Beltrame T, Gois MO, Hoffmann U, Koschate J, Hughson RL, Frade MCM, Linares SN, Torres RDS, Catai AM

J Appl Physiol (1985). 2020 Jul 30. doi: 10.1152/japplphysiol.00310.2020. Online ahead of print.

Efforts to better understand cardiorespiratory health are relevant for the future development of optimized physical activity programs. We aimed to explore the impact of the signal quality on the expected associations between the ability of the aerobic system in supplying energy as fast as possible during moderate exercise transitions with its maximum capacity to supply energy during maximal exertion. It was hypothesized that a slower aerobic system response during moderate exercise transitions is associated with a lower maximal aerobic power; however, this relationship relies on the quality of the oxygen uptake dataset.
Forty-three apparently healthy participants performed a moderate constant work rate (CWR) followed by a pseudorandom binary sequence (PRBS) exercise protocol on a cycle ergometer. Participants also performed a maximum incremental cardiopulmonary exercise testing (CPET). The maximal aerobic power was evaluated by the peak oxygen uptake during the CPET and the aerobic fitness was estimated from different approaches for oxygen uptake dynamics analysis during the CWR and PRBS protocols at different levels of signal-to-noise ratio. The product moment correlation coefficient was used to evaluate the correlation level between variables. Aerobic fitness was correlated with maximum aerobic power, but this correlation increased as a function of the signal-to-noise ratio.
Aerobic fitness is related to maximal aerobic power; however, this association appeared to be highly dependent on the data quality and analysis for aerobic fitness evaluation. Our results show that simpler moderate exercise protocols might be as good as maximal exertion exercise protocols to obtain indexes related to cardiorespiratory health.

Gulsin GS; Henson J; Brady EM; Sargeant JA; Wilmot EG; Athithan L; Htike ZZ; Marsh AM; Biglands JD; Kellman P; Khunti K; Webb D; Davies MJ; Yates T; McCann GP;

Diabetes care [Diabetes Care] 2020 Jul 17. Date of Electronic Publication: 2020 Jul 17.

Objective: To assess the relationship between subclinical cardiac dysfunction and aerobic exercise capacity (peak VO ₂ ) in adults with type 2 diabetes (T2D), a group at high risk of developing heart failure.
Research Design and Methods: Cross-sectional study. We prospectively enrolled a multiethnic cohort of asymptomatic adults with T2D and no history, signs, or symptoms of cardiovascular disease. Age-, sex-, and ethnicity-matched control subjects were recruited for comparison. Participants underwent bioanthropometric profiling, cardiopulmonary exercise testing, and cardiovascular magnetic resonance with adenosine stress perfusion imaging. Multivariable linear regression analysis was undertaken to identify independent associations between measures of cardiovascular structure and function and peak VO ₂ .
Results: A total of 247 adults with T2D (aged 51.8 ± 11.9 years, 55% males, 37% black or south Asian ethnicity, HbA _1c 7.4 ± 1.1% [57 ± 12 mmol/mol], and duration of diabetes 61 [32-120] months) and 78 control subjects were included. Subjects with T2D had increased concentric left ventricular remodelling, reduced myocardial perfusion reserve (MPR), and markedly lower aerobic exercise capacity (peak VO ₂ 18.0 ± 6.6 vs. 27.8 ± 9.0 mL/kg/min; P < 0.001) compared with control subjects. In a multivariable linear regression model containing age, sex, ethnicity, smoking status, and systolic blood pressure, only MPR (β = 0.822; P = 0.006) and left ventricular diastolic filling pressure (E/e’) (β = -0.388; P = 0.001) were independently associated with peak VO ₂ in subjects with T2D.
Conclusions: In a multiethnic cohort of asymptomatic people with T2D, MPR and diastolic function are key determinants of aerobic exercise capacity, independent of age, sex, ethnicity, smoking status, or blood pressure

Riedel B; Li MH; Lee CHA; Ismail H; Cuthbertson BH; Wijeysundera DN; Ho KM;

British journal of anaesthesia [Br J Anaesth] 2020 Jul 17. Date of Electronic Publication: 2020 Jul 17.

