Cycle Ergometer Cardiopulmonary Exercise Testing Research Articles

Cardiac hemodynamics phenotypes and individual responses to training in coronary heart disease patients.

In patients with coronary heart disease (CHD), individualized exercise training (ET) programs are strongly recommended to optimize peak oxygen uptake ( O2peak) improvement and prognosis. However, the cardiac hemodynamic factors responsible for a positive response to training remain unclear. The aim of this study was to compare cardiac hemodynamic changes after an ET program in responder (R) versus non-responder (NR) CHD patients. A total of 72 CHD patients completed a 3-month ET program and were assessed by cycle ergometer cardiopulmonary exercise test (CPET: O2peak assessment) with impedance cardiography (ICG) for hemodynamic measurements before and after training. Cardiac hemodynamics (e.g., CO, CI, SV, ESV, EDV, and SVR) were measured by ICG during CPET. The R and NR groups were classified using the median change in O2peak (>the median for R and ≤the median for NR). In the R group, O2peak (+17%, p < 0.001), CO, CI, SV, and HR increased by 17%, 17%, 13%, and 5%, respectively (p < 0.05) after the training program. In the NR group, O2peak, CO, CI, and SV increased by 0.5%, 5%, 8%, and 6%, respectively (p < 0.01). The SVR decreased in both groups (-19% in R and -11% in NR, p < 0.001). Among CHD patients, the R group showed a better improvement in peak cardiac output via an increase in peak stroke volume and heart rate and a reduced systemic vascular resistance than the NR group. Different cardiac phenotype adaptations and clinical individual responses were identified in CHD patients according to the aerobic fitness responder's status.

Cardiopulmonary Exercise Testing Provides Prognostic Information in Advanced Cystic Fibrosis Lung Disease.

Rationale: Cardiopulmonary exercise testing (CPET) provides prognostic information in cystic fibrosis (CF); however, its prognostic value for patients with advanced CF lung disease is unknown. Objectives: To determine the prognostic value of CPET on the risk of death or lung transplant (LTX) within 2 years. Methods: We retrospectively collected data from 20 CF centers in Asia, Australia, Europe, and North America on patients with a forced expiratory volume in 1 second (FEV1) ⩽ 40% predicted who performed a cycle ergometer CPET between January 2008 and December 2017. Time to death/LTX was analyzed using mixed Cox proportional hazards regression. Conditional inference trees were modeled to identify subgroups with increased risk of death/LTX. Results: In total, 174 patients (FEV1, 30.9% ± 5.8% predicted) were included. Forty-four patients (25.5%) died or underwent LTX. Cox regression analysis adjusted for age, sex, and FEV1 revealed percentage predicted peak oxygen uptake ([Formula: see text]o2peak) and peak work rate (Wpeak) as significant predictors of death/LTX: adjusted hazard ratios per each additional 10% predicted were 0.60 (95% confidence interval, 0.43-0.90; P = 0.008) and 0.60 (0.48-0.82; P < 0.001). Tree-structured regression models, including a set of 11 prognostic factors for survival, identified Wpeak to be most strongly associated with 2-year risk of death/LTX. Probability of death/LTX was 45.2% for those with a Wpeak ⩽ 49.2% predicted versus 10.9% for those with a Wpeak > 49.2% predicted (P < 0.001). Conclusions: CPET provides prognostic information in advanced CF lung disease, and Wpeak appears to be a promising marker for LTX referral and candidate selection.

Reference Values of Cardiopulmonary Exercise Test Parameters in the Contemporary Paediatric Population

BackgroundThe evaluation of health status by cardiopulmonary exercise test (CPET) has shown increasing interest in the paediatric population. Our group recently established reference Z-score values for paediatric cycle ergometer VO2max, applicable to normal and extreme weights, from a cohort of 1141 healthy children. There are currently no validated reference values for the other CPET parameters in the paediatric population. This study aimed to establish, from the same cohort, reference Z-score values for the main paediatric cycle ergometer CPET parameters, apart from VO2max.ResultsIn this cross-sectional study, 909 healthy children aged 5–18 years old underwent a CPET. Linear, quadratic, and polynomial mathematical regression equations were applied to identify the best CPET parameters Z-scores, according to anthropometric parameters (sex, age, height, weight, and BMI). This study provided Z-scores for maximal CPET parameters (heart rate, respiratory exchange ratio, workload, and oxygen pulse), submaximal CPET parameters (ventilatory anaerobic threshold, VE/VCO2 slope, and oxygen uptake efficiency slope), and maximum ventilatory CPET parameters (tidal volume, respiratory rate, breathing reserve, and ventilatory equivalent for CO2 and O2).ConclusionsThis study defined paediatric reference Z-score values for the main cycle ergometer CPET parameters, in addition to the existing reference values for VO2max, applicable to children of normal and extreme weights. Providing Z-scores for CPET parameters in the paediatric population should be useful in the follow-up of children with various chronic diseases. Thus, new paediatric research fields are opening up, such as prognostic studies and clinical trials using cardiopulmonary fitness outcomes.Trial registration NCT04876209—Registered 6 May 2021—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04876209.

