included the time-series data of CPET recorded at the Department of Cardiovascular Medicine, Kyushu University Hospital. Two deep neural network models were developed to: (i) estimate the AT probability using breath-by-breath data and (ii) predict peak VO2 using the data at the real-time AT. The eligible CPET contained 1472 records of 1053 participants aged 18-90 years and 20% were used for model evaluation. The developed model identified real-time AT with 0.82 for correlation coefficient (Corr) and 1.20 mL/kg/min for mean absolute error (MAE), and the corresponding AT time with 0.86 for Corr and 0.66 min for MAE. The peak VO2 prediction model achieved 0.87 for Corr and 2.25 mL/kg/min for MAE. Deep-learning models for real-time CPET analysis can accurately identify AT and predict peak VO2. The developed models can be a competent assistant system to assess a patient's condition in real time, expanding CPET utility.

A Reference Equation for Peak Oxygen Uptake for Pediatric Patients Who Undergo Treadmill Cardiopulmonary Exercise Testing

Pediatric patients are often referred to cardiopulmonary exercise testing (CPET) laboratories for assessment of exercise-related symptoms. For clinicians to understand results in the context of performance relative to peers, adequate fitness-based prediction equations must be available. However, reference equations for prediction of peak oxygen uptake (VO2peak) in pediatrics are largely developed from field-based testing, and equations derived from CPET are primarily developed using adult data. Our objective was to develop a pediatric reference equation for VO2peak. Clinical CPET data from a validation cohort of 1,383 pediatric patients aged 6 to 18years who achieved a peak respiratory exchange ratio ≥1.00 were analyzed to identify clinical and exercise testing factors that contributed to the prediction of VO2peak from tests performed using the Bruce protocol. The resultant prediction equation was applied to a cross-validation cohort of 1,367 pediatric patients. Exercise duration, gender, weight, and age contributed to the prediction of VO2peak, generating the following prediction equation: (R2=0.645, p <0.001, standard error of the estimate=6.19ml/kg/min): VO2peak (ml/kg/min) =16.411+ 3.423 (exercise duration [minutes]) - 5.145 (gender [0=male, 1=female]) - 0.121 (weight [kg])+0.179 (age [years]). This equation was stable across the age range included in the present study, with differences ≤0.5ml/kg/min between mean measured and predicted VO2peak in all age groups. In conclusion, this study represents what we believe is the largest pediatric CPET-derived VO2peak prediction effort to date, and this VO2peak prediction equation provides clinicians who perform and interpret exercise tests in pediatric patients with a resource with which to better quantify fitness when CPET is not available.

The effect of mild to moderate COVID-19 infection on the cardiorespiratory fitness of firefighters.

An adequate level of cardiorespiratory fitness (CRF) is critical for firefighters to perform the strenuous and physiologically demanding work of firefighting safely and effectively. The coronavirus disease 2019 (COVID-19) has been shown to negatively impact CRF in both the acute phase and longer-term following infection. This study aimed to determine changes to the CRF of firefighters pre- to post-mild to moderate COVID-19 infection and to investigate the impact of days past COVID-19 infection on change in CRF. CRF measures from cardiopulmonary exercise testing (CPET) at annual occupational health exams that occurred pre-COVID-19 infection in 2019 were obtained for firefighters from seven Arizona fire departments. Measures were compared to CPET evaluations from annual health exams the following year in a cohort of firefighters who self-reported mild to moderate illness following COVID-19 infection between exams. Among a cohort of 103 firefighters, mean age 40 ± 9 years, CRF [as measured by peak oxygen consumption (VO2)] declined by an average of 2.55 ml·kg-1·min-1 or 7.3% (d = -0.38, p < 0.001) following COVID-19 infection (mean time from COVID-19 infection to CPET was 110 ± 78 days). The number of days past COVID-19 infection showed a small, yet significant, relationship to peak VO2 (r = 0.250, p = 0.011). Estimated marginal effects indicated that when biological sex, age, and BMI are controlled for, predicted peak VO2 returned to pre-COVID-19 values ~300 days after COVID-19 infection. Peak VO2 (ml·kg-1·min-1) declined 7.3% among firefighters an average of 110 days past reporting mild to moderate COVID-19 infection. This decrease has implications for the operational readiness and safety of firefighters.

