Comprehensive Cardiac Rehabilitation Following Acute Myocardial Infarction Improves Clinical Outcomes Regardless of Exercise Capacity.

BACKGROUND: Reduced exercise capacity is a prognostic indicator of adverse outcomes in patients with acute myocardial infarction (AMI). However, few studies have evaluated the effectiveness of comprehensive cardiac rehabilitation (CR) in this population. This study aimed to clarify the efficacy of comprehensive CR in patients with AMI and reduced exercise capacity.Methods and Results: This cohort study included 610 patients with AMI who underwent percutaneous coronary intervention. Major adverse cardiovascular events (MACE) were compared between patients who participated in comprehensive outpatient CR for 150 days (CR group; n=430) and those who did not (non-CR group; n=180). During the mean (±SD) follow-up period of 6.1±4.0 years, the CR group exhibited a lower incidence of MACE (log-rank P=0.002). Multivariable analysis revealed that Killip classification, diuretics at discharge, and participation in comprehensive CR were independently associated with MACE. The CR group was further divided into 2 groups, namely reduced exercise capacity (% predicted peak V̇O2<80%; n=241) and preserved exercise capacity (≥80%; n=147), based on the initial cardiopulmonary exercise test. Despite distinct exercise capacities, the incidence of MACE was comparable and physical parameters improved similarly after comprehensive CR in both groups. CONCLUSIONS: Comprehensive CR in patients with AMI effectively reduced the incidence of MACE regardless of initial exercise capacity. Cardiologists should actively encourage patients with low exercise capacity to participate in comprehensive CR.

Incremental Ramp Load Protocol to Assess Inspiratory Muscle Endurance in Healthy Individuals: Comparison with Incremental Step Loading Protocol.

INTRODUCTION: Protocols for obtaíníng the maxímum threshold pressure have been applied wíth límited precision to evaluate ínspiratory muscle endurance. In thís sense, new protocols are needed to allow more relíable measurements. The purpose of the present study was to compare a new incremental ramp load protocol for the evaluation of ínspíratory muscle endurance wíth the most used protocol in healthy indíviduals. METHODS: This was a prospective cross-sectional study carried out ín a síngle center. Nínety-two healthy indíviduals (43 men [22 ± 3 years] and 49 women [22 ± 3 years]) were randomly allocated to perform: (i) íncremental ramp load protocol and (íí) íncremental step loadíng protocol. The sustained pressure threshold (or maximum threshold pressure), maximum threshold pressure/dynamic strength índex ratío, time untíl task faílure, as well as dífference between the mean heart rate of the last five mínutes of baselíne and the peak heart rate of the last 30 seconds of each protocol were measured. RESULTS: Incremental ramp load protocol wíth small íncreases in the load and starting from mínímum values of strength index was able to evaluate the inspiratory muscle endurance through the maxímum threshold pressure of healthy indívíduals. CONCLUSION: The present study suggests that the íncremental ramp load protocol is able to measure maximum threshold pressure in a more thorough way, wíth less progression and greater accuracy in the load stratification compared to the límited incremental step loading protocol and with a safe and expected cardiovascular response in healthy individuals.

Changes in red blood cell parameters during incremental exercise in highly trained athletes of different sport specializations.

Background: During physical exercise, the level of hematological parameters change depending on the intensity and duration of exercise and the individual's physical fitness. Research results, based on samples taken before and after exercise, suggest that hematological parameters increase during incremental exercise. However, there is no data confirming this beyond any doubt. This study examined how red blood cell (RBC) parameters change during the same standard physical exertion in athletes representing different physiological training profiles determined by sport discipline. Methods: The study included 39 highly trained male members of national teams: 13 futsal players, 12 sprinters, and 14 triathletes. We used multiple blood sampling to determine RBC, hemoglobin (Hb), hematocrit value (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red blood cell distribution width (RDW) before, during (every 3 min), and after (5, 10, 15, 20, and 30 min) an incremental treadmill exercise test until exhaustion. Results: There were no significant exercise-induced differences in RBC parameters between athletic groups. No significant changes were recorded in RBC parameters during the low-intensity phase of exercise. RBC, Hb, and Hct increased significantly during incremental physical exercise, and rapidly returned to resting values upon test termination. Conclusions: The general pattern of exercise-induced changes in RBC parameters is universal regardless of the athlete's physiological profile. The changes in RBC parameters are proportional to the intensity of exercise during the progressive test. The increase in hemoglobin concentration associated with the intensity of exercise is most likely an adaptation to the greater demand of tissues, mainly skeletal muscles, for oxygen.