Background: Accurate assessment of functional capacity, a predictor of postoperative morbidity and mortality, is essential to improving surgical planning and outcomes. We assessed if all 12 items of the Duke Activity Status Index (DASI) were equally important in reflecting exercise capacity.
Methods: In this secondary cross-sectional analysis of the international, multicentre Measurement of Exercise Tolerance before Surgery (METS) study, we assessed cardiopulmonary exercise testing and DASI data from 1455 participants. Multivariable regression analyses were used to revise the DASI model in predicting an anaerobic threshold (AT) >11 ml kg ^-1 min ^-1 and peak oxygen consumption (VO ₂ peak) >16 ml kg ^-1 min ^-1 , cut-points that represent a reduced risk of postoperative complications.
Results: Five questions were identified to have dominance in predicting AT>11 ml kg ^-1 min ^-1 and VO ₂ peak>16 ml.kg ^-1 min ^-1 . These items were included in the M-DASI-5Q and retained utility in predicting AT>11 ml.kg ^-1 .min ^-1 (area under the receiver-operating-characteristic [AUROC]-AT: M-DASI-5Q=0.67 vs original 12-question DASI=0.66) and VO ₂ peak (AUROC-VO2 peak: M-DASI-5Q 0.73 vs original 12-question DASI 0.71). Conversely, in a sensitivity analysis we removed one potentially sensitive question related to the ability to have sexual relations, and the ability of the remaining four questions (M-DASI-4Q) to predict an adequate functional threshold remained no worse than the original 12-question DASI model. Adding a dynamic component to the M-DASI-4Q by assessing the chronotropic response to exercise improved its ability to discriminate between those with VO ₂ peak>16 ml.kg ^-1 .min ^-1 and VO ₂ peak<16 ml.kg ^-1 .min ^-1 .
Conclusions: The M-DASI provides a simple screening tool for further preoperative evaluation, including with cardiopulmonary exercise testing, to guide perioperative management.

Schoenfeld J; Schindler Haller B; Holdenrieder S; Nieman DC; Halle M; La Gerche A; Scherr J;

BMJ open sport & exercise medicine [BMJ Open Sport Exerc Med] 2020 Jul 19; Vol. 6 (1), pp. e000786. Date of Electronic Publication: 2020 Jul 19 (Print Publication: 2020).

Introduction: Prolonged strenuous exercise training may result in structural, functional and electrical cardiac remodelling, as well as vascular and myocardial injuries. However, the extent to which high-volume, intense exercise is associated with arrhythmias, myocardial fibrosis, coronary heart disease and pathological alterations of the vasculature remains unknown. In addition, there is no clear consensus on the clinical significance of these exercise-induced changes. Previous studies typically used cross-sectional designs and examined exercise-induced cardiovascular changes in small cohorts of athletes for up to 3-7 days of recovery. Long-term longitudinal studies investigating cardiovascular changes induced by prolonged strenuous exercise in large cohorts of athletes are needed to improve scientific understanding in this area.
Methods and Analysis: In this prospective observational monocenter study, 277 participants of the Beer, Marathon, Genetics, Inflammation and the Cardiovascular System (Be-MaGIC) study (ClinicalTrials.gov: NCT00933218) will be invited to participate in this 10-year follow-up study. A minimum target sample size of 130 participants will be included in the study. Participating athletes will be examined via the following: anthropometry, resting electrocardiography and echocardiography, blood sampling, retinal vessel diameters, carotid sonography and cardiopulmonary exercise testing, including exercise electrocardiography.
Discussion: This longitudinal study will provide comprehensive data on physiological changes in the cardiovascular system and the development of pathologies after a 10-year period of prolonged and strenuous endurance exercise. Since the participants will have engaged in a wide range of training loads and competitive race events, this study will provide useful risk factor determinants and training load cut-off values. The primary endpoint is the association between the exercise-induced increase in cardiac troponin during the Munich marathon 2009 and the decline in right ventricular ejection fraction over the next 10 years.
Trial Registration Number: NCT04166903.

Avesani M;Borrelli N; Krupickova S;Sabatino J; Donne GD; Ibrahim A; Piccinelli E; Josen M; Michielon G; Fraisse A; Iliceto S; Di Salvo G;

International journal of cardiology [Int J Cardiol] 2020 Jul 20. Date of Electronic Publication: 2020 Jul 20.

Background: Pulmonary regurgitation (PR) and right ventricular (RV) dilatation and disfunction are common in patients with repaired Tetralogy of Fallot (r-TOF).
Aims: To compare Echo data with the gold standard CMR in a paediatric population of r-TOF with significant PR, to assess the reliability of standard and advanced echo parameters. In addition, to evaluate their correlation with peak oxygen consumption (VO ₂ ).
Methods and Results: All patients underwent standard echo-Doppler study, speckle tracking analysis, and CMR to assess PR and RV size and function. Thirty-six patients underwent also cardiopulmonary exercise test. Fourty-six patients (aged 13.7 ± 3.0) were included. Echo derived RV areas correlated with CMR RV volumes (p < .0001, r = 0.72). RV end-diastolic area > 21.9 cm ² /m ² had a good sensitivity (83.3%) and specificity (73.5%) to identify a RV end-diastolic volume ≥ 150 ml/m ² . RVEF was preserved in all patients, while TAPSE was reduced in 78.2% and RVGLS in 60.8%. Flow-reversal in pulmonary branches showed a sensitivity of 95.8% and a specificity of 59.1% to identify CMR pulmonary regurgitant fraction (RF) ≥ 35%. None of the CMR parameters correlated with peak VO ₂ . Among the Echo data only right atrial strain (RAS) correlated with peak VO _2.
CONCLUSION: In children, flow-reversal in pulmonary branches identifies hemodynamically significant RF with a good sensitivity but poor specificity. RV area by echocardiogram is a valid first-line parameter to screen RV dilation. RV longitudinal systolic dysfunction coexists with a still preserved EF. RAS correlates strongly with peak VO ₂ and should be added in their follow up.