Fragmented QRS complexes in veteran athletes

Abstract Background QRS fragmentation (fQRS), characterized by multiple peaks within the QRS, is considered an adverse risk marker that may indicate underlying myocardial fibrosis and has been implicated in cardiomyopathies. The presence of fQRS is often noted in pre-participation screening of athletes. In this study, we aimed to investigate the prevalence and clinical significance of fQRS in a cohort of ostensibly fit veteran athletes (VA). Methods We recruited 314 predominantly Caucasian VA's with a history of endurance exercise and no traditional risk factors for coronary artery disease. Participants underwent a 12-lead electrocardiogram, cardiopulmonary exercise testing (CPET), 24-hour Holter monitoring, and cardiac magnetic resonance imaging (CMR). fQRS was categorized as &amp;gt;2 consecutive leads using established criteria (1). Results fQRS in 2 or more contiguous leads was identified in 12% of VA's. The presence of fQRS was more prevalent in males and increased with age (p &amp;lt; 0.05). There were no significant differences in ECG conduction indices. When CMR parameters were considered, the presence of fQRS was associated with increased left ventricular (LV) mass index and increased right ventricular (RV) function. There was no relationship with the presence of late gadolinium enhancement. Athletes with fQRS achieved a significantly lower predicted peak VO2 and trended towards lower peak resistance on CPET. No relationship was observed with total ventricular premature beat count or the presence of complex ectopy on 24-hour Holter monitoring. Conclusions fQRS in 2 or more contiguous leads is commonly present amongst male Caucasian VA’s, and its prevalance increases with age. It is associated with greater LV mass and increased RV ejection fraction. Athletes with fQRS may achieve a lower percentage predicted VO2 max compared to those without. Furthermore, FQRS did not predict late gadolinium enhancement, increased VPB count or complex ectopy.Comparing VAs with FQRSQRS-fragmentation patterns (Das et al)

Relationship between the right ventricular function and MECKI score in patients with advanced heart failure

Abstract Background Three- dimensional echocardiography (3DE) is an attractive technique for assessment of RV wrapping around the conical left ventricle and MECKI score is a strong predictor of prognosis in patients with advanced heart failure. Purpose We aimed to evaluate the relationship between the right ventricular function obtained by 3DE and MECKI Score in patients with advanced heart failure. Methods The Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score was calculated by an online free calculator using parameters peak oxygen uptake (% predicted value) and VE/CO2 slope values obtained by CPET, blood samples such as hemoglobin, sodium, MDRD and left ventricular ejection fraction (LVEF).(1) Results The 43 patients with sinus rhythm who were candidates for heart transplantation or left ventricular assist device (LVAD) therapy between June 2022 and January 2023 were included in the study. The majority of the patients were male (% 81). The mean 3D LV EF was % 22 ± 3.8, the mean value for peak VO2 max obtained by CPET was 15 ± 5.8 ml/kg/min and the median value for VE/CO2 slope was 34 (24-99). When the right ventricular parameters were compared according to the median value of 34, the right ventricle was larger and parameters of the right ventricular systolic function were worse in patients with the higher VE/CO2 slope values. (Figure 1). The mean value for percentage of predicted peak VO2 max was % 52 ± 16 and the median for the MECKI Score was 9.3 (1.8-86). By univariate and multivariate regression analyses, only the 3D RV basal diameter was found independently associated with peak VO2 max. Also, the VECO2 slope was found independently associated only with 3D RV TAPSE. Also these two parameters, 3D RV basal diameter and 3D RV TAPSE were found independent predictors of MECKI score. In ROC analysis, the cut off value 40.9 mm for 3D RV basal diameter to predict MECKI score with sensitivity and specificity were % 90 and % 68 , respectively (AUC:0.792). Also, AUC was 0.784 for the cut off value of 7.7 mm for 3D RV TAPSE with the sensitivity % 90 and specificity % 81. (Figure 2). Conclusion The major findings in this study were RV basal diameter was an independent predictor of the peak VO2 max value and RV 3D TAPSE was an independent predictor of the VECO2 slope. These results suggest that, while the basal diameter of the right ventricle, in other words, the size of the right ventricle effects peak oxygen consumption, the O2 transport and utilization, 3D TAPSE, namely systolic function of the right ventricle effects the ability to remove C02 from the whole body. Also these two parameters were found independent predictors of the MECKI score which is a strong predictor of prognosis in patients with advanced heart failure.Figure 1Figure 2

Abstract 18236: Enhancing Predictive Accuracy of H2FPEF Score in Suspected HFpEF by Incorporating Left Atrial Reservoir Strain

