Takken T; Sonbahar Ulu H; Hulzebos EH;

Expert review of respiratory medicine [Expert Rev Respir Med] 2020 Apr 07. Date of Electronic Publication: 2020 Apr 07.

Introduction : Cardiopulmonary exercise testing (CPET) quantitates and qualitates the integrated physiological response of a person to incremental exercise and provides additional information compared to static lung function tests alone.
Areas covered : This review covers rationale for the use of CPET parameters beyond the usual parameters like peak oxygen uptake and peak minute ventilation in children with respiratory disease.
Expert opinion : CPET provides a wealth of data from rest, submaximal and maximal exercise and data during recovery from exercise. In this review an interpretative approach is described for analyzing CPET data in children with respiratory disease.

Popovic D; Arena R; Jakovljevic D; Ristic A; Guazzi M;

Clinical cardiology [Clin Cardiol] 2020 Apr 09. Date of Electronic Publication: 2020 Apr 09.

Background: Continued high mortality in heart failure patients indicates the need for additional methods of risk stratification and phenotyping.
Hypothesis: We hypothesized that ventricular arrhythmias that do not meet test-termination criteria (non-terminating ventricular arrhythmias [NTVA]) during cardiopulmonary exercise testing (CPET) may help in phenotyping disease severity and prognosis in heart failure with reduced (HFrEF) and midrange (HFmrEF)/preserved (HFpEF) left ventricular ejection fraction (LVEF).
Methods: About 319 patients with heart failure (199 HFrEF; 80 HFmrEF; 41 HFpEF) underwent CPET. Tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) were measured by echocardiography. B-type natriuretic peptide (BNP) at rest and peak exercise was also determined. The patients were tracked for primary (cardiac death) and secondary composite outcomes (all-cause death, heart transplantation/left ventricular assist device implantation, hospitalization for cardiac reasons).
Results: Forty-seven (15%) of the patients demonstrated NTVA during CPET, regardless of coronary artery disease prevalence. Patients without arrhythmias had a significantly higher LVEF (P < .05), TAPSE/PASP ratio (P < .001), peak oxygen consumption (P < .01), lower resting and peak BNP (P < .001), and the minute ventilation/carbon dioxide production slope (P < .001) compared to those with NTVA. Seventy-one patients died during the tracking period, 54 for cardiac reasons. NTVA during CPET was a significant predictor of primary and secondary outcomes in the total heart failure cohort (HR: 5.3, 3.7; 95% CI: 3.1-9.1, 2.4-5.5; P < .001, respectively), as well as in subgroups categorized according to reduced and middle-range/preserved LVEF (P < .001).
Conclusion: Exercise-induced ventricular arrhythmias that do not reach test-termination criteria are nonetheless indicative of an advanced disease severity phenotype and worse prognosis.

Pymer, S.  Nichols, S. Prosser, J. Birkett, S. Carroll, S. Ingle, L.

Eur J Prev Cardiol. 2020;27(6):579-589.

BACKGROUND: In the United Kingdom (UK), exercise intensity is prescribed from a fixed percentage range (% heart rate reserve (%HRR)) in cardiac rehabilitation programmes. We aimed to determine the accuracy of this approach by comparing it with an objective, threshold-based approach incorporating the accurate determination of ventilatory anaerobic threshold (VAT). We also aimed to investigate the role of baseline cardiorespiratory fitness status and exercise testing mode dependency (cycle vs. treadmill ergometer) on these relationships.

DESIGN AND METHODS: A maximal cardiopulmonary exercise test was conducted on a cycle ergometer or a treadmill before and following usual-care circuit training from two separate cardiac rehabilitation programmes from a single region in the UK. The heart rate corresponding to VAT was compared with current heart rate-based exercise prescription guidelines.

RESULTS: We included 112 referred patients (61 years (59-63); body mass index 29 kg.m(-2) (29-30); 88% male). There was a significant but relatively weak correlation (r = 0.32; p = 0.001) between measured and predicted %HRR, and values were significantly different from each other (p = 0.005). Within this cohort, we found that 55% of patients had their VAT identified outside of the 40-70% predicted HRR exercise training zone. In the majority of participants (45%), the VAT occurred at an exercise intensity <40% HRR. Moreover, 57% of patients with low levels of cardiorespiratory fitness achieved VAT at <40% HRR, whereas 30% of patients with higher fitness achieved their VAT at >70% HRR. VAT was significantly higher on the treadmill than the cycle ergometer (p < 0.001).

