Denise L. Smith; Elliot L. Graham; Julie A. Douglas;  Kepra Jack; Michael J. Conner;
Ross Arena; Sundeep Chaudhry;

The American Journal of Medicine (2022) 000:1−9

BACKGROUND: Past studies have documented the ability of cardiopulmonary exercise testing to detect cardiac
dysfunction in symptomatic patients with coronary artery disease. Firefighters are at high risk for
work-related cardiac events. This observational study investigated the association of subclinical cardiac
dysfunction detected by cardiopulmonary exercise testing with modifiable cardiometabolic risk factors in
asymptomatic firefighters.
METHODS: As part of mandatory firefighter medical evaluations, study subjects were assessed at 2 occupational
health clinics serving 21 different fire departments. Mixed effects logistic regression analyses were
used to estimate odds ratios (ORs) and account for clustering by fire department.
RESULTS: Of the 967 male firefighters (ages 20-60 years; 84% non-Hispanic white; 14% on cardiovascular
medications), nearly two-thirds (63%) had cardiac dysfunction despite having normal predicted cardiorespiratory
fitness (median peak VO2 = 102%). In unadjusted analyses, cardiac dysfunction was significantly
associated with advanced age, obesity, diastolic hypertension, high triglycerides, low high-density lipoprotein
(HDL) cholesterol, and reduced cardiorespiratory fitness (all P values < .05). After adjusting for age
and ethnicity, the odds of having cardiac dysfunction were approximately one-third higher among firefighters
with obesity and diastolic hypertension (OR = 1.39, 95% confidence interval [CI] = 1.03-1.87 and
OR = 1.36, 95% CI = 1.03-1.80) and more than 5 times higher among firefighters with reduced cardiorespiratory
fitness (OR = 5.41, 95% CI = 3.29-8.90).
CONCLUSION: Subclinical cardiac dysfunction detected by cardiopulmonary exercise testing is a common
finding in career firefighters and is associated with substantially reduced cardiorespiratory fitness and cardiometabolic risk factors. These individuals should be targeted for aggressive risk factor modification to
increase cardiorespiratory fitness as part of an outpatient prevention strategy to improve health and safety.

Ohara K; Imamura T; Ihori H; Chatani K; Nonomura M; Kameyama T; Inoue H;

Journal of clinical medicine [J Clin Med] 2022 Feb 18; Vol. 11 (4).
Date of Electronic Publication: 2022 Feb 18.

Background: The association between right ventricular function and exercise capacity in patients with chronic heart failure remains uncertain. Several studies very recently mentioned the association between right ventricular reserve and exercise capacity, whereas the implication of tricuspid annular plane systolic excursion (TAPSE) remains uninvestigated. We aimed to assess the impact of TAPSE on exercise capacity in cardiac rehabilitation candidates.
Methods: Data from patients with chronic heart failure who received cardiopulmonary exercise tests and transthoracic echocardiography prior to cardiac rehabilitation were retrospectively collected, and their association was investigated.
Results: A total of 169 patients with chronic heart failure (70.3 ± 11.7 years old, 74.6% men) were included. Tertiled tricuspid annular plane systolic excursion significantly stratified anaerobic threshold (10.2 ± 2.2, 11.4 ± 2.2, and 12.2 ± 2.8 mm; p < 0.01) and peak oxygen consumption (15.9 ± 4.5, 18.3 ± 5.3, and 19.8 ± 5.6 mm; p < 0.01). In the multivariate logistic regression analyses, TAPSE was an independent factor associated with anaerobic threshold and peak oxygen consumption ( p < 0.05 for both).
Conclusions: Right ventricular impairment was associated with reduced exercise capacity in patients with chronic heart failure. Such knowledge would be useful to estimate patients’ exercise capacity and prescribe cardiac rehabilitation. Its longitudinal association and clinical implication need further studies.

Evers G; Schulze AB; Osiaevi I; Harmening K; Vollenberg R; Wiewrodt R; Pistulli R; Boentert M; Tepasse PR; Sindermann JR; Yilmaz A; Mohr M;

Canadian respiratory journal [Can Respir J] 2022 Mar 01; Vol. 2022, pp. 2466789.
Date of Electronic Publication: 2022 Mar 01 (Print Publication: 2022).