Introduction: Diagnosing HFpEF can be challenging, but the H 2 FPEF score is a valuable tool for clinical decision-making. Atrial fibrillation (AF) plays a significant role in this score, creating challenges for diagnosis in patients without AF or with paroxysmal AF. Left atrial reservoir strain (LArS) has emerged as a promising indicator for both AF and HFpEF. This study explores how incorporating LArS can enhance the predictive ability of the H 2 FPEF score for exercise capacity in outpatients with suspected HFpEF. Methods: This cross-sectional study has a sample size of 283 patients with suspected HFpEF. We collected clinical and echocardiographic data and compared LArS values across different H 2 FPEF score categories. Additionally, we analyzed a subgroup of 129 patients who underwent a Cardiopulmonary Exercise Test (CPET) to evaluate the effectiveness of the H 2 FPEF score and LArS in predicting Peak VO 2 . To further comprehend the contribution of each feature in the performance of the H 2 FPEF score, we used Shapley Additive Explanations (SHAP) analysis. Results: Most patients were female (63%), age of 60 (±12) years and LVEF of 60 (±5.2)%. Patients with low scores had a LArS of 32.6 (± 6.8)%, while those with moderate and high scores had probabilities of 26(± 8.2)% and 16 (±8.2)%, respectively (p&lt;0.001). The H 2 FPEF score demonstrated an AUC of 0.74 (95% CI: 0.64-0.84) in predicting peak VO 2 , whereas LArS exhibited an AUC of 0.71 (95% CI: 0.62-0.80). Incorporating LArS into the score improved its performance, resulting in an AUC of 0.82 (95% CI: 0.75-0.89). The SHAP analysis revealed that LArS had a significant impact as the most important feature (Figure 1), while the importance of the atrial fibrillation criterion decreased significantly. Conclusions: Our findings show that integrating LArS improves the diagnostic performance of the H 2 FPEF score and offers a valuable alternative to the AF criterion within the H 2 FPEF algorithm.

Abstract 17716: Comprehensive Cardiac Rehabilitation Following Myocardial Infarction Improves Clinical Outcomes Regardless of Exercise Capacity in a Long-Term Follow-Up

Background: Reduced exercise capacity is recognized as a prognostic indicator of adverse outcomes in patients with myocardial infarction (MI). However, there is limited research evaluating the effectiveness of comprehensive cardiac rehabilitation (CR) in this population. Here, we show for the first time that participation in CR can improve the prognosis of MI patients with reduced exercise capacity in a long-term study. Methods: This cohort study included 610 consecutive patients with MI who underwent percutaneous coronary intervention (PCI) between 2008 and 2015. Patients who received supervised CR were divided into two groups according to the duration of CR: the non-CR group (only hospitalization) and the CR group (continued to outpatient-CR). Within the CR group, patients were further divided into a reduced exercise capacity group (% predicted peak VO2 &lt;80%) and a preserved exercise capacity group (≥80%). Comprehensive CR consisted of a 150-day supervised exercise program at the anaerobic threshold (AT) performed in the hospital under the supervision of a multidisciplinary team. Major adverse cardiovascular events (MACE) were compared among groups. Results: Mean follow-up was 6.1 ± 4.0 years. The MI patients were divided into three groups: the non-CR group (n = 180), the CR group with reduced exercise capacity (n = 241, peak VO2: 17.2 ± 3.9 ml/min/kg) and with preserved exercise capacity (n = 147, peak VO2: 23.1 ± 4.6 ml/min/kg). There was no significant difference in the improvement of the lower limb exercise capacity index, AT, peak VO2 and risk of MACE between the CR groups with reduced and preserved exercise capacity. However, the risk of MACE was lower in the CR groups compared with the non-CR group (log-rank p = 0.014). Multivariable Cox regression analysis showed that chronic kidney disease (aHR 1.89, 95% CI 1.19-3.01, p &lt; 0.01), non-Killip class 1 (aHR 1.90, 95% CI 1.01-3.57, p = 0.047) and CR participation (aHR 0.57, 95% CI 0.36-0.90, p = 0.015) were independent predictors of MACE. Conclusions: Comprehensive CR after PCI in patients with MI effectively reduces the occurrence of MACE, regardless of their exercise capacity. We should also actively encourage patients with low exercise capacity to participate in comprehensive CR.