CONCLUSION: In the UK, current guidelines for prescribing exercise intensity are based on a fixed percentage range. Our findings indicate that this approach may be inaccurate in a large proportion of patients undertaking cardiac rehabilitation.

Philip Maffetone , Paul B. Laursen

Front.Physiol. 02 April 2020         https://doi.org/10.3389/fphys.2020.00296

The earliest humans relied on large quantities of metabolic energy from the oxidation of fatty acids to develop larger brains and bodies, prevent and reduce disease risk, extend longevity, in addition to other benefits. This was enabled through the consumption of a high fat and low-carbohydrate diet (LCD). Increased fat oxidation also supported daily bouts of prolonged, low-intensity, aerobic-based physical activity. Over the past 40-plus years, a clinical program has been developed to help people manage their lifestyles to promote increased fat oxidation as a means to improve various aspects of health and fitness that include reducing excess body fat, preventing disease, and optimizing human performance. This program is referred to as maximum aerobic function, and includes the practical application of a personalized exercise heart rate (HR) formula of low-to-moderate intensity associated with maximal fat oxidation (MFO), and without the need for laboratory evaluations. The relationship between exercise training at this HR and associated laboratory measures of MFO, health outcomes and athletic performance must be verified scientifically.

Dawkins C; Hollingsworth AC; Milburn S; Cheesman M; Walker P; Mofidi R;

The Journal of cardiovascular surgery [J Cardiovasc Surg (Torino)] 2020 Apr 01. Date of Electronic Publication: 2020 Apr 01.

Background: Vascular Services Quality Improvement Program (VSQIP) was introduced to reduce mortality from elective repair of AAA in the United Kingdom. This study examines the differences in perioperative mortality and postoperative survival between men and women following elective repair of AAAs in the 10 years after implementation of the (VSQIP).
Methods: Consecutive patients who underwent elective repair of AAA between 1stJanuary 2008 and 31st March 2018 were included. All patients were assessed using the nationally agreed VSQIP pathway which involved cardiopulmonary exercise testing as well as contrast enhanced CT scan of aorta and multidisciplinary assessment to plan each treatment. CT scans were examined to assess the morphology of AAA. Patients were stratified by age, gender, AAA morphology and preoperative anaerobic threshold. Postoperative survival was assessed using Kaplan-Meier analysis. Cox regression analysis was used to determine predictors of postoperative mortality.
Results: A total of 702 patients underwent elective repair of AAA of whom 632 were men and 70 were women. The mean age of study cohort was 73.5 years (std. dev: 7.3) and mean AAA diameter was 62 mm (std. dev.: 9.9). Two hundred and forty four patients underwent open repair, 402 underwent standard infra renal Endovascular Aneurysm Repair (EVAR) and 56 underwent complex EVAR with perioperative and 30 day mortality of 1.13%. No significant difference was observed in perioperative/30 day mortality between men and women (χ2=0.06, P=0.81). Anaerobic threshold< 8 (HR: 95%CI: 0.68 (0.51-0.92)), complex aneurysm morphology (HR: 95%CI: 1.7 (1.39-2.19)) risk category (HR: 95%CI: 1.89 (1.48-2.42)) and patients age (HR: 95%CI: 1.41 (1.13-1.89)) were independent risk factor for mortality following repair of AAA, whilst female gender [(HR: 95%CI: 0.89 (0.54-1.48)] and AAA size [(HR: 95%CI: 1.01 (0.84-1.22)] were not. There was no difference in post- operative survival between men and women who underwent elective repair of AAA (Log rank: 1.82 P=0.61).
Conclusions: Following the implementation of VSQIP female gender is no longer a significant risk factor for perioperative mortality or reduced survival following elective repair of large asymptomatic AAA.

Straw S; Waduud MA; Drozd M; Warman P; Bailey MA; Hammond CJ; Abdel-Rahman S; Witte KK; Scott D;

Annals of the Royal College of Surgeons of England [Ann R Coll Surg Engl] 2020 Apr 01, pp. 1-8. Date of Electronic Publication: 2020 Apr 01.