Background: Following COVID-19, patients often present with ongoing symptoms comparable to chronic fatigue and subjective deterioration of exercise capacity (EC), which has been recently described as postacute COVID-19 syndrome.
Objective: To objectify the reduced EC after COVID-19 and to evaluate for pathologic limitations.
Methods: Thirty patients with subjective limitation of EC performed cardiopulmonary exercise testing (CPET). If objectively limited in EC or deteriorated in oxygen pulse, we offered cardiac stress magnetic resonance imaging (MRI) and a follow-up CPET.
Results: Eighteen male and 12 female patients were included. Limited relative EC was detected in 11/30 (36.7%) patients. Limitation correlated with reduced body weight-indexed peak oxygen (O ₂ ) uptake (peakV̇O ₂ /kg) (mean 74.7 (±7.1) % vs. 103.6 (±14.9) %, p < 0.001). Reduced peakV̇O ₂ /kg was found in 18/30 (60.0%) patients with limited EC. Patients with reduced EC widely presented an impaired maximum O ₂ pulse (75.7% (±5.6) vs. 106.8% (±13.9), p < 0.001). Abnormal gas exchange was absent in all limited EC patients. Moreover, no patient showed signs of reduced pulmonary perfusion. Using cardiac MRI, diminished biventricular ejection fraction was ruled out in 16 patients as a possible cause for reduced O ₂ pulse. Despite noncontrolled training exercises, follow-up CPET did not reveal any exercise improvements.
Conclusions: Deterioration of EC was not associated with ventilatory or pulmonary vascular limitation. Exercise limitation was related to both reduced O ₂ pulse and peakV̇O ₂ /kg, which, however, did not correlate with the initial severity of COVID-19. We hypothesize that impaired microcirculation or limited peripheral O ₂ utilization might be causative for prolonged deterioration of EC following acute COVID-19 infection.

Lewis GD; Docherty KF; Voors AA; Cohen-Solal A; Metra M; Whellan DJ; .Ezekowitz JA; Ponikowski P; Böhm M; Teerlink JR; Heitner SB; Kupfer S; Malik FI; Meng L; Felker GM;

Circulation. Heart failure [Circ Heart Fail] 2022 Mar 03, pp. CIRCHEARTFAILURE121008970.
Date of Electronic Publication: 2022 Mar 03.

Heart failure with reduced ejection fraction (HFrEF) is a highly morbid condition for which exercise intolerance is a major manifestation. However, methods to assess exercise capacity in HFrEF vary widely in clinical practice and in trials. We describe advances in exercise capacity assessment in HFrEF and a comparative analysis of how various therapies available for HFrEF impact exercise capacity. Current guideline-directed medical therapy has indirect effects on cardiac performance with minimal impact on measured functional capacity. Omecamtiv mecarbil is a novel selective cardiac myosin activator that directly increases cardiac contractility and in a phase 3 cardiovascular outcomes study significantly reduced the primary composite end point of time to first heart failure event or cardiovascular death in patients with HFrEF. The objective of the METEORIC-HF trial (Multicenter Exercise Tolerance Evaluation of Omecamtiv Mecarbil Related to Increased Contractility in Heart Failure) is to assess the effect of omecamtiv mecarbil versus placebo on multiple components of functional capacity in HFrEF. The primary end point is to test the effect of omecamtiv mecarbil compared with placebo on peak oxygen uptake as measured by cardiopulmonary exercise testing after 20 weeks of treatment. METEORIC-HF will provide state-of-the-art assessment of functional capacity by measuring ventilatory efficiency, circulatory power, ventilatory anaerobic threshold, oxygen uptake recovery kinetics, daily activity, and quality-of-life assessment. Thus, the METEORIC-HF trial will evaluate the potential impact of increased myocardial contractility with omecamtiv mecarbil on multiple important measures of functional capacity in ambulatory patients with symptomatic HFrEF.

Triantafyllidi H; Birmpa D; Benas D; Trivilou P; Fambri A; Iliodromitis EK

Cardiology. 147(1):62-71, 2022.

BACKGROUND: Cardiopulmonary exercise testing (CPET) is the most
comprehensive technique which allows a holistic approach to
cardiopulmonary diseases.

