Author Archives: Paul Older

Interobserver variability of ventilatory anaerobic threshold in asymptomatic volunteers.

Kaczmarek S; Habedank D; Obst A; Dörr M; Völzke H; Gläser S; Ewert R;

Multidisciplinary Respiratory Medicine [Multidiscip Respir Med] 2019 Jun 10; Vol. 14, pp. 20. Date of Electronic Publication: 20190610 (Print Publication: 2019).

Background: The ventilatory anaerobic threshold (VO2@AT) has been used in preoperative risk assessment and rehabilitation for many years. Our aim was to determine the interobserver variability of AT using cardiopulmonary exercise (CPET) data from a large epidemiological study (SHIP, Study of Health in Pomerania).
Methods: VO2@AT was determined from CPET of 1,079 cross-sectional volunteers, according to American Heart Association guidelines. VO2@AT determinations were compared between two experienced physicians, between physicians and qualified medical assistants, and between physicians or medical assistants and software-based algorithms. For the first 522 data sets, the two physicians discussed discrepant readings to reach consensus; the remaining data sets were analyzed without consensus discussion.
Results: VO2@AT was detectable in 1,056 data sets. The physicians recorded identical VO2@AT values in 319 out of 522 cases before consensus discussion (61.1%; intraclass correlation coefficient [ICC]: 0.90; 95% confidence interval [CI]: 0.88-0.92) and in 700 out of 1,056 cases overall (66.3%; ICC: 0.95; 95% CI: 0.95-0.96), with an interobserver difference of 0 ± 8% (95% limits of agreement [LOA]: ±161 mL/min). The interobserver difference was - 2 ± 18% (95% LOA: ±418 mL/min) between a physician and medical assistants, and - 19 ± 24% to - 22 ± 26% (95% LOAs: ±719-806 mL/min) between physicians or medical assistants and software-based algorithms.
Conclusions: Experienced physicians show high agreement when determining AT in asymptomatic volunteers. However, agreement between physicians and qualified medical assistants is lower, and there is substantial deviation in AT determination between physicians or medical assistants and software-based algorithms. This must be considered when using AT as a decision tool.

Association of preoperative anaemia with cardiopulmonary exercise capacity and postoperative outcomes in noncardiac surgery: a substudy of the Measurement of Exercise Tolerance before Surgery (METS) Study.

Bartoszko J; Thorpe KE; Laupacis A; Li Ka Shing ; Wijeysundera DN;

British Journal Of Anaesthesia [Br J Anaesth] 2019 Jun 18. Date of Electronic Publication: 2019 Jun 18.

Background: Preoperative anaemia is associated with elevated risks of postoperative complications. This association may be explained by confounding related to poor cardiopulmonary fitness. We conducted a pre-specified substudy of the Measurement of Exercise Tolerance before Surgery (METS) study to examine the associations of preoperative haemoglobin concentration with preoperative cardiopulmonary exercise testing performance (peak oxygen consumption, anaerobic threshold) and postoperative complications.
Methods: The substudy included a nested cross-sectional analysis and nested cohort analysis. In the cross-sectional study (1279 participants), multivariate linear regression modelling was used to determine the adjusted association of haemoglobin concentration with peak oxygen consumption and anaerobic threshold. In the nested cohort study (1256 participants), multivariable logistic regression modelling was used to determine the adjusted association of haemoglobin concentration, peak oxygen consumption, and anaerobic threshold with the primary endpoint (composite outcome of death, cardiovascular complications, acute kidney injury, or surgical site infection) and secondary endpoint (moderate or severe complications).
Results: Haemoglobin concentration explained 3.8% of the variation in peak oxygen consumption and anaerobic threshold (P<0.001). Although not associated with the primary endpoint, haemoglobin concentration was associated with moderate or severe complications after adjustment for peak oxygen consumption (odds ratio=0.86 per 10 g L-1 increase; 95% confidence interval, 0.77-0.96) or anaerobic threshold (odds ratio=0.86; 95% confidence interval, 0.77-0.97). Lower peak oxygen consumption was associated with moderate or severe complications without effect modification by haemoglobin concentration (P=0.12).
Conclusion: Haemoglobin concentration explains a small proportion of variation in exercise capacity. Both anaemia and poor functional capacity are associated with postoperative complications and may therefore be modifiable targets for preoperative optimisation.

