Martin-Rincon M; Calbet JAL;

Frontiers in physiology [Front Physiol] 2020 Sep 03; Vol. 11, pp. 1070. Date of Electronic Publication: 2020 Sep 03 (Print Publication: 2020).

The maximal oxygen uptake ( V.O_2max ) is the primary determinant of endurance performance in heterogeneous populations and has predictive value for clinical outcomes and all-cause mortality. Accurate and precise measurement of V.O_2max requires the adherence to quality control procedures, including combustion testing and the use of standardized incremental exercise protocols with a verification phase preceded by an adequate familiarization. The data averaging strategy employed to calculate the V.O_2max from the breath-by-breath data can change the V.O_2max value by 4-10%. The lower the number of breaths or smaller the number of seconds included in the averaging block, the higher the calculated V.O_2max value with this effect being more prominent in untrained subjects. Smaller averaging strategies in number of breaths or seconds (less than 30 breaths or seconds) facilitate the identification of the plateau phenomenon without reducing the reliability of the measurements. When employing metabolic carts, averaging intervals including 15-20 breaths or seconds are preferable as a compromise between capturing the true V.O_2max and identifying the plateau. In training studies, clinical interventions and meta-analysis, reporting of V.O_2max in absolute values and inclusion of protocols and the averaging strategies arise as imperative to permit adequate comparisons. Newly developed correction equations can be used to normalize V.O_2max to similar averaging strategies. A lack of improvement of V.O_2max with training does not mean that the training program has elicited no adaptations, since peak cardiac output and mitochondrial oxidative capacity may be increased without changes in V.O_2max .

Fleenor BS; Carlini NA; Kaminsky LA; Whaley MH; Peterman JE; Harber MP

Journal of cardiopulmonary rehabilitation and prevention [J Cardiopulm Rehabil Prev] 2020 Oct 05. Date of Electronic Publication: 2020 Oct 05.

Background: Healthy vascular aging (HVA) and cardiorespiratory fitness (CRF) are each independently associated with lower cardiovascular disease-related mortality. It is unknown, however, whether the CRF-related reductions in cardiovascular disease risk are related to HVA. We hypothesized that HVA would be associated with higher CRF in men and women from the Ball State Adult Fitness Longitudinal Lifestyle STudy (BALL ST).
Methods: Apparently healthy men and women ≥50 yr of age from the BALL ST cohort (n = 101) who underwent a maximal cardiopulmonary exercise test to assess CRF (VO2peak) were included in the study. Participants were divided into either HVA, defined as brachial systolic blood pressure <140/90 mm Hg without taking medications and carotid-femoral pulse wave velocity <7.6 m/sec, or no HVA for subjects with SBP >140/90 mm Hg and/or PWV >7.6 m/sec.
Results: Participants with HVA had a higher age- and sex-adjusted CRF percentile (62 ± 5 vs 47 ± 3, P < .05), with women having a greater prevalence of HVA than men (36% vs 15%, P < .05). Both carotid-femoral pulse wave velocity (r =-0.27, P < .05) and brachial systolic blood pressure (r =-0.23, P < .05) were independently and inversely associated with CRF for the entire cohort. Men and women with HVA were younger having a lower body fat percentage and higher low-density lipoprotein cholesterol (P < .05, all).
Conclusions: These data demonstrate that HVA is associated with higher CRF, which may partially explain the preventative cardioprotective effects of CRF.

Pugliese NR; De Biase N; Conte L; Gargani L; Mazzola M; Fabiani I; Natali A; Dini FL; Frumento P; Rosada J;
Taddei S; Borlaug BA; Masi S;

Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography [J Am Soc Echocardiogr] 2020 Oct 06. Date of Electronic Publication: 2020 Oct 06.