SUMMARY: This article provides basic information addressed to the
Clinical Cardiologist regarding the utility and the indications of the
CPET technique in the everyday clinical practice. Clinical application of
CPET continues to evolve and protocols should be adapted to each specific
patient to obtain the most reliable and useful information. Key Messages:
Clinical Cardiologists with an interest over CPET may become familiar with
this exercise method and its main measured variables, refresh their
knowledge regarding the underlying pathophysiological mechanisms of oxygen
transport chain, learn how to interpret the CPET results and promote
appropriate patient referrals to experts.

Wiecha S; Price S; Cieslinski I; Kasiak PS; Tota L; Ambrozy T; Sliz D

International Journal of Environmental Research & Public Health
[Electronic Resource]. 19(3), 2022 02 06.

Cardiopulmonary exercise testing (CPET) on a treadmill (TE) or cycle
ergometry (CE) is a common method in sports diagnostics to assess
athletes’ aerobic fitness and prescribe training. In a triathlon, the gold
standard is performing both CE and TE CPET. The purpose of this research
was to create models using CPET results from one modality to predict
results for the other modality. A total of 152 male triathletes (age =
38.20 +/- 9.53 year; BMI = 23.97 +/- 2.10 kg.m-2) underwent CPET on TE and
CE, preceded by body composition (BC) analysis. Speed, power, heart rate
(HR), oxygen uptake (VO2), respiratory exchange ratio (RER), ventilation
(VE), respiratory frequency (fR), blood lactate concentration (LA) (at the
anaerobic threshold (AT)), respiratory compensation point (RCP), and
maximum exertion were measured. Random forests (RF) were used to find the
variables with the highest importance, which were selected for multiple
linear regression (MLR) models. Based on R2 and RF variable selection, MLR
equations in full, simplified, and the most simplified forms were created
for VO2AT, HRAT, VO2RCP, HRRCP, VO2max, and HRmax for CE (R2 = 0.46-0.78)
and TE (R2 = 0.59-0.80). By inputting only HR and power/speed into the RF,
MLR models for practical HR calculation on TE and CE (both R2 = 0.41-0.75)
were created. BC had a significant impact on the majority of CPET
parameters. CPET parameters can be accurately predicted between CE and TE
testing. Maximal parameters are more predictable than submaximal. Only HR
and speed/power from one testing modality could be used to predict HR for
another. Created equations, combined with BC analysis, could be used as a
method of choice in comprehensive sports diagnostics.

Winkert K; Kirsten J; Kamnig R; Steinacker JM; Treff G

International journal of sports physiology & performance.
16(9):1335-1340, 2021 Mar 26.

PURPOSE: Automated metabolic analyzers are frequently utilized to measure
maximal oxygen consumption (VO2max). However, in portable devices, the
results may be influenced by the analyzer’s technological approach, being
either breath-by-breath (BBB) or dynamic micro mixing chamber mode (DMC).
The portable metabolic analyzer K5 (COSMED, Rome, Italy) provides both
technologies within one device, and the authors aimed to evaluate
differences in VO2max between modes in endurance athletes.

METHODS: Sixteen trained male participants performed an incremental test
to voluntary exhaustion on a cycle ergometer, while ventilation and gas
exchange were measured by 2 structurally identical COSMED K5 metabolic
analyzers synchronously, one operating in BBB and the other in DMC mode.
Except for the flow signal, which was measured by 1 sensor and transmitted
to both devices, the devices operated independently. VO2max was defined as
the highest 30-second average.

RESULTS: VO2max and VCO2@VO2max were significantly lower in BBB compared
with DMC mode (-4.44% and -2.71%), with effect sizes being large to
moderate (ES, Cohen d = 0.82 and 1.87). Small differences were obtained
for respiratory frequency (0.94%, ES = 0.36), minute ventilation (0.29%,
ES = 0.20), and respiratory exchange ratio (1.74%, ES = 0.57).

CONCLUSION: VO2max was substantially lower in BBB than in DMC mode.
Considering previous studies that also indicated lower VO2 values in BBB
at high intensities and a superior validity of the K5 in DMC mode, the
authors conclude that the DMC mode should be selected to measure VO2max in
athletes.

Oleksak F; Spakova B; Durdikova A; Durdik P; Kralova T; Igaz M; Molnar M;
Gura M; Murgas D

Respiratory Physiology & Neurobiology. 296:103790, 2022 02.