Reduced exercise ventilatory efficiency in Cystic Fibrosis adults with normal to moderately impaired lung function.

Di Paolo M; Teopompi E; Savi D; Crisafulli E; Longo C; Tzani P; Longo F; Ielpo A; Pisi G; Cimino G; Simmonds NJ; Neder JA; Chetta A; Palange P;

Journal Of Applied Physiology (Bethesda, Md.: 1985) [J Appl Physiol (1985)] 2019 Jun 20. Date of Electronic Publication: 2019 Jun 20.

Rationale: Despite being a hallmark and an independent prognostic factor in several cardiopulmonary diseases, ventilatory efficiency – i.e. minute ventilation/carbon dioxide output relationship (V’E/V’CO2) has never been systematically explored in cystic fibrosis (CF).
Objective: To provide a comprehensive frame of reference regarding measures of ventilatory efficiency in CF adults with normal to moderately impaired lung function and to confirm the hypothesis that V’E/V’CO2 is a sensitive marker of early lung disease.
Methods: CF patients were divided into 3 groups according to their spirometry: normal (G1), mild impairment (G2) and moderate impairment (G3) in lung function. All participants underwent incremental cardiopulmonary exercise testing on a cycle-ergometer. Lowest V’E/V’CO2 ratio (nadir) and the slope and the intercept of the linear region of the V’E/V’CO2 relationship were contrasted in a two-center retrospective analysis involving 72 CF patients and 36 healthy controls (HC).
Results: Compared to HC, CF patients had significantly higher V’E/V’CO2 nadir, slope and intercept (p<0.001, p<0.001 and p=0.049, respectively). Subgroup analysis revealed significant differences in nadir (p=0.001) and slope (p=0.012) values even between HC and G1. Dynamic hyperinflation related negatively with slope (p=0.045) and positively with intercept (p=0.001), whilst no impact on nadir was observed.
Conclusions: Ventilatory inefficiency is a clear feature of adults with CF, even among patients with normal spirometry. V’E/V’CO2 nadir seems to be the most reliable metric to describe ventilatory efficiency in CF adults. Further prospective studies are needed to clarify whether V’E/V’CO2 could represent an useful marker in the evaluation of early lung disease in CF.

Exercise training intensity determination in cardiovascular rehabilitation: Should the guidelines be reconsidered?

Hansen D; Hasselt, Belgium.; Bonné K; Alders T; Hermans A;Copermans K;Swinnen H; Maris V; Jansegers T; Mathijs W; Haenen L; Govaerts E; Reenaers V; Frederix I; Dendale P;

European Journal Of Preventive Cardiology [Eur J Prev Cardiol] 2019 Jun 20, pp. 2047487319859450. Date of Electronic Publication: 2019 Jun 20.

Aims: In the rehabilitation of cardiovascular disease patients a correct determination of the endurance-type exercise intensity is important to generate health benefits and preserve medical safety. It remains to be assessed whether the guideline-based exercise intensity domains are internally consistent and agree with physiological responses to exercise in cardiovascular disease patients.
Methods: A total of 272 cardiovascular disease patients without pacemaker executed a maximal cardiopulmonary exercise test on bike (peak respiratory gas exchange ratio >1.09), to assess peak heart rate (HRpeak), oxygen uptake (VO2peak) and cycling power output (Wpeak). The first and second ventilatory threshold (VT1 and VT2, respectively) was determined and extrapolated to %VO2peak, %HRpeak, %heart rate reserve (%HRR) and %Wpeak for comparison with guideline-based exercise intensity domains.
Results: VT1 was noted at 62 ± 10% VO2peak, 75 ± 10% HRpeak, 42 ± 14% HRR and 47 ± 11% Wpeak, corresponding to the high intensity exercise domain (for %VO2peak and %HRpeak) or low intensity exercise domain (for %Wpeak and %HRR). VT2 was noted at 84 ± 9% VO2peak, 88 ± 8% HRpeak, 74 ± 15% HRR and 76 ± 11% Wpeak, corresponding to the high intensity exercise domain (for %HRR and %Wpeak) or very hard exercise domain (for %HRpeak and %VO2peak). At best (when using %Wpeak) in only 63% and 72% of all patients VT1 and VT2, respectively, corresponded to the same guideline-based exercise intensity domain, but this dropped to about 48% and 52% at worst (when using %HRR and %HRpeak, respectively). In particular, the patient’s VO2peak related to differently elicited guideline-based exercise intensity domains (P < 0.05).
Conclusion: The guideline-based exercise intensity domains for cardiovascular disease patients seem inconsistent, thus reiterating the need for adjustment.