COVID-19 and athletes: Endurance sport and activity resilience study-CAESAR study.

Background: The COVID-19 pandemic and imposed restrictions influenced athletic societies, although current knowledge about mild COVID-19 consequences on cardiopulmonary and physiologic parameters remains inconclusive. This study aimed to assess the impact of mild COVID-19 inflection on cardiopulmonary exercise test (CPET) performance among endurance athletes (EA) with varied fitness level. Materials and Methods: 49 EA (nmale = 43, nfemale = 6, mean age = 39.94 ± 7.80yr, height = 178.45cm, weight = 76.62kg; BMI = 24.03kgm-2) underwent double treadmill or cycle ergometer CPET and body analysis (BA) pre- and post-mild COVID-19 infection. Mild infection was defined as: (1) without hospitalization and (2) without prolonged health complications lasting for >14days. Speed, power, heart rate (HR), oxygen uptake (VO2), pulmonary ventilation, blood lactate concentration (at the anaerobic threshold (AT)), respiratory compensation point (RCP), and maximum exertion were measured before and after COVID-19 infection. Pearson's and Spearman's r correlation coefficients and Student t-test were applied to assess relationship between physiologic or exercise variables and time. Results: The anthropometric measurements did not differ significantly before and after COVID-19. There was a significant reduction in VO2 at the AT and RCP (both p < 0.001). Pre-COVID-19 VO2 was 34.97 ± 6.43mlkg·min-1, 43.88 ± 7.31mlkg·min-1 and 47.81 ± 7.81mlkg·min-1 respectively for AT, RCP and maximal and post-COVID-19 VO2 was 32.35 ± 5.93mlkg·min-1, 40.49 ± 6.63mlkg·min-1 and 44.97 ± 7.00mlkg·min-1 respectively for AT, RCP and maximal. Differences of HR at AT (p < 0.001) and RCP (p < 0.001) was observed. The HR before infection was 145.08 ± 10.82bpm for AT and 168.78 ± 9.01bpm for RCP and HR after infection was 141.12 ± 9.99bpm for AT and 165.14 ± 9.74bpm for RCP. Time-adjusted measures showed significance for body fat (r = 0.46, p < 0.001), fat mass (r = 0.33, p = 0.020), cycling power at the AT (r = -0.29, p = 0.045), and HR at RCP (r = -0.30, p = 0.036). Conclusion: A mild COVID-19 infection resulted in a decrease in EA's CPET performance. The most significant changes were observed for VO2 and HR. Medical Professionals and Training Specialists should be aware of the consequences of a mild COVID-19 infection in order to recommend optimal therapeutic methods and properly adjust the intensity of training.

Abstract 10985: Cardiopulmonary Assessment of COVID-19 Survivors Stratified by Acute Disease Severity and Post-Acute Symptoms

Introduction: Studies have demonstrated a reduction in peak oxygen consumption (VO 2 ) post-acute COVID-19. We sought to determine the association between acute COVID-19 severity, post-acute symptoms and peak VO 2 after recovery. Methods: This study analyzed data from patients who recovered from COVID-19 and underwent cardiopulmonary exercise testing (CPET) as part of prospective studies in 5 centers across UK and Europe. Patients were asked to report current symptoms. Peak VO 2 , lung volumes, gas exchange, ventilatory efficiency, heart rate and O 2 pulse were measured in a standard symptom-limited incremental cycle ergometer CPET. Results: Among 417 patients examined 136±63 days after recovery from COVID-19, 164 (39%) were female. Mean age was 56.9±13.3 years. The spectrum of acute COVID-19 severity included critical (N=47; 11.3%), severe (180; 43.2%), moderate (75; 18.0%) and mild (115; 27.5%) illness. The most common post-acute symptom was dyspnea (200; 48%), followed by muscle pain (173; 41%). Mean peak respiratory exchange ratio was 1.13±0.1, and did not vary across acute disease severity or post-acute symptom status. There was no significant difference in peak VO 2 as % from predicted in mild to critical acute disease: 84.0±2.1%, 91.4±2.6%, 82.9±1.7% and 83.7±3.2%, respectively (p=0.06). Patients with dyspnea or muscle pain had each lower peak VO 2 as % from predicted, compared to patients free of the specific symptom (81.3±21.2% vs. 88.1±22.9%, p=0.002 and 78.6±19.1% vs. 88.2±22.0%, p&lt;0.0001, respectively). Both dyspnea and muscle pain were each associated with significantly lower peak heart rate and peak O 2 pulse, as well as lower lung volumes and gas exchange capacity, compared to patients free of the specific symptom. Conclusions: Common post-acute COVID-19 symptoms, and not acute disease severity, are associated with lower peak VO2 in CPET. Parameters related to both cardiac and pulmonary function seem to play a role in this reduced physical performance.

