Author Archives: Paul Older

Pulmonary rehabilitation for COPD improves exercise time rather than exercise tolerance: effects and mechanisms.

Miki K, Maekura R, Kitada S, Miki M, Yoshimura K, Yamamoto H,
Kawabe T, Kagawa H, Oshitani Y, Satomi A, Nishida K, Sawa N,
Inoue K

Int J Chron Obstruct Pulmon Dis. 2017 Apr 3;12:1061-1070

BACKGROUND: COPD patients undergoing pulmonary rehabilitation (PR) show various
responses. The purpose of this study was to investigate the possible mechanisms
and predictors of the response to PR in COPD patients.
METHODS: Thirty-six stable COPD patients underwent PR including a 4-week
high-intensity exercise training program, and they were evaluated by
cardiopulmonary exercise testing. All patients (mean age 69 years, severe and
very severe COPD 94%) were classified into four groups by whether the exercise
time (Tex) or the peak oxygen uptake [Formula: see text] increased after PR: two
factors increased (both the Tex and the peak [Formula: see text] increased); two
factors decreased; time only increased (the Tex increased, but the peak [Formula:
see text] economized); and [Formula: see text] only increased (the Tex decreased,
but the peak [Formula: see text] increased). Within all patients, the
relationships between baseline variables and the post-to-pre-change ratio of the
time-slope, Tex/(peak minus resting [Formula: see text]), were investigated.
RESULTS: Compared with the two factors increased group (n=11), in the time only
increased group (n=18), the mean differences from pre-PR at peak exercise in 1)
minute ventilation [Formula: see text] (P=0.004), [Formula: see text] (P<0.0001),
and carbon dioxide output [Formula: see text] (P<0.0001) were lower, 2) [Formula:
see text]/ [Formula: see text] (P=0.034) and [Formula: see text]/ [Formula: see
text] (P=0.006) were higher, and 3) the dead space/tidal volume ratio (VD/VT) and
the dyspnea level were similar. After PR, there was no significant difference in
the ratio of the observed peak heart rate (HR) to the predicted peak HR (220 –
age [years]) between the two groups. A significant negative correlation with the
baseline time-slope (r=-0.496, P=0.002) and a positive correlation with the
baseline body mass index (BMI) (r=0.496, P=0.002) were obtained.
CONCLUSIONS: PR in COPD patients improves Tex rather than exercise tolerance,
economizing oxygen requirements, resulting in reduced ventilatory requirements
without cardiac loads followed by reduced exertional dyspnea. In addition, the
time-slope and BMI could be used to predict PR responses beforehand.

Exercise training improves characteristics of exercise oscillatory ventilation in chronic heart failure.

Panagopoulou N, Karatzanos E, Dimopoulos S, Tasoulis A, Tachliabouris
I, Vakrou S, Sideris A, Gratziou C, Nanas S

Eur J Prev Cardiol. 2017 May;24(8):825-832.
Epub 2017 Jan 1.

Comment in
Eur J Prev Cardiol. 2017 Aug;24(12 ):1283-1284.
Eur J Prev Cardiol. 2017 Aug;24(12 ):1285-1286.

Background Exercise oscillatory ventilation in chronic heart failure has been
suggested as a factor related to adverse cardiac events, aggravated prognosis and
higher mortality. Exercise training is well known to affect exercise capacity and
mechanisms of pathophysiology beneficially in chronic heart failure. Little is
known, however, about the exercise training effects on characteristics of
exercise oscillatory ventilation in chronic heart failure patients. Design and
methods Twenty (out of 38) stable chronic heart failure patients exhibited
exercise oscillatory ventilation (age 54 ± 11 years, peak oxygen uptake
15.0 ± 5.0 ml/kg per minute). Patients attended 36 sessions of high intensity
interval exercise. All patients underwent cardiopulmonary exercise testing before
and after the programme. Assessment of exercise oscillatory ventilation was based
on the amplitude of cyclic fluctuations in breathing during rest and exercise.
All values are mean ± SD. Results Exercise training reduced ( P < 0.05) the
percentage of exercise oscillatory ventilation duration (79.0 ± 13.0 to
50.0 ± 25.0%), while average amplitude (5.2 ± 2.0 to 4.9 ± 1.6 L/minute) and
length (44.0 ± 10.9 to 41.0 ± 6.7 seconds) did not change ( P > 0.05). Exercise
oscillatory ventilation patients also increased exercise capacity ( P < 0.05).
Conclusions A rehabilitation programme based on high intensity interval training
improved exercise oscillatory ventilation observed in chronic heart failure
patients, as well as cardiopulmonary efficiency and functional capacity.