The Effects of a Cardiac Rehabilitation Program on Endothelial Progenitor Cells and Inflammatory Profile in Patients with Chronic Heart Failure of Different Severity.

Endothelial dysfunction and inflammation are common pathophysiological characteristics of chronic heart failure (CHF). Endothelial progenitor cells (EPCs) are recognized as useful markers of vascular damage and endothelial repair. The aim of this study was to investigate the effects of a cardiac rehabilitation program on EPCs and inflammatory profile in CHF patients of different severity. Forty-four patients with stable CHF underwent a 36-session cardiac rehabilitation program. They were separated into two different subgroups each time, according to the median peak VO2, predicted peak VO2, VE/VCO2 slope, and ejection fraction. EPCs, C-reactive protein (CRP), interleukin 6 (IL-6), interleukin 10 (IL-10), and vascular endothelial growth factor (VEGF) were measured. Flow cytometry was used for the quantification of EPCs. Mobilization of EPCs increased and the inflammatory profile improved within each severity group (p < 0.05) after the cardiac rehabilitation program, but there were no statistically significant differences between groups (p > 0.05). A 36-session cardiac rehabilitation program has similar beneficial effects on the mobilization of EPCs and on the inflammatory profile in patients with CHF of different severity.

Cardiopulmonary exercise testing augments watchful waiting in asymptomatic severe primary mitral regurgitation.

Our aim is to describe the use of cardiopulmonary exercise testing in watchful waiting for asymptomatic severe primary mitral regurgitation. Between October 2016 and October 2017, ten patients with asymptomatic severe primary mitral regurgitation underwent watchful waiting in a single centre. Baseline assessment included history, physical examination, transthoracic echocardiogram and cardiopulmonary exercise testing. Patients were re-evaluated every 6months with history, physical examination and transthoracic echocardiogram; and at 12months with cardiopulmonary exercise testing. At 1year follow up, five patients remained asymptomatic with no significant change in left ventricular ejection fraction (p = 0.18). This was associated with no significant change in cardiopulmonary exercise testing parameters. However, five patients developed early new symptoms or changes in echocardiographic parameters with a significant fall in left ventricular ejection fraction (p < 0.01). This was associated with a significant fall in anaerobic threshold (p = 0.04) and four of the five patients having an abnormal percentage predicted peak VO2 at 1year follow up. Changes in symptomatic status or echocardiographic parameters during a watchful waiting approach for asymptomatic severe primary mitral regurgitation is associated with a significant reduction in cardiopulmonary exercise testing parameters.

Three-dimensional echocardiography for the evaluation of hypertrophic cardiomyopathy patients: relation to symptoms and exercise capacity

Patients with hypertrophic cardiomyopathy may exhibit impaired functional capacity, associated with increased morbidity and mortality. Systolic function is one of the determinants of functional capacity. Early identification of systolic disfunction may identify patients at risk for adverse outcomes. Myocardial deformation parameters, derived from three-dimensional (3D) speckle-tracking echocardiography (3DSTE) are useful tools to assess left ventricular systolic function, and are often abnormal before a decline in ejection fraction is seen. The aim of this study was to evaluate the correlation between myocardial deformation parameters obtained by 3DSTE and functional capacity in patients with hypertrophic cardiomyopathy. Seventy-four hypertrophic cardiomyopathy adult patients were prospectively evaluated. All patients underwent a dedicated 2D and 3D echocardiographic examination and cardiopulmonary exercise testing (CPET). Values of 3D global radial (GRS), longitudinal (3DGLS) and circumferential strain (GCS) were overall reduced in our population: 99% (n = 73) of the patients had reduced GLS, 82% (n = 61) had reduced GRS and all patients had reduced GCS obtain by 3DSTE. Average peak VO2 was 21.01 (6.08) ml/Kg/min; 58% (n = 39) of the patients showed reduced exercise tolerance (predicted peak VO2 < 80%). The average VE/VCO2 slope was 29.0 (5.3) and 16% (n = 11) of the patients had impaired ventilatory efficiency (VE/VCO2 > 34). In multivariable analysis, 3D GLS (β1 = 0.10, 95%CI: 0.03;0.23, p = 0.014), age (β1 = -0.15, 95%CI: -0.23; -0.05, p = 0.002) and female gender (β1 = -5.10, 95%CI: -7.7; -2.6, p < 0.01) were independently associated with peak VO2. No association was found between left ventricle ejection fraction obtain and peak VO2 (r = 0.161, p = 0.5). Impaired myocardial deformation parameters evaluated by 3DSTE were associated with worse functional capacity assessed by peak VO2.