Comparison of prognostic values of cardiopulmonary and heart rate parameters in exercise testing in men with heart failure.

Czubaszewski L; Straburzynska-Lupa A; Migaj J; Straburzynska-Migaj E.

Cardiology Journal. 25(6):701-708, 2018. VI 1

BACKGROUND: Cardiopulmonary exercise testing (CPET) is the gold standard
in the evaluation of patients with chronic heart failure (CHF). However,
this test is relatively expensive, assessment of its results requires
experience, and in Poland it is available only in tertiary health care
centers. Many heart rate (HR) parameters taken during a standard
electrocardiographic (ECG) exercise test also shows prognostic values.
Thus, the aim of this study is to compare prognostic values of ventilatory
and HR parameters in exercise testing in CHF patients, and to find out if
HR parameters can be used instead of ventilatory in the evaluation of a
prognosis.

METHODS: One hundred thirty two men (mean age 49 +/- 11 years) with CHF
with reduced left ventricu-lar ejection fraction (< 45%) underwent a
treadmill CPET using a modified Bruce’s protocol, during which both HR and
ventilatory parameters were measured. The patients were followed for 27
+/- 13 months after CPET.

RESULTS: Mortality was 28% (n = 37). Non-survivors demonstrated
significantly shorter exercise time (342 +/- 167 vs. 525 +/- 342 s, p <
0.001), lower maximal HR (122 +/- 22 vs. 138 +/- 21 bpm, p < 0.001),
smaller difference between maximal HR and at rest (36 +/- 19 vs. 52 +/- 21
bpm, p < 0.001), and lower HR recovery rate (HRR; 16 +/- 10 vs. 24 +/- 13
bpm, p = 0.002), chronotropic index (CHI; 0.45 +/- 0.23 vs. 0.61 +/- 0.23,
p < 0.001), peak oxygen consumption (13.82 +/- 4.62 vs. 18.54 +/- 5.68
mL/kg/min, p < 0.001) and oxygen uptake efficiency slope (OUES) value
(1.56 +/- 0.58 vs. 1.94 +/- 0.63, p = 0.001), and higher ventilation to
carbon dioxide production (VE/VCO2) slope value (40.56 +/- 9.11 vs. 33.33
+/- 7.36, p < 0.001). Two parameters that showed good prognostic value and
availability in a routine CPET were chosen for receiver operating
characteristic analysis, VE/VCO2 slope and CHI, which showed cut-off
values of 35 (sensitivity 74%, specificity 71%, p < 0.001) and 64
(sensitivity 74%, specificity 68%, p < 0.001) respectively.

CONCLUSIONS: Heart rate parameters show significant prognostic values;
CHI is the best of them, however, it is weaker than VE/VCO2 slope. HR
parameters show somewhat weaker prognostic values in comparison with
ventilatory parameters, yet they may be useful in cases of CPET
unavailability.

Characteristics of cardiopulmonary exercise testing of patients with borderline mean pulmonary artery pressure.

Jiang R; Liu H; Pudasaini B; Zhang R; Xu JL; Wang L; Zhao QH; Yuan P; Guo
J; He J; Gong SG; Wu C; Wu WH; Luo CJ; Qiu HL; Jing ZC; Liu JM.