Introduction: Cardiopulmonary exercise testing (CPET) and transthoracic echocardiography (TTE) are common preparative investigations prior to elective endovascular aneurysm repair (EVAR). Whether these investigations can predict survival following EVAR and contribute to shared decision making is unknown.
Methods: Patients who underwent EVAR at a tertiary centre between June 2007 and December 2014 were identified from the National Vascular Registry. Variables obtained from preoperative investigations were assessed for their association with survival at three years. Regression analysis was used to determine variables that independently predicted survival at three years.
Results: A total of 199 patients underwent EVAR during the study period. Of these, 120 had preoperative CPET and 123 had TTE. Lower forced expiratory ventilation (FEV ₁ ), ratio of FEV ₁ to forced vital capacity, work at peak oxygen consumption and higher ventilatory equivalent for carbon dioxide were associated with increased mortality. Variables obtained from TTE were not associated with survival at three years although there was a low incidence of left ventricular systolic dysfunction and significant valvular disease in this cohort.
Conclusions: CPET might be a useful adjunct to assist in shared decision making in patients undergoing elective EVAR and may influence anaesthetic technique. TTE does not appear to be able to discriminate between high and low risk individuals. However, a low rate of significant ventricular dysfunction and valvular disease in patients undergoing elective EVAR may account for these findings.

Eckerström F; Rex CE; Maagaard M; Heiberg J; Rubak S; Redington A; Hjortdal VE;

International journal of cardiology [Int J Cardiol] 2020 Feb 27. Date of Electronic Publication: 2020 Feb 27.

Background: There are increasing reports of cardiac and exercise dysfunction in adults with small, unrepaired ventricular septal defects (VSDs). The primary aim of this study was to evaluate pulmonary function in adults with unrepaired VSDs, and secondly to assess the effects of 900 μg salbutamol on lung function and exercise capacity.
Methods: Young adult patients with small, unrepaired VSDs and healthy age- and gender-matched controls were included in a double-blinded, randomised, cross-over study. Participants underwent static and dynamic spirometry, impulse oscillometry, multiple breath washout, diffusion capacity for carbon monoxide, and ergometer bicycle cardiopulmonary exercise test.
Results: We included 30 patients with VSD (age 27 ± 6 years) and 30 controls (age 27 ± 6 years). Patients tended to have lower FEV ₁ , 104 ± 11% of predicted, compared with healthy controls, 110 ± 14% (p = 0.069). Furthermore, the patient group had lower peak expiratory flow (PEF), 108 ± 20% predicted, compared with the control group, 118 ± 17% (p = 0.039), and showed tendencies towards lower forced vital capacity and increased airway resistance compared with controls. During exercise, the patients had lower oxygen uptake, 35 ± 8 ml/min/kg (vs 47 ± 7 ml/min/kg, p < 0.001), minute ventilation, 1.5 ± 0.5 l/min/kg (vs 2.1 ± 0.3 l/min/kg, p < 0.001) and breath rate, 48 ± 11 breaths/min (vs 55 ± 8 breaths/min, p = 0.008), than controls.
Conclusion: At rest, young adults with unrepaired VSDs are no different in pulmonary function from controls. However, when the cardiorespiratory system is stressed, VSD patients demonstrate significantly impaired minute ventilation and peak oxygen uptake, which may be early signs of parenchymal dysfunction and restrictive airway disease. These abnormalities were unaffected by the inhalation of salbutamol.

Chiu KL; Hsieh PC; Wu CW; Tzeng IS; Wu YK; Lan CC;

Heart & lung : the journal of critical care [Heart Lung] 2020 Mar 18. Date of Electronic Publication: 2020 Mar 18.