The effect of anabolic androgenic steroids on heart rate recovery index and electrocardiographic parameters in male bodybuilders.

BACKGROUND: The control of the cardiovascular system depends on the autonomic nerve system. Chronic anabolic andorogenic steroids (AAS) use causes sympathovagal imbalance and increases sympathetic nerve activity. OBJECTIVE: The reduction in heart rate from the peak exercise rate following the end of the exercise stress test is known as the heart rate recovery index (HRRI). Several methods have been utilized to assess myocardial repolarization, such as QT interval (QT), corrected QT interval (QTc), and T-wave peak-to-end interval (Tp-e interval). Based on a growing number of data a higher Tp-e/QT ratio is linked to malignant ventricular arrhythmias, and an increased Tp-e interval may correlate with the transmural dispersion of repolarization. Our hypothesis is that the use of chronic AAS was decrease HRRI during maximal exercise and increased risk of cardiac arrhythmias and sudden cardiac death. METHODS: This study included 44 male bodybuilders, with an average age of 29.7 ± 8.14 years, divided into AAS abuse [AAS users (n = 21) and AAS nonuser (n = 23)]. RESULTS: The first (p = 0.001) and second minute (p = 0.001) HRRI of the subjects with AAS users were significantly lower than those of the control group. Additionally, HRRI after the third (p = 0.004) and fifth minutes (p = 0.007) of the recovery period were significantly lower in AAS group compared with the control group. Who used AAS had significantly higher QT, QTc, Tp-e, Tp-e/QT, and Tp-e/QTc values than non-users (all p = 0.001). CONCLUSIONS: Chronic AAS use has been shown to cause sympathetic dominance, which may be a pro arrhythmic state.

Residual radiological opacities correlate with disease outcomes in ICU-treated COVID-19.

Background: Few studies consider both radiological and functional outcomes in COVID-19 survivors treated in the intensive care unit (ICU). We investigated clinical findings and pulmonary abnormalities on chest computed tomography (CT) and compared outcomes of severe versus mild-moderate acute respiratory distress syndrome (ARDS) on long-term follow-up. Methods: This longitudinal cohort study included 118 COVID-19 patients (median age, 58 years; 79% men). Thoracic CT scans were performed 4, 10, and 22 months after hospital discharge. Two independent blinded radiologists analyzed the 10 months scans and scored the radiology findings semi-quantitatively, as no/minor versus widespread opacities [low-radiology opacity grade (ROG) versus high-ROG]. ARDS severity was based on the PaO2/FiO2 ratio. The 6 min walk test (6MWT) was performed after 3 and 9 months, and lung diffusion capacity for carbon monoxide (DLCO) and lung volume measurement after 9 and 15 months. Dynamic spirometry was done at all time points. Residual symptoms and health-related quality-of-life (HRQL) were evaluated using validated questionnaires. Results: At 10 months, most patients (81/118; 69%) were classified as high-ROG, of which 70% had severe ARDS during hospitalisation; 69% of those with mild-moderate ARDS also had high-ROG. Patients with high-ROG had longer ICU stay and lower PaO2/FiO2 during hospitalisation (p < 0.01). At 9 months follow-up, patients with high-ROG had smaller lung volumes as % of predicted values [mean (±CI): 80 (77-84) vs. 93 (88-98) (p < 0.001)], lower DLCO as % of predicted values [74 (70-78) vs. 87 (82-92) (p < 0.001)], lower oxygen saturation during 6MWT (p = 0.02), and a tendency to more severe dyspnoea (p = 0.07), but no difference was found in HRQL compared with no/minor ROG (p = 0.92). A higher opacity score was related to lower DLCO at follow-up (r = -0.48, p < 0.001, Spearman rank test). Severe ARDS patients had slightly more severe fatigue at 9 months compared to mild-moderate, but no differences in dyspnoea or lung function at follow-up. Fibrotic-like changes were found in 93% of patients examined with CT scans at 2 years (55/118; 47%). Severe ARDS could predict widespread opacities (ROG > 25%) in most patients at follow-up at 10 months (AUC 0.74). Conclusion: Residual radiological abnormalities in ICU-treated COVID-19 patients, evaluated for up to 2 years, relate to persisting symptoms and impaired lung function, demanding careful follow-up regardless of ARDS severity at hospitalisation.