Differences between Treadmill and Cycle Ergometer Cardiopulmonary Exercise Testing Results in Triathletes and Their Association with Body Composition and Body Mass Index.

Cardiopulmonary exercise testing (CPET) is the method of choice to assess aerobic fitness. Previous research was ambiguous as to whether treadmill (TE) and cycle ergometry (CE) results are transferrable or different between testing modalities in triathletes. The aim of this paper was to investigate the differences in HR and VO2 at maximum exertion between TE and CE, at anaerobic threshold (AT) and respiratory compensation point (RCP) and evaluate their association with body fat (BF), fat-free mass (FFM) and body mass index (BMI). In total, 143 adult (n = 18 female), Caucasian triathletes had both Tr and CE CPET performed. The male group was divided into <40 years (n = 80) and >40 years (n = 45). Females were aged between 18 and 46 years. Body composition was measured with bioelectrical impedance before tests. Differences were evaluated using paired t-tests, and associations were evaluated in males using multiple linear regression (MLR). Significant differences were found in VO2 and HR at maximum exertion, at AT and at RCP between CE and TE testing, in both males and females. VO2AT was 38.8 (±4.6) mL/kg/min in TE vs. 32.8 (±5.4) in CE in males and 36.0 (±3.6) vs. 32.1 (±3.8) in females (p < 0.001). HRAT was 149 (±10) bpm in TE vs. 136 (±11) in CE in males and 156 (±7) vs. 146 (±11) in females (p < 0.001). VO2max was 52 (±6) mL/kg/min vs. 49 (±7) in CE in males and 45.3 (±4.9) in Tr vs. 43.9 (±5.2) in females (p < 0.001). HRmax was 183 (±10) bpm in TE vs. 177 (±10) in CE in males and 183 (±9) vs. 179 (±10) in females (p < 0.001). MLR showed that BMI, BF and FFM are significantly associated with differences in HR and VO2 at maximum, AT and RCP in males aged >40. Both tests should be used independently to achieve optimal fitness assessments and further training planning.

Normative cardiopulmonary exercise data for endurance athletes: the Cardiopulmonary Health and Endurance Exercise Registry (CHEER).

Accurate interpretation of cardiopulmonary exercise testing (CPET) relies on age, gender, and exercise modality-specific reference values. To date, clinically applicable CPET reference values derived from a source population of endurance athletes (EAs) have been lacking. The purpose of this study was to generate CPET reference values for use in the clinical assessment of EA. Prospective data accrued during the clinical care of healthy EA were used to derive CPET reference values and to develop novel equations for V˙O2peak. The performance of these equations was compared to the contemporary standard of care equations and assessed in a discrete EA validation cohort. A total of 272 EA (age = 42 ± 15 years, female = 31%, V˙O2peak = 3.6 ± 0.83 L/min) met inclusion criteria and comprised the derivation cohort. V˙O2peak prediction equations derived from general population cohorts described a modest amount of V˙O2peak variability [R2 = 0.58-0.70, root mean square error (RMSE) = 0.46-0.54 L/min] but were mis-calibrated (calibration-in-the-large = 0.45-1.18 L/min) among EA leading to significant V˙O2peak underestimation. Newly derived, externally validated V˙O2peak prediction equations for EA that included age, sex, and height for both treadmill (R2 = 0.74, RMSE = 0.42 L/min) and cycle ergometer CPET (Cycle: R2 = 0.69, RMSE = 0.42 L/min) demonstrated improved accuracy. Commonly used V˙O2peak prediction equations derived from general population cohorts perform poorly among competitive EA. Newly derived CPET reference values including novel V˙O2peak prediction equations may improve the clinical utility of CPET in this rapidly growing patient population.