OBJECTIVE: The objective was to use CPET to estimate the usability of
anthropometric index (AI) in patients with pectus excavatum (PE) as a
marker of functional impairment caused by chest deformity.

METHODS: The study included 32 paediatric patients (28 males) with PE.
Patients underwent CPET using a breath-by-breath exhaled gas analysis
method and continuous monitoring of cardiac parameters.

RESULTS: In both groups, two (overall four) patients met criteria for
cardiogenic limitation (low VO2 and low O2Pulse). Mean VO2/WR was below
two standard deviations (2SD) in patients with less severe PE; other
observed parameters were within normal limits (Z-score +/- 2 SD). The AI
had no observed correlation with peak ventilation, VO2peak and peak
workload.

CONCLUSION: The obtained CPET data do not correlate well with the
severity of chest deformity expressed with AI. There were similar physical
activity limitations in both examined groups of patients and they did not
depend on the severity of the deformity.

von Gruenewaldt, Anna; Nylander, Eva; Hedman, Kristofer.

Physiological Reports. 10(4):e15197, 2022 02.

Reduced exercise capacity and several limiting symptoms during exercise
have been reported following severe acute respiratory syndrome
coronavirus-2 (SARS-CoV-2) infection. From clinical observations, we
hypothesized that an abnormal breathing pattern (BrP) during exercise may
be common in these patients and related to reduced exercise capacity. We
aimed to (a) evaluate a method to classify the BrP as normal/abnormal or
borderline in terms of inter-rater agreement; (b) determine the occurrence
of an abnormal BrP in patients with post-COVID; and (c) compare
characteristics of post-COVID patients with normal and abnormal BrP. In a
retrospective, cross-sectional study of patients referred for CPET due to
post-COVID April 2020-April 2021, we selected subjects without a history
of intensive care and with available medical records. Three raters
independently categorized patients’ BrP as normal, abnormal, or
borderline, using four traditional CPET plots (respiratory exchange ratio,
tidal volume over ventilation, ventilatory equivalent for oxygen, and
ventilation over time). Out of 20 patients (11 male), 10 were categorized
as having a normal, 7 an abnormal, and three a borderline BrP. Inter-rater
agreement was good (Fleiss’ kappa: 0.66 [0.66-0.67]). Subjects with an
abnormal BrP had lower peak ventilation, lower exercise capacity, similar
ventilatory efficiency and a similar level of dyspnea at peak exercise, as
did subjects with a normal BrP. Patients’ BrP was possible to classify
with good agreement between observers. A third of patients had an abnormal
BrP, associated with lower exercise capacity, which could possibly explain
exercise related symptoms in some patients with post-COVID syndrome.

Peterman JE; Arena R; Myers J; Marzolini S; Ades PA; Savage PD; Lavie CJ;
Kaminsky LA

Journal of the American Heart Association. 10(22):e022336, 2021 11 16.
VI 1

Background The importance of cardiorespiratory fitness for stratifying
risk and guiding clinical decisions in patients with cardiovascular
disease is well-established. To optimize the clinical value of
cardiorespiratory fitness, normative reference standards are essential.
The purpose of this report is to extend previous cardiorespiratory fitness
normative standards by providing updated cardiorespiratory fitness
reference standards according to cardiovascular disease category and
testing modality. Methods and Results The analysis included 15 045 tests
(8079 treadmill, 6966 cycle) from FRIEND (Fitness Registry and the
Importance of Exercise National Database). Using data from tests conducted
January 1, 1974, through March 1, 2021, percentiles of directly measured
peak oxygen consumption (VO2peak) were determined for each decade from 30
through 89 years of age for men and women with a diagnosis of coronary
artery bypass surgery, myocardial infarction, percutaneous coronary
intervention, or heart failure. There were significant differences between
sex and age groups for VO2peak (P<0.001). The mean VO2peak was 23% higher
for men compared with women and VO2peak decreased by a mean of 7% per
decade for both sexes. Among each decade, the mean VO2peak from treadmill
tests was 21% higher than the VO2peak from cycle tests. Differences in
VO2peak were observed among the age groups in both sexes according to
cardiovascular disease category. Conclusions This report provides
normative reference standards by cardiovascular disease category for both
men and women performing cardiopulmonary exercise testing on a treadmill
or cycle ergometer. These updated and enhanced reference standards can
assist with patient risk stratification and guide clinical care.