The clinical respiratory journal. 13(3):148-158, 2019 Mar. VI 1

BACKGROUND: Pulmonary hypertension patients with mean pulmonary artery
pressure (mPAP) >= 25 mm Hg had impaired cardiopulmonary exercise testing
(CPET). Borderline mean pulmonary pressures (boPAP; 21-24 mm Hg) represent
early pulmonary vasculopathy. The CPET characteristics of boPAP are a
matter of discussion. We aimed to determine the CPET profile of such
borderline hemodynamics.

METHODS: A matched case-control study was conducted on consecutive boPAP
patients at the Shanghai Pulmonary Hospital between Jan 2012 and Jan 2017.
Hemodynamics, echocardiography, the pulmonary function test (PFT) and CPET
parameters were compared between boPAP patients and normal mPAP patients
which were matched 1:1 by sex and age. Conditional logistic regression
analysis was performed to determine the efficacy of CPET in detecting
boPAP.

RESULTS: A total of 48 patients underwent RHC and CPET (24 Normal, 24
boPAP). There were no differences in the demographics, echocardiography
and PFT. BoPAP patients had significantly decreased VO2 at the anaerobic
threshold and peak VO2 /kg (858.4 +/- 246.5 mL/min vs 727.9 +/- 228.0
mL/min, P = 0.037; 21.1 +/- 6.4 mL/min/kg vs. 15.5 +/- 5.6 mL/min/kg, P =
0.001, respectively). Significant differences were not observed in
ventilation efficiency. A trend of impaired oxygen pulse and submaximal
exercise tolerance were observed in boPAP patients. Conditional logistical
regression analysis revealed the risk of boPAP increased by 2.493 (95%
confident interval: 1.388 to 4.476, P = 0.002) with every 5 mL/min/kg
decrease in peak VO2 /kg.

CONCLUSIONS: Patients with boPAP have a greater prevalence of exercise
intolerance, a trend of impaired oxygen pulse and submaximal exercise
tolerance.

Cardiopulmonary Function in Patients with Congenital Scoliosis: An Observational Study.

Lin Y, Shen J, Chen L, Yuan W, Cong H, Luo J, Kwan KYH

J Bone Joint Surg Am. 2019 Jun 19;101(12):1109-1118.

BACKGROUND: Patients with congenital scoliosis often have restrictive pulmonary
dysfunction on static pulmonary function testing (PFT). Although frequently
asymptomatic during daily activities, these patients are generally assumed to
have reduced exercise capacity. The aim of this study was to use dynamic
cardiopulmonary exercise testing (CPET) to investigate exercise capacity and its
association with spinal deformity in patients with congenital scoliosis.
METHODS: Sixty patients with congenital scoliosis who underwent preoperative
spinal radiography, PFT, and CPET were included from January 2014 to November
2017. The impact of thoracic spinal deformity and rib anomalies on pulmonary
function and physical capacity was investigated.
RESULTS: A significant deterioration in pulmonary function with increases in the
severity of the major thoracic curve was demonstrated by the forced expiratory
volume in 1 second (FEV1), forced vital capacity (FVC), and total lung capacity
(all p < 0.001). The ratio of FEV1 to FVC was similar regardless of thoracic
curve severity. A smaller tidal volume during exercise testing reflected
restrictive dysfunction in the patients with the most severe curves. CPET also
revealed a significant trend of faster breathing by patients with a severe
thoracic curve (p < 0.001). Exercise capacity indicators such as work rate (p =
0.019), heart rate (p = 0.015), and oxygen saturation (p = 0.006) were
significantly reduced only in patients with a thoracic curve of >100°. Pulmonary
dysfunction was the major contributor to exercise intolerance. Compared with mild
pulmonary dysfunction, moderate and severe dysfunction was associated with an
abnormal breathing pattern and lower work rate (p = 0.032) and peak oxygen intake
(p = 0.042), indicating worse exercise tolerance.
CONCLUSIONS: Congenital scoliosis leads to restrictive pulmonary dysfunction,
which reduces the tidal volume and forces patients to accelerate respiratory
rates during exercise. Patients with a thoracic curve of >100° are unable to
compensate and have significantly reduced exercise capacity.