Diastolic Dysfunction Is Associated with Impaired Cardiopulmonary Exercise Performance in Sickle Cell Disease

▪Background:Left ventricular diastolic dysfunction is associated with increased mortality in sickle cell disease (SCD). Diffuse myocardial fibrosis is common in patients with SCD and is associated with diastolic dysfunction. Measurement of functional capacity by cardiopulmonary exercise test (CPET) has prognostic value in several cardiac diseases. Exercise impairment is common in SCD, but the causes and correlates are not well understood. Diastolic dysfunction is associated with a shorter 6-minute walk distance in SCD, but the effect of diastolic dysfunction and myocardial fibrosis on CPET has not been studied before.Methods:As part of a prospective study to characterize the cardiomyopathy of SCD (NCT02410811), children and adults with SCD underwent cardiac MRI (CMR), echocardiography and cycle ergometer CPET. Diffuse myocardial fibrosis was assessed by CMR-based measurement of extracellular volume fraction (ECV) from pre- and post-gadolinium T1 maps. Cardiac chamber sizes and cardiac performance were evaluated using CMR, and diastolic parameters were measured by echocardiography. Patients were classified to have diastolic dysfunction if they had left atrial enlargement and abnormalities in two diastolic parameters (E/e' ratio and e'). The following measures were recorded during CPET: percent predicted VO2 at maximum exercise (VO2 max) and ventilation efficiency (VE/VCO2 slope at maximum exercise (VE/VCO2 max). Reduced exercise capacity was defined by VO2 max <80% and classified as mild (VO2max 60-80%) or moderate to severe (VO2 max <60%).Results:Fifteen patients with SCD have completed the study (age range 8-38 years). No adverse events were reported within one month of CPET. Only one patient did not reach maximum exercise due to muscular fatigue. Fourteen patients (93%) had reduced exercise capacity; four of them (28%) had mild impairment and 10 (71%) had moderate to severe impairment. Four patients had diastolic dysfunction and none had systolic dysfunction. Patients with diastolic dysfunction had lower exercise capacity compared to patients with normal diastolic function as measured by lower VO2 max (46.6 ± 5.9% vs 59.2 ± 11.5%; p=0.02). The z-score of the left ventricular lateral E/e' ratio, a diastolic measure that reflects left ventricular filling pressure, negatively correlated with the maximal exercise capacity VO2 max (r=-0.57, p=0.02) and positively with worse ventilation efficiency measured by VE/VCO2 max (r=0.61, p=0.01), indicating an association between diastolic dysfunction and worse exercise performance. We did not find an association between ECV and exercise capacity. Hemoglobin concentration was moderately associated with VO2 max (r=0.37) but this association was not statistically significance (p=0.09).Conclusion:Diastolic dysfunction is associated with poor exercise capacity assessed by CPET in patients with SCD. Myocardial diastolic dysfunction may be one of the causes of impaired exercise capacity in SCD. Strategies to prevent or delay the acquisition of diastolic dysfunction to improve exercise capacity and long-term outcomes in SCD should be explored. DisclosuresQuinn:Global Blood Therapeutics: Research Funding.

Normative Values for Cardiopulmonary Exercise Stress Testing Using Ramp Cycle Ergometry in Children and Adolescents

To provide sex, age, and race specific reference values for ramp cycle ergometer cardiopulmonary exercise test (CPET) in children in the US. Retrospective review was conducted of all cardiopulmonary CPET data from our Exercise Physiology Laboratory on healthy children and adolescents (6-18years) with body mass index between the 5th and 95th percentiles and structurally normal hearts who performed a ramp cycle ergometry stress test between 1999 and 2015. Twenty-eight exercise variables were included: peak oxygen consumption, oxygen consumption at ventilatory anaerobic threshold, peak work rate, resting and peak heart rate and blood pressure, resting pulmonary function testing, and ventilatory responses to progressive exercise using breath-by-breath gas exchange. Owing to the nonlinear association between CPET results and age, fractional polynomials were used in the mixed-effects regression models to describe the sex- and age-specific normative values with 95% CIs, after adjusting for race and body mass index. We analyzed data on 1829 children (average age, 13.6±2.6years; 52% male). After 12years of age, males generally had higher peak values for aerobic capacity and work rate. There were progressive increases with age for both sexes in resting pulmonary function and ventilatory response to exercise, peak aerobic and work rate, and oxygen pulse. Notably, there was an age-related decrease in ventilatory equivalents of oxygen and carbon dioxide at the ventilatory anaerobic threshold. Future research using prospective, inclusive, and statistically planned cohorts with standardized laboratory approaches and confirmed interoperability should be considered as a focus for validating normative pediatric CPET values in the future.

Characterization of the blood pressure response during cycle ergometer cardiopulmonary exercise testing in black and white men : Data from the Fitness Registry and Importance of Exercise: A National Database (FRIEND).