Longitudinal Follow-Up of Children With HLHS and Association Between Norwood Shunt Type and Long-Term Outcomes: The SVR III Study.

In the SVR trial (Single Ventricle Reconstruction), newborns with hypoplastic left heart syndrome were randomly assigned to receive a modified Blalock-Taussig-Thomas shunt (mBTTS) or a right ventricle-to-pulmonary artery shunt (RVPAS) at Norwood operation. Transplant-free survival was superior in the RVPAS group at 1 year, but no longer differed by treatment group at 6 years; both treatment groups had accumulated important morbidities. In the third follow-up of this cohort (SVRIII [Long-Term Outcomes of Children With Hypoplastic Left Heart Syndrome and the Impact of Norwood Shunt Type]), we measured longitudinal outcomes and their risk factors through 12 years of age. Annual medical history was collected through record review and telephone interviews. Cardiac magnetic resonance imaging (CMR), echocardiogram, and cycle ergometry cardiopulmonary exercise tests were performed at 10 through 14 years of age among participants with Fontan physiology. Differences in transplant-free survival and complication rates (eg, arrhythmias or protein-losing enteropathy) were identified through 12 years of age. The primary study outcome was right ventricular ejection fraction (RVEF) by CMR, and primary analyses were according to shunt type received. Multivariable linear and Cox regression models were created for RVEF by CMR and post-Fontan transplant-free survival. Among 549 participants enrolled in SVR, 237 of 313 (76%; 60.7% male) transplant-free survivors (mBTTS, 105 of 147; RVPAS, 129 of 161; both, 3 of 5) participated in SVRIII. RVEF by CMR was similar in the shunt groups (RVPAS, 51±9.6 [n=90], and mBTTS, 52±7.4 [n=75]; P=0.43). The RVPAS and mBTTS groups did not differ in transplant-free survival by 12 years of age (163 of 277 [59%] versus 144 of 267 [54%], respectively; P=0.11), percentage predicted peak Vo2 for age and sex (74±18% [n=91] versus 72±18% [n=84]; P=0.71), or percentage predicted work rate for size and sex (65±20% versus 64±19%; P=0.65). The RVPAS versus mBTTS group had a higher cumulative incidence of protein-losing enteropathy (5% versus 2%; P=0.04) and of catheter interventions (14 versus 10 per 100 patient-years; P=0.01), but had similar rates of other complications. By 12 years after the Norwood operation, shunt type has minimal association with RVEF, peak Vo2, complication rates, and transplant-free survival. RVEF is preserved among the subgroup of survivors who underwent CMR assessment. Low transplant-free survival, poor exercise performance, and accruing morbidities highlight the need for innovative strategies to improve long-term outcomes in patients with hypoplastic left heart syndrome. URL: https://www. gov; Unique identifier: NCT0245531.

A VO2peak prediction model in older adults' patients with Parkinson's disease

IntroductionCardiopulmonary function is compromised in people with Parkinson's Disease (PD) and might be related with mortality in advanced stages of the disease. Therefore, estimating the peak oxygen uptake (VO2peak) to monitor its progression overtime and to prescribe exercise is important in clinical context. This study aimed at developing a VO2peak prediction model for older adults' patients with PD based on functional tests used in the physiotherapy clinical settings. Material and methodsEighteen patients with PD (63.8 ± 6.6 years old) took part in the study. All participants underwent a basic anthropometry, functional tests, fulfilled a physical activity questionnaire (IPAQ-S) and cardiopulmonary exercise testing on a cycle ergometer. Linear regression and distributional assumptions were performed to develop the prediction model. The Bland-Altman plots were applied for the agreement analysis. ResultsThe best prediction model included gender, age, waist circumference, BMI, IPAQ-S score, and SPPB functional test score (R2 = 0.87; estimation error: 2.19 ml·kg·min−1; p < 0.001). The distribution assumptions showed validity of the model (p > 0.05), the estimation bias showed a mean of 0.0056 and no pair of data were outside the limits of agreement according to the Bland-Altman diagram. ConclusionsAccessible, simple, and low-cost variables were useful for validly predicting VO2peak in patients with PD.