Relation of heart rate recovery after exercise testing to coronary artery calcification.

Jae SY, Kurl S, Laukkanen JA, Yoon ES, Choi YH, Fernhall B,
Franklin BA

Ann Med. 2017 Aug;49(5):404-410.

BACKGROUND: We examined whether slow heart rate recovery (HRR) after exercise
testing as an estimate of impaired autonomic function is related to coronary
artery calcification (CAC), an emerging marker of coronary atherosclerosis.
METHODS: We evaluated 2088 men who participated in a health-screening program
that included measures of CAC and peak or symptom-limited cardiopulmonary
exercise testing. HRR was calculated as the difference between peak heart rate
(HR) during exercise testing and the HR at 2 min of recovery after peak exercise.
We measured CAC using multidetector computed tomography to calculate the Agatston
coronary artery calcium score. Advanced CAC was defined as a mean CAC >75th
percentile for each age group.
RESULTS: HRR was negatively correlated with CAC (r = -.14, p < .01). After
adjusting for conventional risk factors, participants in the lowest quartile of
HRR (<38 bpm) were 1.59 times (95% CI: 1.17-2.18; p < .05) more likely to have
advanced CAC than their counterparts in the highest quartile of HRR (>52 bpm).
Each 1 bpm decrease in HRR was associated with 1% increase in advanced CAC after
adjusting for potential confounders.
CONCLUSIONS: An attenuated HRR after exercise testing is associated with advanced
CAC, independent of coronary risk factors and other related hemodynamic response.
KEY MESSAGES Slow heart rate recovery (HRR) after maximal exercise testing,
indicating decreased autonomic function, is associated with an increased risk of
cardiovascular event and mortality. Slow HRR has been linked with the occurrence
of malignant ventricular arrhythmias, but it remains unclear whether slow HRR is
associated with an increased risk of coronary artery calcification (CAC), an
emerging marker of coronary atherosclerosis. An attenuated HRR after exercise
testing was associated with advanced CAC, independent of coronary risk factors
and other potential hemodynamic confounder, supporting the hypothesis that slow
HRR is related to the burden of atherosclerotic coronary artery disease.

Cardiopulmonary exercise testing and second-line pulmonary function tests to detect obstructive pattern in symptomatic smokers with borderline spirometry.

Di Marco F, Terraneo S, Job S, Rinaldo RF, Sferrazza Papa GF,
Roggi MA, Santus P, Centanni S

Respir Med. 2017 Jun;127:7-13. doi: 10.1016/j.rmed.2017.04.006. Epub 2017 Apr 10.