Accurate Prediction Equations for Ventilatory Thresholds in Cardiometabolic Disease When Gas Exchange Analysis is Unavailable: Development and Validation.

AIMS: To develop and validate equations predicting heart rate (HR) at the first and second ventilatory thresholds (VTs) and an optimized range-adjusted prescription for patients with cardiometabolic disease (CMD). To compare their performance against guideline-based exercise intensity domains. METHODS: Cross-sectional study involving 2,868 CMD patients from nine countries. HR predictive equations for first and second VTs (VT1, VT2) were developed using multivariate linear regression with 975 cycle-ergometer cardiopulmonary exercise tests (CPET). 'Adjusted' percentages of peak HR (%HRpeak) and HR reserve (%HRR) were derived from this group. External validation with 1,893 CPET (cycle-ergometer or treadmill) assessed accuracy, agreement, and reliability against guideline-based %HRpeak and %HRR prescriptions using mean absolute percentage error (MAPE), Bland-Altman analyses, intraclass correlation coefficients (ICC). RESULTS: HR predictive equations (R²: 0.77 VT1, 0.88 VT2) and adjusted %HRR (VT1: 42%, VT2: 77%) were developed. External validation demonstrated superiority over widely used guideline-directed intensity domains for %HRpeak and %HRR. The new methods showed consistent performance across both VTs with lower MAPE (VT1: 7.1%, VT2: 5.0%), 'good' ICC for VT1 (0.81, 0.82) and 'excellent' for VT2 (0.93). Guideline-based exercise intensity domains had higher MAPE (VT1: 6.8%-21.3%, VT2: 5.1%-16.7%), 'poor' to 'good' ICC for VT1, and 'poor' to 'excellent' for VT2, indicating inconsistencies related to specific VTs across guidelines. CONCLUSION: Developed and validated HR predictive equations and the optimized %HRR for CMD patients for determining VT1 and VT2 outperformed the guideline-based exercise intensity domains and showed ergometer interchangeability. They offer a superior alternative for prescribing moderate intensity exercise when CPET is unavailable.

Equations to predict heart rate at ventilatory thresholds were developed and externally validated, offering a new perspective when a cardiopulmonary exercise test is unavailable to accurately determine the aerobic exercise intensity domains. Additionally, an adjusted range for exercise intensity prescription based on the percentage of heart rate reserve (%HRR) was provided, utilizing a large sample from eight countries. The proposed equations and the range-adjusted %HRR significantly outperformed the guideline-directed methods for determining exercise intensity, exhibiting higher accuracy, agreement, and reliability. Exercise intensity prescription based on the percentage of heart rate peak showed higher errors, raising concerns about its clinical applicability. Our study may enhance the efficacy of exercise training and physical activity advice when gas exchange analysis is unavailable, potentially leading to improved clinical outcomes, even in low-resource settings. Employing these approaches in research could facilitate more tailored and consistent interventions, introducing a contemporary perspective for studies comparing exercise intensity prescriptions.

Determinants of physical quality of life in patients with chronic thromboembolic pulmonary hypertension after treatment: Insights from invasive exercise stress test.

BACKGROUND: Impaired quality of life (QoL) is prevalent among patients with chronic thromboembolic pulmonary hypertension (CTEPH) despite improved survival due to medical advances. We clarified the physical QoL of patients with CTEPH with mildly elevated pulmonary hemodynamics and evaluated its determinants using a database of patients with CTEPH evaluated for hemodynamics during exercise. METHODS: The QoL was measured in 144 patients with CTEPH (age, 66 (58-73) years; men/women, 48/96) with mildly elevated mean pulmonary artery pressure (< 30 mmHg) at rest after treatment with balloon pulmonary angioplasty and/or pulmonary endarterectomy using the Short-Form 36 (SF-36) questionnaire. The enrolled patients were divided into two groups: physical component summary (PCS) scores in the SF-36 over 50 as PCS-good and those under 50 as PCS-poor. RESULTS: The median PCS in SF-36 score was 43.4 (IQR 32.4-49.5) points. The PCS-poor group (n = 110) was older and had lower exercise capacity and SaO2 during exercise. PCS scores were correlated with 6-minute walk distance (rs = 0.40, p < 0.001), quadriceps strength (rs = 0.34, p < 0.001), peak VO2 (rs = 0.31, p < 0.001), SaO2 at rest (rs = 0.35, p < 0.001) and peak exercise (rs = 0.33, p < 0.001), home oxygen therapy usage (rs = -0.28, p = 0.001), and pulmonary vascular resistance at peak exercise (rs = -0.26, p = 0.002). CONCLUSIONS: The impairment of physical QoL was common in patients with CTEPH with improved hemodynamics; exercise capacity, hypoxemia, and hemodynamic status during exercise were related to the physical QoL.