Effectiveness of home-based exercise in breast cancer survivors: a randomized clinical trial

BackgroundBreast cancer patients are recommended to engage in regular exercise. In developing countries, where there is a lack of facilities to offer specialized, supervised exercise for this population, regularly exercising might be a challenge. We aimed to evaluate the effectiveness of a home-based intervention in this population.MethodsBreast cancer survivors were randomly assigned to either the home-based exercise program or the usual care group. Exercise intervention included walking, balance, and stretch exercises, along with weekly follow-up telephone calls. Quality of life (QOL) was evaluated using EORTC QLQ-C30 and EORTC QLQ-BR23 questionnaires and the predicted VO2 peak was measured using the Ebbeling submaximal treadmill test.ResultsEighty-nine patients were enrolled in the study. Reported minutes of exercise gradually increased from 40.7 min per week in week 1 to 116.9 min per week in week 12. This intervention improved global QOL (P = 0.001), social functioning (P = 0.04), and the predicted VO2 peak (P = 0.01).ConclusionThis home-based exercise regime effectively increased quality of life and physical activity levels.Trial registryIranian Registry of Clinical Trials identifier: IRCT20140810018746N1, prospectively registered 08/01/2018, https://en.irct.ir/trial/27959.

Left atrial stiffness in predicting poor exercise oxygen consumption and ventilatory inefficiency

Abstract Funding Acknowledgements Type of funding sources: None. Background and Introduction Cardiopulmonary exercise test (CPET) provides integrative information of cardiovascular, pulmonary, muscular, and cellular oxidative systems. Peak exercise O2 consumption (VO2) and ventilatory efficiency (VE/VCO2) are potent predictors of poor outcome in heart failure (HF). Purpose We studied to find echocardiographic parameters to predict peak VO2 and VE/VCO2. Methods We analyzed 680 patients who underwent CPET and supine bicycle stress echocardiography simultaneously. CPET was performed using semi-supine ramp bicycle exercise with encouraging R &amp;gt; 1.0. Results Both poor exercise tolerance (peak VO2 &amp;lt; 14 mL/kg/min) and ventilatory inefficiency (VE/VCO2 &amp;gt; 36) were associated with age, LV mass index, LV ejection fraction, baseline or exercise E/e’, TR velocity, LA strain, peak apical rotation, and LA stiffness ((E/e’)/LA strain). In multivariate analysis, only LA stiffness was highly associated in both poor exercise tolerance(p &amp;lt; 0.001, odds ratio 0.96, 95% CI [0.94 0.98]) and ventilatory inefficiency(p&amp;lt;0.001, odds ratio 1.05, 95% CI [1.02 1.08]). Conclusion LA stiffness is independently associated with poor exercise tolerance and ventilatory inefficiency.

Effect of voxelotor on cardiopulmonary testing in youths with sickle cell anemia in a pilot study.

Individuals with sickle cell anemia (SCA) exhibit decreased exercise capacity. Anemia limits oxygen-carrying capacity and affects cardiopulmonary fitness. The drug voxelotor raises hemoglobin in SCA. We hypothesized that voxelotor improves exercise capacity in youths with SCA. In a single-center, open-label, single-arm, longitudinal interventional pilot study (NCT04581356), SCA patients aged 12 and older, stably maintained on hydroxyurea, were treated with 1500mg voxelotor daily, and performed cardiopulmonary exercise testing before (CPET#1) and after voxelotor (CPET#2). A modified Bruce Protocol was performed on a motorized treadmill, and breath-by-breath gas exchange data were collected. Peak oxygen consumption (peak VO2 ), anaerobic threshold, O2 pulse, VE/VCO2 slope, and time exercised were compared for each participant. The primary endpoint was change in peak VO2 . Hematologic parameters were measured before each CPET. Patient Global Impression of Change (PGIC) and Clinician Global Impression of Change (CGIC) surveys were collected. Ten hemoglobin SS patients aged 12-24 completed the study. All demonstrated expected hemoglobin rise, with average +1.6g/dL (p=.003) and P50 left shift of average -11mmHg (p<.0001) with decreased oxygen off-loading at low pO2 . The change in % predicted peak VO2 from CPET#1 to CPET#2 ranged from -12.8% to +11.3%, with significant improvement of more than 5% in one subject, more than 5% decrease in five subjects, and insignificant change of less than 5% in four subjects. All 10 CGIC and seven of 10 PGIC responses were positive. In a plot study of 10 youths with SCA, voxelotor treatment did not improve peak VO2 in 9 out of 10 patients.