It has been established that blacks have higher overall incidence and prevalence of hypertension compared to their white counterparts. However, the maximum blood pressure (BP) response of blacks to exercise has not been characterized. A total of 5996 apparently healthy men from the Fitness Registry and Importance of Exercise: A National Database (FRIEND) who underwent maximum cardiopulmonary exercise tests on a cycle ergometer were included in this analysis. Of these participants, 1245 (21%) self-identified as black while the remaining 4751 (79%) identified as white. All subjects had a respiratory exchange ratio (RER) of ≥1.0 and had no reports of cardiovascular or pulmonary disease. Systolic BP (BP) response to exercise was indexed according to increase in workload (SBP/MET-slope). Both racial groups were subdivided into age groups by decade. Black men had higher peak SBP and higher SBP/MET-slopes compared to white men across all age groups (p < 0.001). Resting SBP was not different between blacks and whites except within the 18-29-year age group. The differences in peak SBP and SBP/MET-slope between age and race groups indicate that black men have an exaggerated BP response to exercise irrespective of resting BP values. Further investigation is warranted to determine the underlying mechanisms responsible and clinical implications for this exaggerated BP response to exercise.

The effect of test modality on dynamic exercise biomarkers in children, adolescents, and young adults.

Cardiopulmonary exercise testing (CPET) modalities, treadmill (TM), and cycle ergometer (CE), influence maximal gas exchange and heart rate (HR) responses. Little is known regarding CPET modality effect on submaximal biomarkers during childhood and adolescence. Ninety‐four healthy participants (7–34 y.o., 53% female) performed TM and CE CPET to address two major gaps: (1) the effect of modality on submaximal CPET biomarkers, and (2) estimation of work rate in TM CPET. Breath‐by‐breath gas exchange enabled calculation of linear regression slopes such as V˙O2/ΔHR and ΔV˙E/ΔV˙CO2. Lean body mass (LBM) was measured with dual X‐ray absorptiometry. We tested a novel TM CPET estimate of work rate based on TM velocity2, incline, and body mass (VIM). Like the linear relationship between V˙O2 and work rate in CE CPET, V˙O2 increased linearly with TM VIM. TM ΔV˙O2/ΔHR was highly correlated with CE (r = 0.92), and each increased substantially with LBM (P < 0.0001 for TM and CE). ΔV˙O2/ΔHR was to a small (~8.7%) but significant extent larger in TM (1.6 mL/min/beat, P = 0.04). In contrast, TM and CE ΔV˙E/ΔV˙CO2 decreased significantly with LBM, supporting earlier observations from CE CPET. For both CE and TM, males had significantly higher ΔV˙O2/ΔHR but lower ΔV˙E/ΔV˙CO2 than females. Novel TM CPET biomarkers such as ΔVIM/ΔHR and ∆V˙O2/ΔVIM paralleled effects of LBM observed in CE CPET. TM and CE CPET submaximal biomarkers are not interchangeable, but similarly reflect maturation during critical periods. CPET analysis that utilizes data actually measured (rather than estimated) may improve the clinical value of TM and CE CPET.

Diastolic dysfunction is associated with exercise impairment in patients with sickle cell anemia.

Left ventricular diastolic dysfunction (DD) is an independent risk factor for mortality in sickle cell anemia (SCA) and is associated with increased extracellular volume (ECV) on cardiac MRI (CMR). Exercise impairment is common in SCA, but its causes and prognostic value are not well understood. To study the effects of DD and ECV on cardiopulmonary exercise test (CPET) in patients with SCA. As part of a prospective study to characterize the cardiomyopathy of SCA (NCT02410811), 20 children and adults with SCA underwent CMR, echocardiography, and cycle ergometer CPET (age range 8-43years). Maximum exercise was reached in 18 patients and 17 (94%) had reduced exercise capacity (%predicted VO2 less than 80%). Six patients had DD and none had systolic dysfunction. Patients with DD had lower exercise capacity compared to patients with normal diastolic function (%predicted VO2 48.2±9.1%vs. 61.2±11.7%; P=0.01). The z-score of left ventricular lateral E/e' ratio, which is a marker of DD, was negatively associated with %predicted VO2 (r=-0.61, P=0.01). All patients with moderate-to-severe exercise impairment (%predicted VO2 <60%) had lateral E/e' z-score>2. In a multivariate analysis, lateral E/e' z-score was independently associated with %predicted VO2 (P=0.02). All participants had elevated ECV but the degree of elevation was not associated with exercise parameters. Left ventricular DD is associated with decreased exercise capacity in SCA. Interventions to prevent or delay DD could improve exercise capacity, quality of life, and long-term outcomes in SCA.