Exercise limitation in hypertrophic cardiomyopathy: combined stress echocardiography and cardiopulmonary exercise test.

AIMS: The study aims to investigate exercise-limiting factors in hypertrophic cardiomyopathy (HCM) using combined stress echocardiography and cardiopulmonary exercise test. METHODS AND RESULTS: A symptom-limited ramp bicycle exercise test was performed in the semi-supine position on a tilting dedicated ergometer. Echocardiographic images were obtained concurrently with gas exchange measurements along predefined stages of exercise. Oxygen extraction was calculated using the Fick equation at each activity level. Thirty-six HCM patients (mean age 67 ± 6 years, 72% men, 18 obstructive HCM) were compared with age and sex-matched 29 controls. At rest, compared with controls, E/E' ratio (6.26 ± 2.3 vs. 14 ± 2.5, P < 0.001) and systolic pulmonary artery pressures (SPAP) (22.6 ± 3.4 vs. 34 ± 6.2 mmHg, P = 0.023) were increased. Along with the stages of exercise (unloaded; anaerobic threshold; peak), diastolic function worsened (E/e' 8.9 ± 2.6 vs. 13.8 ± 3.6 P = 0.011; 9.4 ± 2.3 vs. 18.6 ± 3.3 P = 0.001; 8.7 ± 1.9 vs. 21.5 ± 4, P < 0.001), SPAP increased (23 ± 2.7 vs. 33 ± 4.4, P = 0.013; 26 ± 3.2 vs. 40 ± 2.9, P < 0.001; 26 ± 3.5 vs. 45 ± 7 mmHg, P < 0.001), and oxygen consumption (6.6 ± 1.7 vs. 6.8 ± 1.6, P = 0.86; 18.1 ± 2.2 vs. 14.6 ± 1.5, P = 0.008; 20.3 ± 3 vs. 15.1 ± 2.1 mL/kg/min, P = 0.01) was reduced. Oxygen pulse was blunted (6.3 ± 1.8 vs. 6.2 ± 1.9, P = 0.79; 10 ± 2.1 vs. 8.8 ± 1.6, P = 0.063; 12.2 ± 2 vs. 8.2 ± 2.3 mL/beat, P = 0.002) due to an insufficient increase in both stroke volume (92.3 ± 17 vs. 77.3 ± 14.5 P = 0.021; 101 ± 19.1 vs. 87.3 ± 15.7 P = 0.06; 96.5 ± 12.2 vs. 83.6 ± 16.1 mL, P = 0.034) and oxygen extraction (0.07 ± 0.03 vs. 0.07 ± 0.02, P = 0.47; 0.13 ± 0.02 vs. 0.10 ± 0.03, P = 0.013; 0.13 ± 0.03 vs. 0.11 ± 0.03, P = 0.03). Diastolic dysfunction, elevated SPAP, and the presence of atrial fibrillation were associated with reduced exercise capacity. CONCLUSIONS: Both central and peripheral cardiovascular limitations are involved in exercise intolerance in HCM. Diastolic dysfunction seems to be the main driver for this limitation.

Novel wireless laser doppler flowmeter-based investigation of earlobe vascular dynamics in cardiopulmonary exercise testing.

[Purpose] A new wireless laser Doppler blood flowmeter has facilitated easier, more stable measurement of skin perfusion during exercise. However, earlobe blood flow during the cardiopulmonary exercise test remains unascertained. This study aimed to clarify the characteristics of earlobe blood flow during incremental exercise load in healthy individuals. [Participants and Methods] Among 25 healthy males (age 23.6 ± 2.5 years), cycle ergometer-based symptom-limited cardiopulmonary exercise test, after 4 minutes of rest, was conducted with a 4-minute 20W warm-up and a continuous 2W-increase in the work rate every 6 seconds; earlobe blood flow was measured using a wireless laser Doppler blood flowmeter. [Results] Compared with that at rest, earlobe blood flow increased significantly from 50% of exercise peak intensity to a maximum of 1.7 times, but decreased immediately after exercise. The earlobe blood flow %change did not significantly correlate with hemodynamic parameters and its inflection point 36.4% Loadpeak was significantly lower than the anaerobic metabolic threshold 58.1% Loadpeak. [Conclusion] In healthy participants, earlobe blood flow during cardiopulmonary exercise test increased gradually with low-intensity exercise from approximately 1.5 times the resting rate and approached the anaerobic metabolic threshold with a maximum of 1.7 times the resting earlobe blood flow, but decreased quickly after exercise.