Background: Cardiopulmonary exercise testing (CPET) represents the gold standard to estimate peak oxygen consumption (VO ₂ ) noninvasively. To improve the analysis of the mechanisms behind effort intolerance, we examined whether exercise stress echocardiography measurements relate to directly measured peak VO ₂ during exercise in a large cohort of patients within the heart failure (HF) spectrum.
Methods: We performed a symptom-limited graded ramp bicycle CPET exercise stress echocardiography in 30 healthy controls and 357 patients: 113 at risk of developing HF (American College of Cardiology/American Heart Association stage A-B) and 244 in HF stage C with preserved (HFpEF, n = 101) or reduced ejection fraction (HFrEF, n = 143).
Results: Peak VO ₂ significantly decreased from controls (23, 21.7-29.7 mL/kg/minute; median, interquartile range) to stage A-B (18, 15.4-20.7 mL/kg/minute) and stage C (HFpEF: 13.6, 11.8-16.8 mL/kg/minute; HFrEF: 14.2, 10.7-17.5 mL/kg/minute). A regression model to predict peak VO ₂ revealed that peak left ventricular (LV) systolic annulus tissue velocity (S’), peak tricuspid annular plane systolic excursion/systolic pulmonary artery pressure (right ventricle-pulmonary artery coupling), and low-load left atrial (LA) reservoir strain/E/e’ (LA compliance) were independent predictors, in addition to peak heart rate, stroke volume, and workload (adjusted R ²  = 0.76, P < .0001). The model was successfully tested in subjects with atrial fibrillation (n = 49) and with (n = 224) and without (n = 163) beta-blockers (all P < .01). Peak S’ showed the highest accuracy in predicting peak VO ₂  < 10 mL/kg/minute (cut point ≤ 7.5 cm/sec, area under the curve = 0.92, P < .0001) and peak VO ₂  > 20 mL/kg/minute (cut point > 12.5 cm/sec, area under the curve = 0.84, P < .0001) in comparison with the other cardiac variables of the model (P < .05).
Conclusions: Peak VO ₂ is directly related to measures of LV systolic function, LA compliance, and right ventricle-pulmonary artery coupling, in addition to heart rate and stroke volume and independently of workload, age, and sex. The evaluation of cardiac mechanics may provide more insights into the causes of effort intolerance in subjects from HF stages A-C.

Schindel CS; Schiwe D; Heinzmann-Filho JP;Gheller MF; Campos NE; Pitrez PM; Donadio MVF;

The Journal of asthma : official journal of the Association for the Care of Asthma [J Asthma] 2020 Oct 07, pp. 1-13. Date of Electronic Publication: 2020 Oct 07.

Objective: To evaluate the exercise capacity of children and adolescents with severe therapy resistant asthma (STRA) aiming to identify its main determinants.
Methods: Cross-sectional study including individuals aged 6 to 18 years with a diagnosis of STRA. Clinical (age and gender), anthropometric (weight, height and body mass index) and disease control data were collected. Lung function (spirometry), cardiopulmonary exercise testing (CPET) and exercise-induced bronchoconstriction (EIB) test were performed.
Results: Twenty-four patients aged 11.5 ± 2.6 years were included. The mean forced expiratory volume in one second (FEV ₁ ) was 91.3 ± 9.2%. EIB occurred in 54.2% of patients. In CPET, the peak oxygen uptake (VO ₂ peak) was 34.1 ± 7.8 mL.kg ^-1 .min ^-1 . A significant correlation between ventilatory reserve and FEV ₁ (r = 0.57; p  = 0.003) was found. Similarly, there was a significant correlation between CPET and percent of FEV ₁ fall in the EIB test for both V _E /VO ₂ (r = 0.47; p  = 0.02) and V _E /VCO ₂ (r = 0.46; p  = 0.02). Patients with FEV ₁ <80% had lower ventilatory reserve ( p  = 0.009). In addition, resting heart rate correlated with VO ₂ peak (r=-0.40; p  = 0.04), V _E /VO ₂ (r = 0.46; p  = 0.02) and V _E /VCO ₂ (r = 0.48; p  = 0.01).
Conclusions: Exercise capacity is impaired in approximately 30% of children and adolescents with STRA. The results indicate that different aspects of aerobic fitness are influenced by distinct determinants, including lung function and EIB.

Jen R; Orr JE; Gilbertson D; Fine J; Li Y; Wong D; Hopkins SR; Raisingani A; Malhotra A;

Respiratory physiology & neurobiology [Respir Physiol Neurobiol] 2020 Oct 01, pp. 103557. Date of Electronic Publication: 2020 Oct 01.

Rationale: OSA has been associated with reduced exercise capacity. Endothelial dysfunction and exercise-induced pulmonary hypertension (ePH) may be mediators of this impairment. We hypothesized that OSA severity would be associated with impaired exercise performance, endothelial dysfunction, and ePH.
Methods: Subjects with untreated OSA were recruited. Subjects underwent endothelial function, and cardiopulmonary exercise testing with an echocardiogram immediately before and following exercise.
Results: 22 subjects were recruited with mean age 56 ± 8 years, 74 % male, BMI 29 ± 3 kg/m ² , and AHI 22 ± 12 events/hr. Peak V˙O ₂ did not differ from normal (99.7 ± 17.3 % predicted; p = 0.93). There was no significant association between OSA severity (as AHI, ODI) and exercise capacity, endothelial function, or pulmonary artery pressure. However, ODI, marker of RV diastolic dysfunction, and BMI together explained 59.3 % of the variability of exercise performance (p < 0.001) via our exploratory analyses.
Conclusions: Exercise capacity was not impaired in this OSA cohort. Further work is needed to elucidate mechanisms linking sleep apnea, obesity, endothelial dysfunction and exercise impairment.

Soumagne T; Guillien A; Roche N; Dalphin JC; Degano B;

Journal of applied physiology (Bethesda, Md. : 1985) [J Appl Physiol (1985)] 2020 Oct 01. Date of Electronic Publication: 2020 Oct 01.