Cardiorespiratory optimal point during exercise testing as a predictor of all-cause mortality

Introduction and AimThe cardiorespiratory optimal point (COP) is a novel index, calculated as the minimum oxygen ventilatory equivalent (VE/VO2) obtained during cardiopulmonary exercise testing (CPET). In this study we demonstrate the prognostic value of COP both independently and in combination with maximum oxygen consumption (VO2max) in community-dwelling adults. MethodsMaximal cycle ergometer CPET was performed in 3331 adults (66% men) aged 40-85 years, healthy (18%) or with chronic disease (81%). COP cut-off values of <22, 22-30, and >30 were selected based on the log-rank test. Risk discrimination was assessed using COP as an independent predictor and combined with VO2max. ResultsMedian follow-up was 6.4 years (7.1% mortality). Subjects with COP >30 demonstrated increased mortality compared to those with COP <22 (hazard ratio [HR] 6.86, 95% confidence interval [CI] 3.69-12.75, p<0.001). Multivariate analysis including gender, age, body mass index, and the forced expiratory volume in 1 s/vital capacity ratio showed adjusted HR for COP >30 of 3.72 (95% CI 1.98-6.98; p<0.001) and for COP 22-30 of 2.15 (95% CI 1.15-4.03, p<0.001). Combining COP and VO2max data further enhanced risk discrimination. ConclusionsCOP >30, either independently or in combination with low VO2max, is a good predictor of all-cause mortality in community-dwelling adults (healthy or with chronic disease). COP is a submaximal prognostic index that is simple to obtain and adds to CPET assessment, especially for adults unable or unwilling to achieve maximal exercise.

Cardiorespiratory optimal point during exercise testing as a predictor of all-cause mortality

Introduction and AimThe cardiorespiratory optimal point (COP) is a novel index, calculated as the minimum oxygen ventilatory equivalent (VE/VO2) obtained during cardiopulmonary exercise testing (CPET). In this study we demonstrate the prognostic value of COP both independently and in combination with maximum oxygen consumption (VO2max) in community-dwelling adults. MethodsMaximal cycle ergometer CPET was performed in 3331 adults (66% men) aged 40-85 years, healthy (18%) or with chronic disease (81%). COP cut-off values of <22, 22-30, and >30 were selected based on the log-rank test. Risk discrimination was assessed using COP as an independent predictor and combined with VO2max. ResultsMedian follow-up was 6.4 years (7.1% mortality). Subjects with COP >30 demonstrated increased mortality compared to those with COP <22 (hazard ratio [HR] 6.86, 95% confidence interval [CI] 3.69-12.75, p<0.001). Multivariate analysis including gender, age, body mass index, and the forced expiratory volume in 1 s/vital capacity ratio showed adjusted HR for COP >30 of 3.72 (95% CI 1.98-6.98; p<0.001) and for COP 22-30 of 2.15 (95% CI 1.15-4.03, p<0.001). Combining COP and VO2max data further enhanced risk discrimination. ConclusionsCOP >30, either independently or in combination with low VO2max, is a good predictor of all-cause mortality in community-dwelling adults (healthy or with chronic disease). COP is a submaximal prognostic index that is simple to obtain and adds to CPET assessment, especially for adults unable or unwilling to achieve maximal exercise.

Influence of age in estimating maximal oxygen uptake.

ObjectiveTo assess the influence of age on the error of estimate (EE) of maximal oxygen uptake (VO2max) using sex and population specific-equations in cycle ergometer exercise testing, since estimated VO2 max is associated with a substantial EE, often exceeding 20%, possibly due to intrinsic variability of mechanical efficiency.Methods1850 adults (68% men), aged 18 to 91 years, underwent maximal cycle ergometer cardiopulmonary exercise testing. Cardiorespiratory fitness (CRF) was assessed relative to sex and age [younger (18 to 35 years), middle-aged (36 to 60 years) and older (> 60 years)]. VO2max [mL·(kg·min)−1] was directly measured by assessment of gas exchange and estimated using sex and population specific-equations. Measured and estimated values of VO2max and related EE were compared among the three age- and sex-specific groups.ResultsDirectly measured VO2max of men and women were 29.5 ± 10.5 mL·(kg·min)−1 and 24.2 ± 9.0 mL·(kg·min)−1 (P < 0.01). EE [mL·(kg·min)−1] and percent errors (%E) for men and women had similar values, 0.5 ± 3.2 and 0.4 ± 2.9 mL·(kg·min)−1, and −0.8 ± 13.1% and −1.7 ± 15.4% (P > 0.05), respectively. EE and %E for each age-group were, respectively, for men: younger = 1.9 ± 4.1 mL·(kg·min)−1 and 3.8 ± 10.5%, middle-aged = 0.6 ± 3.1 mL·(kg·min)−1 and 0.4 ± 10.3%, older = −0.2 ± 2.7 mL·(kg·min)−1 and −4.2 ± 16.6% (P < 0.01); and for women: younger = 1.2 ± 3.1 mL·(kg·min)−1 and 2.7 ± 10.0%, middle-aged = 0.7 ± 2.8 mL·(kg·min)−1 and 0.5 ± 11.1%, older = -0.8 ± 2.3 mL·(kg·min)−1 and −9.5 ± 22.4% (P < 0.01).ConclusionVO2max were underestimated in younger age-groups and were overestimated in older age groups. Age significantly influences the magnitude of the EE of VO2max in both men and women and should be considered when CRF is estimated using population specific equations, rather than directly measured.