[National Survey on the Activity of Lung Function Laboratories. Effects During the SARS-COV-2 Pandemic]. / Encuesta sobre la actividad de los laboratorios de función pulmonar. Efectos durante la pandemia por SARS-CoV-2.

Introduction: Following the SARS-CoV-2 pandemic in March 2020, pulmonary function testing (PFT) laboratories underwent a transformation, with a reduction in the number of tests or closure in some cases. The aim of this work was to know the activity of PFT in Spain and the modification of this activity due to the pandemic. Material and methods: A protocolised survey was carried out to members of the PFT laboratories through the Spanish Society of Pneumology and Thoracic Surgery (SEPAR). Results: Thirty-nine hospitals in Spain responded. The pulmonary function tests most frequently performed in the PFT laboratories were forced spirometry with bronchodilator test (100%), body plethysmography (97.4%), CO transfer capacity (97.4%), respiratory muscle strength measured in the mouth (97.4%), 6-minute walking test (94.7%), measurement of exhaled fraction of nitric oxide (92.3%) and incremental exercise test (71.8%).The pandemic led to a significant decrease in the number of tests (35.4%) during 2020 with subsequent recovery in 2021, without reaching pre-pandemic values.The most important changes were increased examination times, working with personal protective equipment and ventilation of the rooms. The performance of the nasopharyngeal swab for SARS-CoV2 testing prior to the tests was not homogeneous in the PFT laboratories. Conclusions: Most hospitals are sufficiently equipped to perform the most common pulmonary function tests. The pandemic resulted in a loss of activity in all hospitals.

Cardiorespiratory Fitness Benefits of Long-Term Maintenance-Phase Cardiac Rehabilitation in Males and Females: A Retrospective Cohort Study.

Purpose: This study investigated if associations exist between enrolment delay and VO2peak over five years of maintenance-phase cardiac rehabilitation (CR) in males and females. Method: Data were extracted from the records of participants who had enrolled for ≥ 1 year in CR and completed ≥ 2 cardiopulmonary exercise tests. Mixed model analyses examined VO2peak trajectories for up to five years of enrolment. Interactions between enrolment delay × enrolment duration, baseline age × enrolment duration, and baseline VO2peak × enrolment duration were explored for inclusion in the model. Results: The charts of 151 males (aged 63.9 ± 9.4 y) and 32 females (aged 65.3 ± 9.0 y) were included in the analyses. The enrolment delay following a cardiovascular event was 1.8 ± 3.0 years for males and 1.3 ± 1.7 years for females. No associations were found between enrolment delay × enrolment duration on VO2peak in males (ß[SEj, 0.07[0.05]; 95% CI -0.02, 0.16, p = 0.12) or in females (ß[SE], 0.07[0.13j; 95% CI -0.18, 0.33, p = 0.57), but predicted trajectories suggest clinically significantly improvements in VO2 peak (range, 1.3 to 1.6 mL/kg/min). Conclusions: Early enrolment in CR is recommended and encouraged, but the benefits of long-term CR are possible despite delays.

Objectif: étudier les associations éventuelles entre le retard d'inscription et la consommation maximale d'oxygène (VO2 max) pendant une phase d'entretien de cinq ans de la réadaptation cardiaque (RC) chez des hommes et des femmes. Méthodologie: données extraites des dossiers des participants inscrits en RC pendant au moins un an et qui ont effectué au moins deux épreuves d'effort cardiorespiratoire. Par des analyses en modèle mixte, les chercheurs ont examiné les trajectoires de VO2 max pendant une période d'inscription maximale de cinq ans. Ils ont exploré les interactions entre le retard d'inscription × la durée d'inscription, entre l'âge au départ × la durée d'inscription et entre la VO2 max au départ × la durée d'inscription pour les inclure dans le modèle. Résultats: les dossiers de 151 hommes (de 63,9 ± 9,4 ans) et de 32 femmes (de 65,3 ± 9,0 ans) ont été inclus dans les analyses. Après un événement cardiovasculaire, les hommes présentaient un retard d'inscription de 1,8 ± 3,0 ans et les femmes, de 1,3 ± 1,7 an. Les chercheurs n'ont constaté aucune association entre le retard d'inscription × la durée d'inscription et la VO2 max chez les hommes (ß[ET], 0,7[0,05]; IC à 95 % −0,02, 0,16, p = 0,12) ni chez les femmes (ß[ET], 0,07[0,13]; IC à 95 % −0,18, 0,33, p = 0,57), mais les trajectoires anticipées laissent supposer des améliorations cliniquement significatives de la VO2 max (plage de 1,3 à 1,6 mL/kg/min). Conclusions: il est recommandé et encouragé de s'inscrire rapidement en RC, mais la RC à long terme peut comporter des avantages malgré les retards d'inscription.