BACKGROUND: The need for additional research on symptomatic smokers with normal
spirometry has been recently emphasized. Albeit not meeting criteria for Chronic
obstructive pulmonary disease (COPD) diagnosis, symptomatic smokers may
experience activity limitation, evidence of airway disease, and exacerbations.
We, therefore, evaluated whether symptomatic smokers with borderline spirometry
(post-bronchodilator FEV1/FVC ratio between 5th to 20th percentile of predicted
values) have pulmonary function abnormalities at rest and ventilatory constraints
during exercise.
METHODS: 48 subjects (aged 60 ± 8 years, mean ± SD, 73% males, 16 healthy, and 17
symptomatic smokers) underwent cardiopulmonary exercise testing (CPET), body
plethysmography, nitrogen single-breath washout test (N2SBW), lung diffusion for
carbon monoxide (DLCO), and forced oscillation technique (FOT).
RESULTS: Compared to healthy subjects, symptomatic smokers showed: 1) reduced
breathing reserve (36 ± 17 vs. 49 ± 12%, P = 0.050); 2) exercise induced dynamic
hyperinflation (-0.20 ± 0.17 vs. -0.03 ± 0.21 L, P = 0.043); 3) higher residual
volume (158 ± 22 vs. 112 ± 22%, P < 0.001); 4) phase 3 slope at N2SBW (4.7 ± 2.1
vs. 1.4 ± 0.6%, P < 0.001); 5) no significant differences in DLCO and FOT
CONCLUSIONS: In smokers with borderline spirometry, CPET and second-line
pulmonary function tests may detect obstructive pattern. These subjects should be
referred for second line testing, to obtain a diagnosis, or at least to clarify
the mechanisms underlying symptoms. Whether the natural history of these patients
is similar to COPD, and they deserve a similar therapeutic approach is worth

Inter-observer reliability of preoperative cardiopulmonary exercise test interpretation: a cross-sectional study.

Abbott TEF; William Harvey Research Institute, Queen Mary University of London, London, UK; Barts Health NHS Trust, London, UK. Electronic address:
Gooneratne M; Barts Health NHS Trust, London, UK.
McNeill J; Barts Health NHS Trust, London, UK.
Lee A; William Harvey Research Institute, Queen Mary University of London, London, UK.
Levett DZH; Critical Care Research Group, Southampton NIHR Biomedical Research Centre, University Hospital Southampton-University of Southampton, Southampton, UK.
Grocott MPW; Critical Care Research Group, Southampton NIHR Biomedical Research Centre, University Hospital Southampton-University of Southampton, Southampton, UK.
Swart M; South Devon Healthcare NHS Trust, Torbay, UK.
MacDonald N; Barts Health NHS Trust, London, UK.

British Journal Of Anaesthesia [Br J Anaesth] 2018 Mar; Vol. 120 (3), pp. 475-483. Date of Electronic Publication: 2017 Nov 29.

Background: Despite the increasing importance of cardiopulmonary exercise testing (CPET) for preoperative risk assessment, the reliability of CPET interpretation is unclear. We aimed to assess inter-observer reliability of preoperative CPET.
Methods: We conducted a prospective, multi-centre, observational study of preoperative CPET interpretation. Participants were professionals with previous experience or training in CPET, assessed by a standardized questionnaire. Each participant interpreted 100 tests using standardized software. The CPET variables of interest were oxygen consumption at the anaerobic threshold (AT) and peak oxygen consumption (VO2 peak). Inter-observer reliability was measured using intra-class correlation coefficient (ICC) with a random effects model. Results are presented as ICC with 95% confidence interval, where ICC of 1 represents perfect agreement and ICC of 0 represents no agreement.
Results: Participants included 8/28 (28.6%) clinical physiologists, 10 (35.7%) junior doctors, and 10 (35.7%) consultant doctors. The median previous experience was 140 (inter-quartile range 55-700) CPETs. After excluding the first 10 tests (acclimatization) for each participant and missing data, the primary analysis of AT and VO2 peak included 2125 and 2414 tests, respectively. Inter-observer agreement for numerical values of AT [ICC 0.83 (0.75-0.90)] and VO2 peak [ICC 0.88 (0.84-0.92)] was good. In a post hoc analysis, inter-observer agreement for identification of the presence of a reportable AT was excellent [ICC 0.93 (0.91-0.95)] and a reportable VO2 peak was moderate [0.73 (0.64-0.80)].
Conclusions: Inter-observer reliability of interpretation of numerical values of two commonly used CPET variables was good (>80%). However, inter-observer agreement regarding the presence of a reportable value was less consistent.

Calculated versus Measured MVV-Surrogate Marker of Ventilatory CPET.

