Category Archives: Publications

Making Cardiopulmonary Exercise Testing Interpretable for Clinicians.

Andonian BJ; Hardy N; Bendelac A; Polys N; Kraus WE;

Current sports medicine reports [Curr Sports Med Rep] 2021 Oct 01; Vol. 20 (10), pp. 545-552.

Abstract: Cardiopulmonary exercise testing (CPET) is a dynamic clinical tool for determining the cause for a person’s exercise limitation. CPET provides clinicians with fundamental knowledge of the coupling of external to internal respiration (oxygen and carbon dioxide) during exercise. Subtle perturbations in CPET parameters can differentiate exercise responses among individual patients and disease states. However, perhaps because of the challenges in interpretation given the amount and complexity of data obtained, CPET is underused. In this article, we review fundamental concepts in CPET data interpretation and visualization. We also discuss future directions for how to best use CPET results to guide clinical care. Finally, we share a novel three-dimensional graphical platform for CPET data that simplifies conceptualization of organ system-specific (cardiac, pulmonary, and skeletal muscle) exercise limitations. Our goal is to make CPET testing more accessible to the general medical provider and make the test of greater use in the medical toolbox.

Cardiopulmonary reserve examined with cardiopulmonary exercise testing in individuals with chronic kidney disease: a systematic review and meta-analysis.

Pella E; Boutou AK; Alexandrou ME; Bakaloudi DR; Sarridou D; Boulmpou A; Papadopoulos C; Papagianni A; Sarafidis P;

Annals of physical and rehabilitation medicine [Ann Phys Rehabil Med] 2021 Oct 08, pp. 101588.
Date of Electronic Publication: 2021 Oct 08.

Background: Patients with chronic kidney disease (CKD) often present reduced physical activity and exercise tolerance due to factors relevant to co-existing disturbances of the cardiac, nervous and muscular systems. Cardiopulmonary exercise testing (CPET) is used for clinical evaluation of exercise limitation and related symptoms (i.e., dyspnea, fatigue) in several medical fields.
Objectives: This is a systematic review and meta-analysis of studies using CPET technology to examine cardiopulmonary reserve in individuals with versus without CKD.
Methods: Literature search involved PubMed, Web of Science and Scopus databases; manual search of article references and of grey literature was also performed. Observational studies and randomized trials that used CPET for patients with CKD stage 1-5 versus controls were eligible. The primary outcome was peak oxygen uptake (VO 2 peak). The Newcastle-Ottawa Scale was used to evaluate the quality of retrieved studies.
Results: From an initial 4944 literature records, we identified 29 studies fulfilling the inclusion criteria; of these, 25 studies (2,213 participants) with complete data were included in the final meta-analysis. VO 2 peak was significantly lower in CKD patients than controls without CKD [standardized mean difference (SMD) -1.40, 95% confidence interval (CI) -1.68; -1.13)]. Values were lower for CKD than non-CKD for oxygen consumption at anaerobic threshold (SMD -1.06, 95% CI -1.34; -0.79) and maximum workload [weighted mean difference (WMD) -58.26, 95% CI 74.14; -42.38]. In 3 studies, CKD patients had higher VO 2 peak than controls with heart failure without CKD (WMD 6.60, 95% CI 3.02; 10.18). Sensitivity analyses confirmed the robustness of these findings.
Conclusions: VO 2 peak and other commonly analyzed CPET variables were lower in patients with CKD than controls, which indicates reduced functional cardiopulmonary reserve in CKD. In contrast, patients with CKD performed better than controls with heart failure without CKD. Overall, rehabilitation programs should be more widely applied to individuals with CKD.

Determinants of oxygen uptake and prognostic factors in cardiopulmonary exercise test in patients with Fontan surgery.

Cardiology in the young [Cardiol Young] 2021 Oct 04, pp. 1-4. Date of Electronic Publication: 2021 Oct 04.

Martin Talavera M;
Manso B;
Garcia de Vinuesa PG;
Cejudo Ramos P;
Rodriguez Puras MJ;
Wals Rodriguez AJ;
Garcia de Vinuesa PG,

Introduction: Cardiopulmonary exercise test (CPET) allows quantification of functional capacity of patients with Fontan. The objective of this study was to determine the role of CPET parameters in predicting a higher maximum oxygen consumption (VO2 max) and to analyse the role of CPET parameters in predicting an unfavourable outcome.
Methods: A retrospective, cross-sectional, descriptive study was carried out on 57 patients with Fontan, who had undergone incremental CPET with cycloergometer between 2010 and 2020. Determinants of VO2 max and determinants of clinical deterioration were analysed.
Results: In the univariate analysis, the variables significantly related to VO2 max were: age, sex, body mass index (BMI), years of Fontan evolution, intracardiac Fontan, oxygen consumption at anaerobic threshold (VO2AT), CO2 equivalents at anaerobic threshold (VE/VCO2) and chronotropic insufficiency. The multiple linear regression model that best fitted the relationship between VO2 max and independent variables (correlation coefficient 0.73) included sex (correlation index 3.35; p = 0.02), BMI (-0.27; p = 0.02), chronotropic failure (-2.79; p = 0.01) and VO2AT (0.92; p < 0.0001). In the univariate analysis of the prognostic CPET variables related to an unfavourable clinical situation, significance was only obtained with chronotropic insufficiency (p = 0.003). In multivariate analysis, chronotropic insufficiency maintains its association [p= 0.017, OR = 4.65 (1.3-16.5)].
Conclusions: In conclusion, together with the anthropometric parameters universally related to VO2 max, chronotropic insufficiency and VO2AT are the main determinants of functional capacity in patients with Fontan. Moreover, chronotropic insufficiency is closely related to unfavourable clinical evolution. Our data would support the intensive treatment of chronotropic insufficiency in order to improve the quality of life and the clinical situation of patients with Fontan.