Burstein DS, Mcbride MG, Rossano JW, O’Connor MJ, Lin KY, Mascio CE(1), White R, Iacobellis K, Rosenthal T(1), Paridon SM.

ASAIO J. 2020 Jul 17. doi: 10.1097/MAT.0000000000001231. Online ahead of print.

Exercise rehabilitation during pediatric ventricular assist device (VAD) support aims to improve musculoskeletal strengthening while awaiting heart transplantation (HT). This study aimed to determine whether increasing VAD pump speed during exercise testing and training improves exercise capacity.
A single-center cohort study was performed comparing changes in exercise capacity on serial cardiopulmonary exercise testing (CPET) after exercise training at a fixed VAD pump speed (historical cohort from 2014 to 2017) compared with a prospective cohort (2017-2019) who underwent increasing pump speed during exercise training. All children were supported with intracorporeal continuous-flow VAD. Four subjects (13 ± 2.8 years) were included in the historical cohort, and 6 subjects (14 ± 1.7 years) were enrolled in the prospective cohort. Ninety percent had dilated cardiomyopathy, and one had single ventricle Fontan physiology. Baseline maximal oxygen consumption (VO2) was 19 ± 6.3 ml/kg/min.
After exercise training with increased pump speed, there was substantial improvement in aerobic capacity (maximal VO2 increased 42% vs. decreased 3%, respectively) and working capacity (maximal work increased 49% vs. 13%, respectively) compared with fixed pump speed. There were no adverse events reported in either the fixed or increased pump speed cohorts. Increasing VAD pump speed during exercise training results in substantial improvement in both physical working and aerobic capacity compared a fixed pump speed in children on VAD support regardless of single or biventricular ventricle physiology. Further study of a larger cohort is needed to validate these findings to improve the approach to pediatric cardiac rehabilitation in this population.

Raghuveer, G. Hartz, J. Lubans, D. R. Takken, T. Wiltz, J. L. Mietus-Snyder, M. Perak, A. M. Baker-Smith, C. Pietris, N. Edwards, N. M.

Circulation. 2020:CIR0000000000000866.

Cardiorespiratory fitness (CRF) refers to the capacity of the circulatory and respiratory systems to supply oxygen to skeletal muscle mitochondria for energy production needed during physical activity. CRF is an important marker of physical and mental health and academic achievement in youth. However, only 40% of US youth are currently believed to have healthy CRF. In this statement, we review the physiological principles that determine CRF, the tools that are available to assess CRF, the modifiable and nonmodifiable factors influencing CRF, the association of CRF with markers of health in otherwise healthy youth, and the temporal trends in CRF both in the United States and internationally. Development of a cost-effective CRF measurement process that could readily be incorporated into office visits and in field settings to screen all youth periodically could help identify those at increased risk.

Fletcher HV; Pan Cho PS; Lee Loong S; Estrada-Petrocelli L; Patel AS; Birring SS; Lee KK;

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine [J Clin Sleep Med] 2020 Jul 14. Date of Electronic Publication: 2020 Jul 14.