Background: COPD in never-smokers exposed to organic dusts is still poorly characterized. Therapeutic strategies in COPD are only evaluated in smoking-related COPD. To understand how never-smokers with COPD behave during exercise is an important prerequisite for optimal management.
Objectives: To compare physiological parameters measured at exercise between never-smokers exposed to organic dusts with COPD and patients with smoking-related COPD matched for age, sex and severity of airway obstruction. Healthy controls were also studied.
Methods: Dyspnea (Borg scale), exercise tolerance and ventilatory constraints were assessed during incremental cycle cardiopulmonary exercise testing in COPD patients at mild-to-moderate stages (22 exposed to organic dusts, postbronchodilator FEV ₁ /FVC z-score: -2.44±0.72 and FEV ₁ z-score: -1.45±0.78; 22 with smoking-related COPD, FEV ₁ /FVC z-score: -2.45±0.61; FEV ₁ z-score: -1.43±0.69) and 44 healthy controls (including 22 never-smokers).
Results: Despite the occurrence of similar significant dynamic hyperinflation, never-smokers COPD patients exposed to organic dusts had lower dyspnea ratings than those with smoking-related COPD. They also had higher peak oxygen consumption, peak power output and better ventilatory efficiency than smoking-related COPD, all these parameters being similar controls. Differences in exercise capacity between the two groups of COPD were mainly driven by better ventilatory efficiency stemming from preserved diffusing capacity.
Conclusion Never-smokers exposed to organic dusts with mild-to-moderate COPD have better exercise capacities, better ventilatory efficiency and better diffusion capacity than matched patients with smoking-related COPD.

Nicol M; Deney A; Lairez O; Vergaro G; Emdin M;Inamo J; Montfort A; Neviere R; Damy T; Harel S;Royer B; Baudet M; Cohen-Solal A; Arnulf B;Logeart D;

European journal of heart failure [Eur J Heart Fail] 2020 Oct 02. Date of Electronic Publication: 2020 Oct 02.

Background: In amyloid patients, cardiac involvement dramatically worsens functional capacity and prognosis.
Purpose: We sought to study how the cardio-pulmonary exercise test (CPET) could help in functional assessment and risk stratification of patients with cardiac amyloidosis (CA).
Methods: We carried out a multicenter study including patients with light chain (AL) or transthyretin (TTR) CA. All patients underwent exhaustive examination including CPET and follow-up. The primary prognostic endpoint was the occurrence of death or heart failure (HF) hospitalization.
Results: We included 150 patients: 91 AL and 59 TTR CA. Median age, systolic blood pressure, NT-proBNP and cardiac troponin T were 70 [64-78] years old, 121 [IQR 109-139] mmHg, 2809 [IQR 1218-4638] ng/L and 64 [IQR 33-120] ng/L respectively. NYHA classes were I- II in 64%. Median peak VO ₂ and circulatory power were low at 13.0 mL/kg/min [10.0-16.9] and 1729 mmHg.mL ^-1 min ^_1 [1318-2614] respectively. The VE/VCO ₂ slope was increased to 37 [IQR 33-45]. Seventy-seven patients (51%) had chronotropic insufficiency. After a median follow-up of 20 months, there were 37 deaths and 44 HF hospitalizations. Multivariate Cox analysis shows that peak VO ₂  ≤ 13 mL/kg/min (HR 2.7; CI95% 1.6-4.8), circulatory power ≤ 1800 mmHg.mL.min ^-1 (HR 2.4; CI95% 1.2-4.6) and NT-proBNP ≥1800 ng/L (HR 2.2; CI95% 1.1-4.3) were associated with the primary outcome. There was no event in patients with both peak VO2 > 13 mL/kg/min and NTproBNP <1800 ng/L, while the association of VO2 ≤ 13 mL/kg/min and NTproBNP ≥1800 ng/L identified a very high-risk subgroup.
Conclusion: In CA, CPET helps to assess functional capacity, circulatory and chronotropic responses and helps to assess the prognosis of patients along with cardiac biomarkers.

Venturelli M; Cè E; Paneroni M; Guazzi M; Lippi G; Paoli A; Baldari C; Schena F; Esposito F;

Sport sciences for health [Sport Sci Health] 2020 Sep 11, pp. 1-7. Date of Electronic Publication: 2020 Sep 11.