Utility of Equations to Estimate Peak Oxygen Uptake and Work Rate From a 6-Minute Walk Test in Patients With COPD in a Clinical Setting.

To determine the utility of equations that use the 6-minute walk test (6MWT) results to estimate peak oxygen uptake ((Equation is included in full-text article.)o2) and peak work rate with chronic obstructive pulmonary disease (COPD) patients in a clinical setting. This study included a systematic review to identify published equations estimating peak (Equation is included in full-text article.)o2 and peak work rate in watts in COPD patients and a retrospective chart review of data from a hospital-based pulmonary rehabilitation program. The following variables were abstracted from the records of 42 consecutively enrolled COPD patients: measured peak (Equation is included in full-text article.)o2 and peak work rate achieved during a cycle ergometer cardiopulmonary exercise test, 6MWT distance, age, sex, weight, height, forced expiratory volume in 1 second, forced vital capacity, and lung diffusion capacity. Estimated peak (Equation is included in full-text article.)o2 and peak work rate were estimated from 6MWT distance using published equations. The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work to prescribe aerobic exercise intensities of 60% and 80% was calculated. Eleven equations from 6 studies were identified. Agreement between estimated and measured values was poor to moderate (intraclass correlation coefficients = 0.11-0.63). The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work rate to prescribe exercise intensities of 60% and 80% of measured values ranged from mean differences of 12 to 35 and 16 to 47 percentage points, respectively. There is poor to moderate agreement between measured peak (Equation is included in full-text article.)o2 and peak work rate and estimations from equations that use 6MWT distance, and the use of the estimated values for prescription of aerobic exercise intensity would result in large error. Equations estimating peak (Equation is included in full-text article.)o2 and peak work rate are of low utility for prescribing exercise intensity in pulmonary rehabilitation programs.

Cardiopulmonary exercise testing before liver surgery.

Cardiopulmonary exercise testing (CPET) assessed "poorer" fitness correlates with poorer outcomes in blinded studies. Whether this correlation will persist when CPET is utilized to stratify care as part of a multi-modal enhanced recovery after surgery (ERAS) program is unclear. This study examined whether CPET variables were associated with postoperative morbidity in patients undergoing hepatectomy within an ERAS program. Data were prospectively collected on patients undergoing elective hepatectomy between October 2009 and April 2011. The relationships between CPET derived variables; postoperative complications and length of stay were investigated. Of 267 patients undergoing surgery, 197 had undergone standard cycle ergometer CPET. The relative oxygen uptake [VO2 (ml kg(-1) min(-1))] and ventilatory equivalent of CO2 (VE/VCO2) at the anaerobic threshold (AT) were not associated with complications or length of stay. Greater absolute oxygen uptake at AT [VO2 at AT (L min(-1) )] was associated with early hospital discharge [OR 2.16 (95% CI 1.18-3.96), P = 0.013] on multivariable analysis. When CPET is used to delineate perioperative management a low relative oxygen uptake [VO2 (ml kg(-1) min(-1) )] at the AT does not place patients at significantly higher risk of postoperative complications. This suggests CPET assessed "poor" fitness should not be used as a barrier to surgical intervention.

Comparison of the modified shuttle walk test and cardiopulmonary exercise test in sarcoidosis