Colwell KL(1), Bhatia R

Med Sci Sports Exerc. 2017 Oct;49(10):1987-1992.

INTRODUCTION: Maximum voluntary ventilation (MVV), a surrogate marker of maximum
ventilatory capacity, allows for measuring ventilatory reserve during
cardiopulmonary exercise testing (CPET), which is necessary to assess ventilatory
limitation. MVV can be measured directly during a patient maneuver or indirectly
by calculating from forced expiratory volume in 1 s (FEV1 × 40). We investigated
for a potential difference between calculated MVV and measured MVV in pediatric
subjects, and which better represents maximum ventilatory capacity during CPET.

METHODS: Data were collected retrospectively from CPET conducted in pediatric
subjects for exercise-induced dyspnea from January 2014 to June 2015 at Akron
Children’s Hospital. Subjects with neuromuscular weakness, morbid obesity, and
suboptimal effort during the testing were excluded from the study.

RESULTS: Thirty-five subjects (mean ± SD, age = 13.8 ± 2.7 yr, range = 7-18 yr)
fulfilled the criteria. Measured MVV was significantly lower than calculated MVV
(89.9 ± 26.4 vs 122.4 ± 34.5 L·min; P < 0.01). The ventilatory reserve based on
measured MVV was also significantly lower than ventilatory reserve based on
calculated MVV (12.4% ± 19.6% vs 36.1% ± 13.2%; P < 0.01). Calculated MVV (as
well as ventilatory reserve based on calculated MVV) was significantly correlated
with ventilatory parameters. By contrast, no significant correlations were found
between measured MVV (or ventilatory reserve based on measured MVV) and
ventilatory parameters except for peak ventilation (peak V˙E).

CONCLUSIONS: The measured MVV was significantly lower than the calculated MVV in
our pediatric subjects. The calculated MVV was a better surrogate of maximum
ventilatory capacity as shown by significant correlation to other ventilatory
parameters during CPET.

Scaling the Oxygen Uptake Efficiency Slope for Body Size in Cystic Fibrosis.

Tomlinson OW, Barker AR, Oades PJ, Williams CA

Med Sci Sports Exerc. 2017 Oct;49(10):1980-1986.

PURPOSE: The aim of this study was to describe the relationship between body size
and oxygen uptake efficiency slope (OUES) in pediatric patients with cystic
fibrosis (CF) and healthy controls (CON), to identify appropriate scaling
procedures to adjust the influence of body size upon OUES.
METHODS: The OUES was derived using maximal and submaximal points from
cardiopulmonary exercise testing in 72 children (36 CF and 36 CON). OUES was
subsequently scaled for stature, body mass (BM), and body surface area (BSA)
using ratio-standard (Y/X) and allometric (Y/X) methods. Pearson’s correlation
coefficients were used to determine the relationship between body size and OUES.
RESULTS: When scaled using the ratio-standard method, OUES had a significant
positive relationship with stature (r = 0.54, P < 0.001) and BSA (r = 0.25, P =
0.031) and significant negative relationship with BM (r = -0.38, P = 0.016) in
the CF group. Combined allometric exponents (b) for CF and CON were stature 3.00,
BM 0.86, and BSA 1.40. A significant negative correlation was found between OUES
and stature in the CF group when scaled allometrically (r = -0.37, P = 0.027).
Nonsignificant (P > 0.05) correlations for the whole group were found between
OUES and allometrically scaled BM (CF r = -0.25, CON, r = 0.15) and BSA (CF r =
-0.27, CON r = 0.13).
CONCLUSIONS: Only allometric scaling of either BM or BSA, and not ratio-standard
scaling, successfully eliminates the influence of body size upon OUES. Therefore,
this enables a more direct comparison of the OUES between patients with CF and
healthy controls.

Cardiopulmonary exercise testing (CPET) in the United Kingdom-a national survey of the structure, conduct, interpretation and funding.