Study Objectives: Exercise capacity is impaired in obstructive sleep apnea (OSA). There are conflicting reports on the effect of CPAP on maximal exercise capacity. The objective of this review was to determine if there is a change in exercise capacity and anaerobic threshold following continuous positive airway pressure (CPAP) treatment in OSA patients.
Methods: We conducted a systematic review and meta-analyses to summarize the changes in peak rate of oxygen uptake (V̇O₂peak) or maximum rate of oxygen uptake (V̇O₂max) and anaerobic threshold (AT) during cardiopulmonary exercise testing following CPAP intervention in patients with OSA. A systematic literature review was conducted to identify published literature on markers of V̇O₂ peak, V̇O₂ max and AT pre versus post CPAP using a web-based literature search of PubMed/MEDLINE, Embase, CINAHL and Cochrane review (CENTRAL) databases. Two independent reviewers screened the articles for data extraction and analysis.
Results: The total search of all the databases returned 470 relevant citations. Following application of eligibility criteria, six studies were included in the final meta-analysis for V̇O₂ peak, two studies for V̇O₂ max, and five studies for AT. The meta-analysis showed a mean net difference in V̇O₂ peak between pre and post CPAP of 2.69 mL·kg ^-1 ·min ^-1 , p=0.02, favoring the treatment with CPAP. There was no difference in V̇O₂ max or AT with CPAP treatment (mean net difference 0.66 mL·kg ^-1 ·min ^-1 (0.78) and -144.98 mL·min ^-1 (p=0.20) respectively).
Conclusions: There is a paucity of high-quality studies investigating the effect of CPAP on exercise capacity. Our meta-analysis shows that V̇O₂ peak increases following CPAP treatment in patients with OSA, but we did not observe any change in V̇O₂ max or AT, Our findings should be considered preliminary and we recommend further randomized controlled trials to confirm our findings and to clarify the V̇O₂ adaptations with CPAP therapy.

Huang SC; Hsu CC; Fu TC; Chen CP; Liao MF; Hsu YH; Wang JS;

Medicine [Medicine (Baltimore)] 2020 Jul 10; Vol. 99 (28), pp. e21058.Publication Type:

A method to perform exercise testing for patients with hemiplegia is unavailable though over half of them have cardio-pulmonary disorders. We aimed to assess the reliability and validity of using a stepper in cardiopulmonary exercise testing (CPET) in this population. 14 stroke patients with hemiplegia who failed to ride the stationary bike were included. Exclusion criteria included manual muscle strength ≦1 in the lower extremity, and conventional contraindications of CPET. They underwent CPET twice by using a stepper to evaluate test-retest reliability and validity. Additionally, 10 healthy participants underwent CPET twice on the cycle ergometer and stepper respectively.In the test-retest, the ratio of two-time difference to mean was 5.0, 3, 11.3 and 12.0% on average for peak oxygen consumption, peak heart rate (HR), anaerobic threshold and minute ventilation – carbonic dioxide production slope respectively. Cronbach’s alpha coefficient of peak oxygen consumption and anaerobic threshold were 0.992 and 0.919. In the stepper exercise testing of the hemiplegic participants, the ratio of peak HR to age-predicted maximal HR was 75% on average. Peak respiratory exchange ratio (mean ± standard deviation = 1.17 ± 0.08) was not different from that of healthy controls (1.21 ± 0.09). Notably, VO2 trajectory in relation to work rate is nonlinear and different in the rest-retest.This is the first research to study CPET variables in detail using stepper in patients with hemiplegia. CPET variables associated with peak are valid and reliable; nonetheless, those with sub-maximum are not. The study provides a method to do exercise testing for the patients with hemiplegia and its notice in application.

Vishram-Nielsen JKK; Deis T; Rossing K; Wolsk E; Alba AC; Gustafsson F;

Scandinavian cardiovascular journal : SCJ [Scand Cardiovasc J] 2020 Jul 15, pp. 1-8. Date of Electronic Publication: 2020 Jul 15.

Objective: To examine clinical characteristics and outcomes in women and men referred for advanced heart failure (HF) therapies such as left ventricular assist device (LVAD) or heart transplantation (HTx).
Design: A retrospective study of 429 (23% women) consecutive adult HF patients not on inotropic or mechanical circulatory support with left ventricular ejection fraction ≤45% referred for assessment of advanced HF therapies at a single tertiary institution between 2002 and 2016. Clinical characteristics and outcomes were compared in women and men, and all patients underwent right heart catheterization (RHC).
Results: At evaluation, women were younger than men (48 ± 13 vs. 51 ± 12 years, p  = .02), and less likely to have ischemic cardiomyopathy. There were no significant differences in NYHA class, contemporary HF therapy use, or physical examination findings, except for lower jugular vein distension and body surface area in women. On RHC, women had lower cardiac filling pressures, but similar pulmonary vascular resistance and cardiac index. Peak oxygen uptake from cardiopulmonary exercise testing was similar in both sexes. At total follow-up time, there were 164 deaths (21% vs. 44%, p  < .0001), 46 LVADs (3% vs. 13%, p  = .005), 110 HTxs (32% vs. 25%, p  = .15), and 82 HTxs without requiring LVAD (29% vs. 16%, p  = .03) in women and men. The time from RHC to HTx (±LVAD) was significantly shorter in women compared to men. Female sex was significantly associated with higher survival independent of time-trend, age, and comorbidities.
Conclusion: At evaluation, hemodynamics were less deranged in women. A higher proportion of women received HTx, their waitlist time was shorter, and survival greater.