Category Archives: Publications

The relationship between heart rate and VO2 in moderate-to-severe asthmatics.

Rodrigues Mendes FA; Teixeira RN; Martins MA; Cukier A; Stelmach R; Medeiros WM;Carvalho CRF;

The Journal Of Asthma: Official Journal Of The Association For The Care Of Asthma [J Asthma] 2019 Jul 03, pp. 1-9.

Objective: The main purpose of this study was to evaluate whether the %HRR-%VO2R relationship and %HRR-VO2peak relationship are affected in patients with moderate or severe asthma and whether airway obstruction and aerobic capacity influence these relationships.
Methods: A linear regression was calculated using the paired %VO2R-%HRR and %VO2peak-%HRR for 93 subjects with asthma. The mean slope and y-intercept were calculated and compared with the line of identity (y-intercept = 0, slope = 1) for all patients and subgroups for the following conditions: low and normal VO2peak and low and normal FEV1.
Results: The slope and intercepts of %VO2R-%HRR were similar to the line of identity for all groups (p > 0.05), and the regressions between %HRR and %VO2peak did not coincide with the line of identity for all groups (p < 0.05). There were no associations between the intercepts of the %HRR-VO2peak and the %HRR-%VO2R relationship with the VO2peak (p > 0.05) or FEV1 (p > 0.05).
Conclusions: This is the first study to confirm a constant equivalence between %HRR and %VO2R in outpatients with moderate or severe asthma. Our data also suggest that the relationship between %HRR and %VO2peak is unreliable. These results support the use of %HRR in relation to %VO2R to estimate exercise intensity in this population, independently of the pulmonary function and fitness level.

The developing athlete’s heart: a cohort study in young athletes transitioning through adolescence.

Bjerring AW; Landgraff HE; Stokke TM; Murbræch K; Leirstein S; Aaeng A; Brun H; Haugaa KH;Hallén J; Edvardsen T; Sarvari SI;

European Journal Of Preventive Cardiology [Eur J Prev Cardiol] 2019 Jul 08, pp. 2047487319862061

Background: Athlete’s heart is a term used to describe physiological changes in the hearts of athletes, but its early development has not been described in longitudinal studies. This study aims to improve our understanding of the effects of endurance training on the developing heart.
Methods: Cardiac morphology and function in 48 cross-country skiers were assessed at age 12 years (12.1 ± 0.2 years) and then again at age 15 years (15.3 ± 0.3 years). Echocardiography was performed in all subjects including two-dimensional speckle-tracking strain echocardiography and three-dimensional echocardiography. All participants underwent cardiopulmonary exercise testing at both ages 12 and 15 years to assess maximal oxygen uptake and exercise capacity.
Results: Thirty-one (65%) were still active endurance athletes at age 15 years and 17 (35%) were not. The active endurance athletes had greater indexed maximal oxygen uptake (62 ± 8 vs. 57 ± 6 mL/kg/min, P < 0.05) at follow-up. There were no differences in cardiac morphology at baseline. At follow-up the active endurance athletes had greater three-dimensional indexed left ventricular end-diastolic (84 ± 11 mL/m2 vs. 79 ± 10 mL/m2, P < 0.05) and end-systolic volumes (36 ± 6 mL/m2 vs. 32 ± 3 mL/m2, P < 0.05). Relative wall thickness fell in the active endurance athletes, but not in those who had quit (-0.05 ΔmL/m2 vs. 0.00 mL/m2, P = 0.01). Four active endurance athletes had relative wall thickness above the upper reference values at baseline; all had normalised at follow-up.
Conclusion: After an initial concentric remodelling in the pre-adolescent athletes, those who continued their endurance training developed eccentric changes with chamber dilatation and little change in wall thickness. Those who ceased endurance training maintained a comparable wall thickness, but did not develop chamber dilatation.

Factors associated with exercise capacity in patients with a systemic right ventricle.

Gavotto A; Abassi H; Rola M; Serrand C; Picot MC; Iriart X; Thambo JB; Iserin L; Ladouceur M; Bredy C; Amedro P;

International Journal Of Cardiology [Int J Cardiol] 2019 Jun 13. Date of Electronic Publication: 2019 Jun 13.

Background: Systemic right ventricle (RV) is a rare and complex congenital heart disease (CHD). Patients with a systemic RV present with a significant decrease of their exercise capacity. We aimed at identifying clinical and paraclinical factors associated with maximum oxygen uptake (VO2max) in adults with a systemic RV.
Methods: This multicentre cross-sectional study was performed in 2017 in three French tertiary care CHD centres. Adult patients with a D-transposition of the great artery (d-TGA) or a congenitally corrected TGA (cc-TGA) were included. Demographic, clinical, laboratory and imaging data were collected. Univariate and multivariate analyses were performed to identify predictors of impaired VO2max, as measured by cardiopulmonary exercise test (CPET).
Results: A total of 111 patients were included in the study (85% d-TGA, median age 37.2 ± 8.2 years). Most patients presented with impaired physical capacity (mean VO2max of 23.3 ± 6.9 ml/kg/min, representing 68.4 ± 16.6% of predicted values) and ventilatory anaerobic threshold (VAT) impaired (mean VAT of 32.7 ± 10.9% of the predicted values). In univariate analysis, VO2max correlated with professional status, NYHA functional class, BNP level, the type of systemic RV, decreased RV function values in cardiac imaging, the severity of tricuspid regurgitation, the presence of a pacemaker or an implantable defibrillator, the VAT, the maximum load, and the maximal heart rate during exercise. In multivariate analysis, the VO2max remained associated with the NYHA functional class. The final multivariate model explained 49% of the variability of VO2max.
Conclusion: NYHA functional class and RV function are predictors of impaired exercise capacity in adult patients with systemic RV.

Amino Acid-Based Metabolic Profile Provides Functional Assessment and Prognostic Value for Heart Failure Outpatients.

Wang CH; Cheng ML; Liu MH; Fu TC;

Disease Markers [Dis Markers] 2019 May 19; Vol. 2019, pp. 8632726. Date of Electronic Publication: 20190519 (Print Publication: 2019).

Functional capacity is a crucial parameter correlated with outcomes. The currently used New York Heart Association functional classification (NYHA Fc) system has substantial limitations, leading to inaccurate classification. This study investigated whether amino acid-based assessment on metabolic status provides an objective way to assess functional capacity and prognosis in heart failure (HF) outpatients. Plasma concentrations of histidine, ornithine, and phenylalanine (HOP) were measured on 890 HF outpatients to assess metabolic status by calculating the HOP score. Cardiopulmonary exercise testing (CPET) was performed in 387 patients to measure metabolic equivalents (MET) in order to define the functional class based on MET (MET Fc). Patients were followed for composite events (death/HF-related rehospitalization) up to one year. We found only 47% concordance between the MET Fc and NYHA Fc. HOP scores worked better than NYHA Fc for discriminating patients with MET Fc II and III from those with MET Fc I, with the optimal cutoff value set at 8.8. HOP scores ≥ 8.8 were associated with risk factors for composite events in different kinds of HF populations and were a powerful predictor of composite events in univariate analysis. In multivariable analysis, HOP scores ≥ 8.8 remained a powerful event predictor, independent of other risk factors. Kaplan-Meier curves revealed that HOP scores of ≥8.8 stratified patients at higher risk of composite events in a variety of HF populations. In conclusion, amino acid-based assessment of metabolic status correlates with functional capacity in HF outpatients and provides prognostic value for a variety of HF populations.

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.