Determinants of oxygen uptake and prognostic factors in cardiopulmonary exercise test in patients with Fontan surgery.

Martin Talavera M;Manso B; Seville, Spain.Cejudo Ramos P; Rodriguez Puras MJ; Wals Rodriguez AJ;
Garcia de Vinuesa PG;

Cardiology in the young [Cardiol Young] 2021 Oct 04, pp. 1-4. Date of Electronic Publication: 2021 Oct 04.

Introduction: Cardiopulmonary exercise test (CPET) allows quantification of functional capacity of patients with Fontan. The objective of this study was to determine the role of CPET parameters in predicting a higher maximum oxygen consumption (VO2 max) and to analyse the role of CPET parameters in predicting an unfavourable outcome.
Methods: A retrospective, cross-sectional, descriptive study was carried out on 57 patients with Fontan, who had undergone incremental CPET with cycloergometer between 2010 and 2020. Determinants of VO2 max and determinants of clinical deterioration were analysed.
Results: In the univariate analysis, the variables significantly related to VO2 max were: age, sex, body mass index (BMI), years of Fontan evolution, intracardiac Fontan, oxygen consumption at anaerobic threshold (VO2AT), CO2 equivalents at anaerobic threshold (VE/VCO2) and chronotropic insufficiency. The multiple linear regression model that best fitted the relationship between VO2 max and independent variables (correlation coefficient 0.73) included sex (correlation index 3.35; p = 0.02), BMI (-0.27; p = 0.02), chronotropic failure (-2.79; p = 0.01) and VO2AT (0.92; p < 0.0001). In the univariate analysis of the prognostic CPET variables related to an unfavourable clinical situation, significance was only obtained with chronotropic insufficiency (p = 0.003). In multivariate analysis, chronotropic insufficiency maintains its association [p= 0.017, OR = 4.65 (1.3-16.5)].
Conclusions: In conclusion, together with the anthropometric parameters universally related to VO2 max, chronotropic insufficiency and VO2AT are the main determinants of functional capacity in patients with Fontan. Moreover, chronotropic insufficiency is closely related to unfavourable clinical evolution. Our data would support the intensive treatment of chronotropic insufficiency in order to improve the quality of life and the clinical situation of patients with Fontan.

The association between preoperative body composition and aerobic fitness in patients scheduled for colorectal surgery.

Berkel AEM; van Dijk DPJ; Prins SN; van Meeteren NLU; Olde Damink SWM; Klaase JM; Bongers BC;

Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland
[Colorectal Dis] 2021 Oct 06. Date of Electronic Publication: 2021 Oct 06.

Aim: Though cardiopulmonary exercise testing (CPET) is considered the gold standard, the preoperative abdominal computed tomography (CT) scan might also provide information concerning preoperative aerobic fitness for risk assessment. This study aimed to investigate the association between preoperative CT-scan derived body composition variables and preoperative CPET variables of aerobic fitness in colorectal surgery.
Method: In this retrospective cohort study, CT-images at level L3 were analysed for skeletal muscle mass, skeletal muscle radiation attenuation, visceral adipose tissue (VAT) mass, and subcutaneous adipose tissue mass. Regression analyses were performed to investigate the relation between CT-scan derived body composition variables, CPET-derived aerobic fitness, and other preoperative patient-related variables. Logistic regression analysis was performed to predict a preoperative anaerobic threshold (AT) ≤11.1 mL/kg/min as cut-off for having a high risk for postoperative complications.
Results: Data from 78 patients (45 males, mean (SD) age 74.5 (6.4) years) were analysed. A correlation coefficient of 0.55 was observed between absolute AT and skeletal muscle mass index. Absolute AT (R 2 of 51.1%) was lower in patients with a lower skeletal muscle mass index, together with higher age, lower body mass, and higher American Society of Anesthesiologists (ASA) score. Higher ASA score (odds ratio 5.64; P=0.033) and higher VAT mass (odds ratio 1.02; P=0.036) were associated with an increased risk of an AT ≤11.1 mL/kg/min.
Conclusion: Body composition variables from the preoperative CT-scan were moderately associated with preoperative CPET-derived aerobic fitness. Higher ASA score and higher VAT mass were associated with an increased risk of an AT ≤11.1 mL/kg/min.