Chronotropic Incompetence in Parkinson's Disease: A Possible Marker of Severe Disease Phenotype?

Autonomic dysfunction is a prevalent feature of Parkinson's disease (PD), mediated by disease involvement of the autonomic nervous system. Chronotropic incompetence (CI) refers to inadequate increase of heart rate in response to elevated metabolic demand, partly dependent on postganglionic sympathetic tone. In a retrospective study, PD patients with/without CI were identified. We show that PD with CI was associated with a higher levodopa equivalent daily dose and Hoehn and Yahr stage, 5±2 years after motor onset. Our data support a putative role of CI as a clinical marker of a more severe disease phenotype, possibly reflecting more widespread alpha-synuclein pathology.

Integrative Assessment of Cardiopulmonary Fitness Using Cardiopulmonary Exercise Test With Supine Bicycle Echocardiography in Patients Presenting Dyspnea.

BACKGROUND: Cardiopulmonary exercise test (CPET) with supine bicycle echocardiography (SBE) enables comprehensive physiologic assessment during exercise. We characterized cardiopulmonary fitness by integrating CPET-SBE parameters and evaluated its prognostic value in patients presenting with dyspnea. METHODS AND RESULTS: We retrospectively reviewed 473 consecutive patients who underwent CPET-SBE for dyspnea evaluation. A dimensionality reduction process was applied, transforming 24 clinical and CPET-SBE parameters into a 2-dimensional feature map, followed by patient clustering based on the data distribution. Clinical and exercise features were compared among the clusters in addition to the 5-year risk of clinical outcome (a composite of cardiovascular death and heart failure hospitalization). Maximum exercise effort (R >1) was achieved in 95% of cases. Through dimensionality reduction, 3 patient clusters were derived: Group 1 (n=157), 2 (n=104), and 3 (n=212). Median age and female proportion increased from Group 1 to 2, and 3, although resting echocardiography parameters showed no significant abnormalities among the groups. There was a worsening trend in the exercise response from Group 1 to 2 and 3, including left ventricular diastolic function, oxygen consumption, and ventilatory efficiency. During follow-up (median 6.0 [1.6-10.4] years), clinical outcome increased from Group 1 to 2 and 3 (5-year rate 3.7% versus 7.0% versus 13.0%, respectively; log-rank P=0.02), with higher risk in Group 2 (hazard ratio, 1.94 [95% CI, 0.52-7.22]) and Group 3 (3.92 [1.34-11.42]) compared with Group 1. CONCLUSIONS: Comprehensive evaluation using CPET-SBE can reveal distinct characteristics of cardiopulmonary fitness in patients presenting with dyspnea, potentially enhancing outcome prediction.

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 deterioration is 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). 32 patients 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/VCO2 slope. 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 > 101 ml/m2 and an end-systolic volume index > 47 ml/m2 discriminated 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.

Acute and subacute effects of strenuous exercise on platelet aggregation, coagulation and fibrinolysis in patients with stable coronary artery disease.