Dyspnoea and exercise intolerance are common in sarcoidosis and are often poorly correlated with resting lung function. Measurement of peak exercise capacity is likely to be helpful in assessing and monitoring disease. The aim of this study was to compare the modified shuttle walk test (MSWT) to cardiopulmonary exercise test (CPET) as a measure of peak exercise capacity in sarcoidosis. Thirty-three (17 male, mean age 48 years) patients with sarcoidosis completed a standardized exponential exercise protocol cycle ergometer CPET and a single corridor MSWT in random order. Subjects has a mean forced expiratory volume in 1 s (FEV1) 2.4 L (75.7%predicted), forced vital capacity (FVC) 3.43 L (88.7%predicted) and diffusing capacity for carbon monoxide (DLCO) 20.3 mL/min/mm Hg (71.4%predicted). There was a strong correlation between MSWT distance and peak oxygen uptake (VO2) during CPET (r = 0.87; P < 0.0001), and between maximum heart rate during MSWT and CPET (r = 0.82; P < 0.0001). There was a moderate correlation between FEV1 , FVC and DLCO with MSWT distance (r = 0.55, r = 0.61, r = 0.61, respectively; all P < 0.001) and with peak VO2 (r = 0.62, r = 0.63, r = 0.62, respectively; all P < 0.0001). Peak VO2 achieved during CPET strongly correlated with MSWT distance. MSWT is a measure of peak exercise capacity in sarcoidosis that does not require equipment and can be readily available in the clinic.

Exercise Testing in Survivors of Intensive Care—Is There a Role for Cardiopulmonary Exercise Testing?

Abstract Purpose The aims of this study were to assess the feasibility of cardiopulmonary exercise testing (CPET) for the early assessment of cardiorespiratory fitness in general adult intensive care unit (ICU) survivors and to characterize the pathophysiology of exercise limitation in this population. Methods Fifty general ICU survivors (ventilated for ≥5 days) performed a maximal cycle ergometer CPET within 6 weeks of hospital discharge. Health-related quality of life was measured by the Medical Outcome Study Short Form 36 version 2.0 questionnaire. Results Fifty patients (median age, 57 years; median Acute Physiology And Chronic Health Evaluation II score, 16) completed a CPET 24 ± 14 days after hospital discharge with no adverse events. Significant exercise limitation was present with peak V o 2 56% ± 16% predicted and anaerobic threshold (AT) 41% ± 13% of peak predicted V o 2. Prospectively stratified subgroup comparison showed that patients ventilated for 14 days or more had a significantly lower AT and peak V o 2 than those ventilated for 5 to 14 days (AT: 9.6 vs 11.7 mL/kg per minute O2, P = .009; peak V o 2: 12.9 vs 15.3 mL/kg per minute O2, P = .022). At peak exercise, heart rate reserve was 25% ± 14%, breathing reserve was 47% ± 19%, and the respiratory exchange ratio was 0.96 ± 0.11. Ventilatory equivalents for CO2 (Eq co 2) were 39 ± 9. Conclusions Significant exercise limitation is evident in patients who have had critical illness. Etiology of exercise limitation appears multifactorial, with general deconditioning and muscle weakness as major contributory factors. Early CPET appears a practical method of assessing exercise capacity in ICU survivors. Cardiopulmonary exercise testing could be used to select patients who may benefit most from a targeted physical rehabilitation program, aid in exercise prescription, and help assess the response to intervention.

Exercise testing in survivors of intensive care—is there a role for cardiopulmonary exercise testing?

PurposeThe aims of this study were to assess the feasibility of cardiopulmonary exercise testing (CPET) for the early assessment of cardiorespiratory fitness in general adult intensive care unit (ICU) survivors and to characterize the pathophysiology of exercise limitation in this population. MethodsFifty general ICU survivors (ventilated for ≥5 days) performed a maximal cycle ergometer CPET within 6 weeks of hospital discharge. Health-related quality of life was measured by the Medical Outcome Study Short Form 36 version 2.0 questionnaire. ResultsFifty patients (median age, 57 years; median Acute Physiology And Chronic Health Evaluation II score, 16) completed a CPET 24 ± 14 days after hospital discharge with no adverse events. Significant exercise limitation was present with peak Vo2 56% ± 16% predicted and anaerobic threshold (AT) 41% ± 13% of peak predicted Vo2. Prospectively stratified subgroup comparison showed that patients ventilated for 14 days or more had a significantly lower AT and peak Vo2 than those ventilated for 5 to 14 days (AT: 9.6 vs 11.7 mL/kg per minute O2, P = .009; peak Vo2: 12.9 vs 15.3 mL/kg per minute O2, P = .022). At peak exercise, heart rate reserve was 25% ± 14%, breathing reserve was 47% ± 19%, and the respiratory exchange ratio was 0.96 ± 0.11. Ventilatory equivalents for CO2 (Eqco2) were 39 ± 9. ConclusionsSignificant exercise limitation is evident in patients who have had critical illness. Etiology of exercise limitation appears multifactorial, with general deconditioning and muscle weakness as major contributory factors. Early CPET appears a practical method of assessing exercise capacity in ICU survivors. Cardiopulmonary exercise testing could be used to select patients who may benefit most from a targeted physical rehabilitation program, aid in exercise prescription, and help assess the response to intervention.