Perioper Med (Lond). 2018 Jan 26;7:2. doi: 10.1186/s13741-017-0082-3. eCollection

Reeves T, Bates S, Sharp T, Richardson K,
Bali S, Plumb J, Anderson H, Prentis J, Swart,
Levett DZH; Perioperative Exercise Testing and Training Society

Background: Cardiopulmonary exercise testing (CPET) is an exercise stress test
with concomitant expired gas analysis that provides an objective, non-invasive
measure of functional capacity under stress. CPET-derived variables predict
postoperative morbidity and mortality after major abdominal and thoracic surgery.
Two previous surveys have reported increasing utilisation of CPET preoperatively
in England. We aimed to evaluate current CPET practice in the UK, to identify who
performs CPET, how it is performed, how the data generated are used and the
funding models.
Methods: All anaesthetic departments in trusts with adult elective surgery in the
UK were contacted by telephone to obtain contacts for their pre-assessment and
CPET service leads. An online survey was sent to all leads between November 2016
and March 2017.
Results: The response rate to the online survey was 73.1% (144/197) with 68.1%
(98/144) reporting an established clinical service and 3.5% (5/144) setting up a
service. Approximately 30,000 tests are performed a year with 93.0% (80/86) using
cycle ergometry. Colorectal surgical patients are the most frequently tested
(89.5%, 77/86). The majority of tests are performed and interpreted by
anaesthetists. There is variability in the methods of interpretation and
reporting of CPET and limited external validation of results.
Conclusions: This survey has identified the continued expansion of perioperative
CPET services in the UK which have doubled since 2011. The vast majority of CPET
tests are performed and reported by anaesthetists. It has highlighted variation
in practice and a lack of standardised reporting implying a need for practice
guidelines and standardised training to ensure high-quality data to inform
perioperative decision making.

Cardiopulmonary fitness is strongly associated with body cell mass and fat-free mass

Köhler A, King R, Bahls M, Groß S, Steveling A, Gärtner S, Schipf S,  Gläser S, Völzke H, Felix SB, Markus MRP, Dörr M

Scandinavian Journal Of Medicine & Science In Sports [Scand J Med Sci Sports] 2018 Jan 18. Date of Electronic Publication: 2018 Jan 18.

Background: Peak oxygen uptake (VO2peak) is commonly indexed by total body weight (TBW) to determine cardiopulmonary fitness (CPF). This approach may lead to misinterpretation, particularly in obese subjects. We investigated the normalization of VO2peak by different body composition markers.
Methods: We analyzed combined data of 3,848 subjects (1,914 women; 49.7%), aged 20-90, from two independent cohorts of the population-based Study of Health in Pomerania (SHIP-2 and SHIP-TREND). VO2peak was assessed by cardiopulmonary exercise testing. Body cell mass (BCM), fat-free mass (FFM) and fat mass (FM) were determined by bioelectrical impedance analysis. The suitability of the different markers as a normalization variable was evaluated by taking into account correlation coefficients (r) and intercept (α-coefficient) values from linear regression models. A combination of high r and low α values was considered as preferable for normalization purposes.
Results: BCM was the best normalization variable for VO2peak (r=0.72; p=<0.001; α-coefficient=63.3 ml/min; 95%confidence interval [CI]: 3.48 to 123) followed by FFM (r=0.63; p=<0.001; α-coefficient=19.6 ml/min; 95%CI: -57.9 to 97.0). On the other hand, a much weaker correlation and a markedly higher intercept were found for TBW (r=0.42; p=<0.001; α-coefficient=579 ml/min; 95%CI: 483 to 675). Likewise, FM was also identified as a poor normalization variable (r=0.10; p=<0.001; α-coefficient=2,133; 95%CI: 2,074 to 2,191). Sex-stratified analyses confirmed the above order for the different normalization variables.
Conclusions: Our results suggest that BCM, followed by FFM, might be the most appropriate marker for the normalization of VO2peak when comparing CPF between subjects with different body shape. This article is protected by copyright. All rights reserved.