INTRODUCTION: Strenuous exercise may occasionally cause coronary thrombosis with myocardial infarction and sudden cardiac death. MATERIALS AND METHODS: Patients with stable coronary artery disease (CAD) (n = 164) and healthy individuals (n = 25) performed strenuous exercise on a bicycle ergometer. Blood was drawn at baseline, immediately after exercise and 2 h later. Platelet aggregation was measured with Multiplate® Analyzer. Thrombin generation was determined using a thrombogram and by measuring prothrombin fragment 1 + 2 (F1 + 2). A clot lysis assay was used to investigate fibrinolysis. RESULTS: From baseline to immediately after exercise, thrombin receptor activating peptide (TRAP)-induced platelet aggregation increased in CAD patients (Δ77 AU × min, 95 % confidence interval (CI): 46;107) and in healthy individuals (Δ153 AU × min, 95%CI: 75;232). Endogenous thrombin potential (ETP) was unaffected by exercise, whilst F1 + 2 increased (Δ17%, 95%CI: 11;24) in CAD patients. Fibrin clot lysis time increased by 9 % (95%CI: 1-17) in CAD patients and by 26 % (95%CI: 8;45) in healthy individuals. When comparing baseline to 2 h post-exercise, TRAP-induced platelet aggregation remained slightly elevated in both CAD patients (Δ53 AU × min, 95%CI: 22;84) and healthy individuals (Δ140 AU × min, 95%CI: 62;219). In contrast, ETP and F1 + 2 decreased in CAD patients (Δ-6 %, 95%CI: -10;-1 and Δ-8 %, 95%CI: -14;-2). Moreover, clot lysis time decreased (Δ-19 %, 95%CI: -27;-11) in patients with CAD and returned to baseline in healthy individuals. All p-values were <0.05. CONCLUSIONS: Platelet aggregation and F1 + 2 were substantially elevated immediately after exercise in CAD patients, indicating a pro-thrombotic state. After 2 h of recovery, they exhibited a markedly increase in fibrinolysis. Similar results were observed in healthy individuals.

Assessing a GPS-Based 6-Minute Walk Test for People With Persistent Pain: Validation Study.

BACKGROUND: The 6-minute walk test (6MWT) is a commonly used method to assess the exercise capacity of people with many health conditions, including persistent pain. However, it is conventionally performed with in-person supervision in a hospital or clinic, therefore requiring staff resources. It may also be difficult when in-person supervision is unavailable, such as during the COVID-19 pandemic, or when the person is geographically remote. A potential solution to these issues could be to use GPS to measure walking distance. OBJECTIVE: The primary aim of this study was to assess the validity of a GPS-based smartphone app to measure walking distance as an alternative to the conventional 6MWT in a population with persistent pain. The secondary aim of this study was to estimate the difference between the pain evoked by the 2 test methods. METHODS: People with persistent pain (N=36) were recruited to complete a conventional 6MWT on a 30-m shuttle track and a 6MWT assessed by a smartphone app using GPS, performed on outdoor walking circuits. Tests were performed in random order, separated by a 15-minute rest. The 95% limits of agreement were calculated using the Bland-Altman method, with a specified maximum allowable difference of 100 m. Pain was assessed using an 11-point numerical rating scale before and after each walk test. RESULTS: The mean 6-minute walk distance measured by the GPS-based smartphone app was 13.2 (SD 46; 95% CI -2.7 to 29.1) m higher than that assessed in the conventional manner. The 95% limits of agreement were 103.9 (95% CI 87.4-134.1) m and -77.6 (95% CI -107.7 to -61) m, which exceeded the maximum allowable difference. Pain increased in the conventional walk test by 1.1 (SD 1.0) points, whereas pain increased in the app test by 0.8 (SD 1.4) points. CONCLUSIONS: In individuals with persistent pain, the 2 methods of assessing the 6MWT may not be interchangeable due to limited validity. Potential reasons for the differences between the 2 methods might be attributed to the variation in track layout (shuttle track vs continuous circuit); poor GPS accuracy; deviations from the 30-m shuttle track; human variability in walking speed; and the potential impact of a first test on the second test due to fatigue, pain provocation, or a learning effect. Future research is needed to improve the accuracy of the GPS-based approach. Despite its limitations, the GPS-based 6MWT may still have value as a tool for remote monitoring that could allow individuals with persistent pain to self-administer frequent assessments of their functional capacity in their home environment.

Mechanisms and consequences of excess exercise ventilation in fibrosing interstitial lung disease.

The causes and consequences of excess exercise ventilation (EEV) in patients with fibrosing interstitial lung disease (f-ILD) were explored. Twenty-eight adults with f-ILD and 13 controls performed an incremental cardiopulmonary exercise test. EEV was defined as ventilation-carbon dioxide output (⩒E-⩒CO2) slope ≥36 L/L. Patients showed lower pulmonary function and exercise capacity compared to controls. Lower DLCO was related to higher ⩒E-⩒CO2 slope in patients (P<0.05). 13/28 patients (46.4%) showed EEV, reporting higher dyspnea scores (P=0.033). Patients with EEV showed a higher dead space (VD)/tidal volume (VT) ratio while O2 saturation dropped to a greater extent during exercise compared to those without EEV. Higher breathing frequency and VT/inspiratory capacity ratio were observed during exercise in the former group (P<0.05). An exaggerated ventilatory response to exercise in patients with f-ILD is associated with a blunted decrease in the wasted ventilation in the physiological dead space and greater hypoxemia, prompting higher inspiratory constraints and breathlessness.