Background: How respiratory muscle strength influences the effectiveness of pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD) is unclear.
Objective: To investigate the benefits of PR in subjects with COPD according to respiratory muscle strength.
Methods: Ninety-seven subjects with COPD were evaluated using maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), pulmonary function tests, the cardiopulmonary exercise test (CPET), and the St. George’s Respiratory Questionnaire (SGRQ). Subjects were divided into four groups: 1 (normal MIP and MEP); 2 (low MIP); 3 (low MEP); and 4 (low MIP and MEP). Subjects underwent PR for 3 months; MIP, MEP, SGRQ, and CPET were evaluated post-PR.
Results: Subjects with both poor MIP and MEP had the highest dyspnea score, lowest exercise capacity, and poorest health-related quality of life (HRQoL). PR improved exercise capacity and HRQoL in all groups, with more improvement in MIP, MEP, tidal volume (on exercise), and dyspnea (at rest) in subjects with both low MIP and MEP.
Conclusions: Patients with respiratory muscle weakness had worse dyspnea, lower exercise capacity, and poorer HRQoL at baseline. Exercise training improved respiratory muscle strength with concurrent improvement of exercise capacity, HRQoL, and dyspnea score. Subjects with both poor baseline MIP and MEP showed greater benefits of PR.

Wagoner CW; Hanson ED; Ryan ED; Brooks R; Wood WA; Jensen BC; Lee JT;
Coffman EM; Battaglini CL.

Applied Physiology, Nutrition, & Metabolism = Physiologie Appliquee,
Nutrition et Metabolisme. 44(11):1159-1164, 2019 Nov.
VI 1

It is not uncommon for sedentary individuals to cite leg fatigue as the
primary factor for test termination during a cardiopulmonary exercise test
(CPET) on a cycle ergometer. The purpose of this study was to examine the
effect of 2 weeks of lower body resistance training (RT) on
cardiopulmonary capacity in sedentary middle-aged females. Additionally,
the impact of RT on muscle strength was evaluated.
Following familiarization, 28 women (18 exercise group, 10 control group) completed
a maximal CPET on a cycle ergometer to determine peak oxygen uptake and
leg extensor strength assessed using isokinetic dynamometry. Participants
in the exercise group performed 2 weeks (6 sessions) of lower body RT,
which comprised leg press, leg curl, and leg extension exercises.
A 2-way repeated-measures ANOVA was used to evaluate the difference in changes of
peak oxygen uptake and peak torque (PT). Peak oxygen uptake significantly
improved from 22.2 +/- 4.5 mL.kg-1.min-1 to 24.3 +/- 4.4 mL.kg-1.min-1
(10.8%, p < 0.05) as well as PT from 83.1 +/- 25.4 Nm to 89.0 +/- 29.7 Nm
(6.1%, p < 0.05) in the exercise group with no change in the control
group.
These findings provide initial evidence that 2 weeks of lower body
RT prior to a CPET may be a helpful preconditioning strategy to achieve a
more accurate peak oxygen uptake during testing, enhancing tolerability to
a CPET by improving lower body strength.

Takayanagi Y; Koike A; Kubota H; Wu L; Nishi I; Sato A; Aonuma K; Kawakami
Y; Ieda M.

Drug Discoveries & Therapeutics. 14(1):21-26, 2020 Mar 08.
VI 1

The pulse wave transit time (PWTT) is easily measured as the time from the
R wave of an electrocardiogram to the arrival of the pulse wave measured
by an oxygen saturation monitor at the earlobe. We investigated whether
the change of PWTT during exercise testing reflects cardiopulmonary
function. Eighty-nine cardiac patients who underwent cardiopulmonary
exercise testing (CPX) were enrolled. We analyzed the change of PWTT
during exercise and the relationship between the shortening of the PWTT
and CPX parameters. PWTT was significantly shortened from rest to peak
exercise (204.6 +/- 33.6 vs. 145.6 +/- 26.4 msec, p < 0.001) in all of the
subjects. The patients with heart failure had significantly higher PWTT at
peak exercise than the patients without heart failure (152.7 +/- 27.1 vs.
140.4 +/- 24.8 msec, p = 0.031). The shortening of PWTT from rest to peak
exercise showed significant positive correlations with the peak O2 uptake
(VO2) (r = 0.56, p < 0.001), anaerobic threshold (r = 0.40, p = 0.016),
and % increase of systolic blood pressure during exercise (r = 0.75, p <
0.001), and a negative correlation with the slope of the increase in
ventilation versus the increase in CO2 output (VE-VCO2 slope) (r = – 0.42,
p = 0.010) in the patients with heart failure. PWTT was shortened during
exercise as the exercise intensity increased. In the patients with heart
failure, the shortening of PWTT from rest to peak exercise was smaller in
those with lower exercise capacity and those with higher VE-VCO2 slope, an
established index known to reflect the severity of heart failure.