Mechanisms of Exercise Capacity Improvement after Cardiac Rehabilitation Following Myocardial Infarction Assessed with Combined Stress Echocardiography and Cardiopulmonary Exercise Testing.

Smarz K;Jaxa-Chamiec T; Zaborska B; Tysarowski M; Budaj A;

Journal of clinical medicine [J Clin Med] 2021 Sep 09; Vol. 10 (18). Date of Electronic Publication: 2021 Sep 09.

Cardiac rehabilitation (CR) is indicated in all patients after acute myocardial infarction (AMI) to improve prognosis and exercise capacity (EC). Previous studies reported that up to a third of patients did not improve their EC after CR (non-responders). Our aim was to assess the cardiac and peripheral mechanisms of EC improvement after CR using combined exercise echocardiography and cardiopulmonary exercise testing (CPET-SE). The responders included patients with an improved EC assessed as a rise in peak oxygen uptake (VO 2 ) ≥ 1 mL/kg/min. Peripheral oxygen extraction was calculated as arteriovenous oxygen difference (A-VO 2 Diff). Out of 41 patients (67% male, mean age 57.5 ± 10 years) after AMI with left ventricular ejection fraction (LVEF) ≥ 40%, 73% improved their EC. In responders, peak VO 2 improved by 27% from 17.9 ± 5.2 mL/kg/min to 22.7 ± 5.1 mL/kg/min, p < 0.001, while non-responders had a non-significant 5% decrease in peak VO 2 . In the responder group, the peak exercise heart rate, early diastolic myocardial velocity at peak exercise, LVEF at rest and at peak exercise, and A-VO 2 Diff at peak exercise increased, the minute ventilation to carbon dioxide production slope decreased, but the stroke volume and cardiac index were unchanged after CR. Non-responders had no changes in assessed parameters. EC improvement after CR of patients with preserved LVEF after AMI is associated with an increased heart rate response and better peripheral oxygen extraction during exercise.

Comparison of Methods for the Estimation of the Maximum Oxygen Uptake of Men Drug Addicts.

Wang K; Jiang H; Zhang T; Yin L; Chen X; Luo J;

Frontiers in physiology [Front Physiol] 2021 Sep 10; Vol. 12, pp. 683942.
Date of Electronic Publication: 2021 Sep 10 (Print Publication: 2021).

Background: Maximum oxygen uptake (VO 2max ) is an important respiratory physiological index of the aerobic endurance of the body, especially for special groups such as drug addicts, and it is an important indicator for assessing the cardiopulmonary function and formulating exercise prescriptions. Although the cardiopulmonary exercise test (CPX) is a classic method to directly measure VO 2max , this method is limited by factors such as cumbersome operating procedures and expensive equipment, resulting in its relatively low applicability. Recently, many studies have begun to focus on the estimation of VO 2max in different groups of people, but few studies have focused on drug addicts.
Methods: Fifteen chemically synthesized drug addicts (such as amphetamines) and Fifteen plant-derived drug addicts (such as heroin) were recruited at the Chongqing Compulsory Isolation and Drug Rehabilitation Center in China. First, the VO 2max of subjects was directly measured through the CPX. Second, after subjects were fully rested, they were required to complete the 30-s high-leg raise, 1,000-m walk, and 3-min step experiment. Finally, SPSS 21.0 software was used to perform the correlation and linear regression analysis to verify the estimated effectiveness.
Results: (1) Regardless of chemically synthesized or natural plant-derived drug addicts, the years of drug use and walking time of 1,000 m were significantly negatively correlated with VO 2max (chemically synthesized: P < 0.01 and natural plant-derived: P < 0.05), the number of 30-s high-leg raises was a significantly positive correlation with VO 2max ( P < 0.05 and P < 0.01), and the 3-min step index was significantly positively correlated with VO 2max ( P < 0.01 and P < 0.01). (2) Regression analysis shows that the 30-s high-leg lift, 1,000-m walking, and 3-min step experiment could effectively estimate the VO 2max of chemically synthesized and natural plant-derived drug addicts. (3) Multiple linear regression constructed by the years of drug use combined with the step index has the highest estimated accuracy for the VO 2max of chemically synthesized drug addicts (96.48%), while the unary regression equation established by a single step index has the highest prediction accuracy for the VO 2max of natural plant-derived addicts (94.30%).
Conclusion: The indirect measurement method could effectively estimate the VO 2max of drug addicts, but different measurement methods have certain differences in the estimation accuracy of VO 2max of different drug addicts. In the future, the physical characteristics of drug users can be fully considered, combined with more cutting-edge science and technology, to make the estimation accuracy of VO 2max closer to the real level.

Correlation of anthropometric index and cardiopulmonary exercise testing in children with pectus excavatum.

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

Respiratory physiology & neurobiology [Respir Physiol Neurobiol] 2021 Sep 21; Vol. 296, pp. 103790.
Date of Electronic Publication: 2021 Sep 21.

Background: Cardiopulmonary exercise testing (CPET) is a method used to evaluate functional impairment of patients with various diseases.
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 VO 2 and low O 2 Pulse). Mean VO 2 /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, VO 2 peak 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.