Abnormal blood lactate accumulation during repeated exercise testing in myalgic encephalomyelitis/chronic fatigue syndrome

Katarina Lien , Bjørn Johansen, Marit B. Veierød, Annicke S. Haslestad, Siv K. Bøhn,
Morten N. Melsom, Kristin R. Kardel & Per O. Iversen

Physiol Rep, 7 (11), 2019, e14138,
https://doi.org/10.14814/phy2.14138

Post-exertional malaise and delayed recovery are hallmark symptoms of myalgic
encephalomyelitis/chronic fatigue syndrome (ME/CFS). Studies on
repeated cardiopulmonary exercise testing (CPET) show that previous exercise
negatively affects oxygen uptake (VO2) and power output (PO) in ME/CFS.
Whether this affects arterial lactate concentrations ([Laa]) is unknown. We
studied 18 female patients (18–50 years) fulfilling the Canadian Consensus
Criteria for ME/CFS and 15 healthy females (18–50 years) who underwent
repeated CPETs 24 h apart (CPET1 and CPET2) with [Laa] measured every
30th second. VO2 at peak exercise (VO2peak) was lower in patients than in
controls on CPET1 (P < 0.001) and decreased in patients on CPET2
(P < 0.001). However, the difference in VO2peak between CPETs did not differ
significantly between groups. [Laa] per PO was higher in patients during both
CPETs (Pinteraction < 0.001), but increased in patients and decreased in controls
from CPET1 to CPET2 (Pinteraction < 0.001). Patients had lower VO2
(P = 0.02) and PO (P = 0.002) at the gas exchange threshold (GET, the point
where CO2 production increases relative to VO2), but relative intensity
(%VO2peak) and [Laa] at GET did not differ significantly from controls on
CPET1. Patients had a reduction in VO2 (P = 0.02) and PO (P = 0.01) at
GET on CPET2, but no significant differences in %VO2peak and [Laa] at
GET between CPETs. Controls had no significant differences in VO2, PO or
%VO2peak at GET between CPETs, but [Laa] at GET was reduced on CPET2
(P = 0.008). In conclusion, previous exercise deteriorates physical performance
and increases [Laa] during exercise in patients with ME/CFS while it lowers
[Laa] in healthy subjects.

Improvement of cardiopulmonary function after minimally invasive surgical repair of pectus excavatum (Nuss procedure) in children.

Das BB; Recto MR; Yeh T;

Annals Of Pediatric Cardiology [Ann Pediatr Cardiol] 2019 May-Aug; Vol. 12 (2), pp. 77-82.

Background: Severe pectus excavatum in children may result in cardiorespiratory functional impairment; therefore, we evaluated cardiopulmonary response to exercise before and after the Nuss procedure.
Methods: Twenty-four physically active pediatric patients aged 9-18 years with severe pectus excavatum (Haller index >3.25) were included in the study. Cardiopulmonary exercise testing using treadmill and modified Bruce protocol was performed before and after the Nuss procedure.
Results: Maximal oxygen uptake and oxygen pulse improved by 40.6% (32 ± 13-45 ± 10 ml/kg/min; P = 0.0001) and 44.4% (9 ± 4-13 ± 5 ml/beat; P = 0.03), respectively, after surgical correction of pectus excavatum by Nuss procedure. Significant improvement in maximum voluntary ventilation and minute ventilation after Nuss procedure was also noted.
Conclusions: We found that, after repair of pectus excavatum by Nuss procedure, the exercise capacity as measured by maximal oxygen consumption improved significantly primarily due to increase in oxygen pulse, an indirect measurement of stroke volume.

Does exercise prescription based on estimated heart rate training zones exceed the ventilatory anaerobic threshold in patients with coronary heart disease undergoing usual-care cardiovascular rehabilitation? A United Kingdom perspective.

Pymer S; Nichols S; Birkett S; Carroll S; Ingle L;

European Journal Of Preventive Cardiology [Eur J Prev Cardiol] 2019 May 22, pp. 2047487319852711. Date of Electronic Publication: 2019 May 22.

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.