Cardiopulmonary exercise test to detect cardiac dysfunction from pulmonary vascular disease.

BACKGROUND: Cardiac dysfunction from pulmonary vascular disease causes characteristic findings on cardiopulmonary exercise testing (CPET). We tested the accuracy of CPET for detecting inadequate stroke volume (SV) augmentation during exercise, a pivotal manifestation of cardiac limitation in patients with pulmonary vascular disease. METHODS: We reviewed patients with suspected pulmonary vascular disease in whom CPET and right heart catheterization (RHC) measurements were taken at rest and at anaerobic threshold (AT). We correlated CPET-determined O2·pulseAT/O2·pulserest with RHC-determined SVAT/SVrest. We evaluated the sensitivity and specificity of O2·pulseAT/O2·pulserest to detect SVAT/SVrest below the lower limit of normal (LLN). For comparison, we performed similar analyses comparing echocardiographically-measured peak tricuspid regurgitant velocity (TRVpeak) with SVAT/SVrest. RESULTS: From July 2018 through February 2023, 83 simultaneous RHC and CPET were performed. Thirty-six studies measured O2·pulse and SV at rest and at AT. O2·pulseAT/O2·pulserest correlated highly with SVAT/SVrest (r = 0.72, 95% CI 0.52, 0.85; p < 0.0001), whereas TRVpeak did not (r = -0.09, 95% CI -0.47, 0.33; p = 0.69). The AUROC to detect SVAT/SVrest below the LLN was significantly higher for O2·pulseAT/O2·pulserest (0.92, SE 0.04; p = 0.0002) than for TRVpeak (0.69, SE 0.10; p = 0.12). O2·pulseAT/O2·pulserest of less than 2.6 was 92.6% sensitive (95% CI 76.6%, 98.7%) and 66.7% specific (95% CI 35.2%, 87.9%) for deficient SVAT/SVrest. CONCLUSIONS: CPET detected deficient SV augmentation more accurately than echocardiography. CPET-determined O2·pulseAT/O2·pulserest may have a prominent role for noninvasive screening of patients at risk for pulmonary vascular disease, such as patients with persistent dyspnea after pulmonary embolism.

Comparison of the muscle oxygenation during submaximal and maximal exercise tests in patients post-coronavirus disease 2019 syndrome with pulmonary involvement.

INTRODUCTION: Pulmonary involvement is prevalent in patients with coronavirus disease 2019 (COVID-19). Arterial hypoxemia may reduce oxygen transferred to the skeletal muscles, possibly leading to impaired exercise capacity. Oxygen uptake may vary depending on the increased oxygen demand of the muscles during submaximal and maximal exercise. OBJECTIVE: This study aimed to compare muscle oxygenation during submaximal and maximal exercise tests in patients with post-COVID-19 syndrome with pulmonary involvement. METHODS: Thirty-nine patients were included. Pulmonary function (spirometry), peripheral muscle strength (dynamometer), quadriceps femoris (QF) muscle oxygenation (Moxy® device), and submaximal exercise capacity (six-minute walk test (6-MWT)) were tested on the first day, maximal exercise capacity (cardiopulmonary exercise test (CPET)) was tested on the second day. Physical activity level was evaluated using an activity monitor worn for five consecutive days. Cardiopulmonary responses and muscle oxygenation were compared during 6-MWT and CPET. RESULTS: Patients' minimum and recovery muscle oxygen saturation were significantly decreased; maximum total hemoglobin increased, heart rate, blood pressure, breathing frequency, dyspnea, fatigue, and leg fatigue at the end-of-test and recovery increased in CPET compared to 6-MWT (p < .050). Peak oxygen consumption (VO2peak) was 18.15 ± 4.75 ml/min/kg, VO2peak; percent predicted < 80% was measured in 51.28% patients. Six-MWT distance and QF muscle strength were less than 80% predicted in 58.9% and 76.9% patients, respectively. CONCLUSIONS: In patients with post-COVID-19 syndrome with pulmonary involvement, muscle deoxygenation of QF is greater during maximal exercise than during submaximal exercise. Specifically, patients with lung impairment should be evaluated for deoxygenation and should be taken into consideration during pulmonary rehabilitation.