Recent data on coronavirus disease 2019 (COVID-19) pandemic showed that the virus is mostly conveyed by respiratory droplets that are produced at high intensity especially when an infected subject coughs or sneezes. Therefore, elevated volume ventilations, usually reached during physical efforts and exercise, are a potential source of contamination. On the other hand, the lockdown period which has lasted for nearly 2 months and is actually involving several countries worldwide, obliged a large part of human population to sedentary behaviors, drastically reducing their physical activity level, and reducing their cardiopulmonary fitness. Therefore, cardiopulmonary exercise testing could be beneficial, so that a safe and well-weighted return to pre-lockdown active lifestyle can be efficiently planned. However, specific guidelines on exercise testing safety procedures in the era of COVID-19 are unavailable so far. This article is aimed to provide an overview of safety procedures for exercise testing during and after COVID-19 worldwide pandemic.

Abe T; Yokota T; Fukushima A; Kakutani N; Katayama T; Shirakawa R; Maekawa S; Nambu H; Obata Y; Yamanashi K; Nakano I; Takada S; Yokota I; Okita K; Kinugawa S; Anzai T;

Cardiovascular diabetology [Cardiovasc Diabetol] 2020 Sep 19; Vol. 19 (1), pp. 142. Date of Electronic Publication: 2020 Sep 19.

Background: Although type 2 diabetes mellitus (T2DM) is one of the most frequent comorbidities in patients with chronic heart failure (CHF), the effects of T2DM on the exercise capacity of CHF patients are fully unknown. Here, we tested the hypothesis that the coexistence of T2DM lowers CHF patients’ peak aerobic capacity.
Methods: We retrospectively analyzed the cases of 275 Japanese CHF patients with non-reduced ejection fraction (left ventricular ejection fraction [LVEF] ≥ 40%) or reduced EF (LVEF < 40%) who underwent cardiopulmonary exercise testing. We divided them into diabetic and nondiabetic groups in each CHF cohort.
Results: The mean peak oxygen uptake (VO ₂ ) value was 16.87 mL/kg/min in the non-reduced LVEF cohort and 15.52 mL/kg/min in the reduced LVEF cohort. The peak VO ₂ was lower in the diabetics versus the nondiabetics in the non-reduced LVEF cohort with the mean difference (95% confidence interval [95% CI]) of - 0.93 (- 1.82 to - 0.04) mL/kg/min and in the reduced LVEF cohort with the mean difference of - 1.05 (- 1.96 to - 0.15) mL/kg/min, after adjustment for age-squared, gender, anemia, renal function, LVEF, and log B-type natriuretic peptide (BNP). The adjusted VO ₂ at anaerobic threshold (AT), a submaximal aerobic capacity, was also decreased in the diabetic patients with both non-reduced and reduced LVEFs. Intriguingly, the diabetic patients had a lower adjusted peak O ₂ pulse than the nondiabetic patients in the reduced LVEF cohort, but not in the non-reduced LVEF cohort. A multivariate analysis showed that the presence of T2DM was an independent predictor of lowered peak VO ₂ in CHF patients with non-reduced LVEF and those with reduced LVEF.
Conclusions: T2DM was associated with lowered peak VO ₂ in CHF patients with non-reduced or reduced LVEF. The presence of T2DM has a negative impact on CHF patients’ exercise capacity, and the degree of impact is partly dependent on their LV systolic function.

Letnes JM; Dalen H; Aspenes ST; Salvesen Ø; Wisløff U; Nes BM;

Progress in cardiovascular diseases [Prog Cardiovasc Dis] 2020 Sep 21. Date of Electronic Publication: 2020 Sep 21.

Background: Large longitudinal studies on change in directly measured peak oxygen uptake (VO _2peak ) is lacking, and its significance for change of cardiovascular risk factors is uncertain. We aimed to assess ten-year change in VO _2peak and the influence of leisure-time physical activity (LTPA), and the association between change in VO _2peak and change in cardiovascular risk factors.
Methods and Results: A healthy general population sample had their VO _2peak directly measured in two (n = 1471) surveys of the Nord-Trøndelag Health Study (HUNT3; 2006-2008 and HUNT4; 2017-19). Average ten-year decline in VO _2peak was non-linear and progressed from 3% in the third to about 20% in the eight decade in life and was more pronounced in men. The fit linear mixed models including an additional 2933 observations from subjects participating only in HUNT3 showed similar age-related decline. Self-reported adherence to LTPA recommendations was associated with better maintenance of VO _2peak , with intensity seemingly more important than minutes of LTPA with higher age. Adjusted linear regression analyses showed that one mL/kg/min better maintenance of VO _2peak was associated with favorable changes of individual cardiovascular risk factors (all p ≤ 0.002). Using logistic regression one mL/kg/min better maintenance of VO _2peak was associated with lower adjusted odds ratio of hypertension (0.95 95% CI 0.92 to 0.98), dyslipidemia (0.92 95% CI 0.89 to 0.94), and metabolic syndrome (0.86 95% CI 0.83 to 0.90) at follow-up.
Conclusions: Although VO _2peak declines progressively with age, performing LTPA and especially high-intensity LTPA is associated with less decline. Maintaining VO _2peak is associated with an improved cardiovascular risk profile.