A restrictive ventilatory pattern is common in patients with univentricular heart after Fontan palliation and associated with a reduced exercise capacity and quality of life

AIM

The Fontan circulation is highly dependent on ventilation, improving pulmonary blood flow and cardiac output. A reduced ventilatory function is reported in these patients. The extent of this impairment and its relation to exercise capacity and quality of life is unknown and objective of this study.

METHODS

This multicenter retrospective/cross-sectional study included 232 patients (140 females, age 25.6 ± 10.8 years) after Fontan palliation (19.8% atrioventricular connection; 20.3% atriopulmonary connection; 59.9% total cavopulmonary connection). Resting spirometry, cardiopulmonary exercise tests, and quality-of-life assessment (SF-36 questionnaire) were performed between 2003 and 2015.

RESULTS

Overall, mean forced expiratory volume in one second (FEV₁ ) was 74.7 ± 17.8%predicted (%pred). In 59.5% of the patients, FEV₁ was <80%pred., and all of these patients had FEV₁ /forced vital capacity (FVC) > 80%, suggestive of a restrictive ventilatory pattern. Reduced FEV₁ was associated with a reduced peakVO₂ of 67.0 ± 17.6%pred. (r = 0.43, P < .0001), even if analyzed together with possible confounding factors (sex, BMI, age, years after palliation, number of interventions, scoliosis, diaphragmatic paralysis). Synergistically to exercise capacity, FEV₁ was associated to quality of life in terms of physical component summary (r = 0.30, P = .002), physical functioning (r = 0.25, P = .008), bodily pain (r = 0.22, P = .02), and general health (r = 0.16, P = .024). Lower FEV₁ was associated with diaphragmatic paralysis (P = .001), scoliosis (P = .001), higher number of interventions (P = .002), and lower BMI (P = .01). No correlation was found to ventricular morphology, type of surgeries, or other perioperative/long-term complications.

CONCLUSIONS

This study shows that the common restrictive ventilatory pattern in Fontan patients is associated with lower exercise capacity and quality of life. Risk factors are diaphragmatic paralysis, scoliosis, a high total number of interventions and low BMI.

Exercise performance and symptoms in lowlanders with COPD ascending to moderate altitude: randomized trial

Objective

To evaluate the effects of altitude travel on exercise performance and symptoms in lowlanders with COPD.

Design

Randomized crossover trial.

Setting

University Hospital Zurich (490 m), research facility in mountain villages, Davos Clavadel (1,650 m) and Davos Jakobshorn (2,590 m).

Participants

Forty COPD patients, Global Initiative for Obstructive Lung Disease (GOLD) grade 2–3, living below 800 m, median (quartiles) age 67 y (60; 69), forced expiratory volume in 1 second 57% predicted (49; 70).

Intervention

Two-day sojourns at 490 m, 1,650 m, and 2,590 m in randomized order.

Outcome measures

Six-minute walk distance (6MWD), cardiopulmonary exercise tests, symptoms, and other health effects.

Results

At 490 m, days 1 and 2, median (quartiles) 6MWD were 558 m (477; 587) and 577 m (531; 629). At 2,590 m, days 1 and 2, mean changes in 6MWD from corresponding day at 490 m were −41 m (95% CI −51 to −31) and −40 m (−53 to −27), n=40, P<0.05, both changes. At 1,650 m, day 1, 6MWD had changed by −22 m (−32 to −13), maximal oxygen uptake during bicycle exercise by −7% (−13 to 0) vs 490 m, P<0.05, both changes. At 490 m, 1,650 m, and 2,590 m, day 1, resting PaO₂ were 9.0 (8.4; 9.4), 8.1 (7.5; 8.6), and 6.8 (6.3; 7.4) kPa, respectively, P<0.05 higher altitudes vs 490 m. While staying at higher altitudes, nine patients (24%) experienced symptoms or adverse health effects requiring oxygen therapy or relocation to lower altitude.

Conclusion

During sojourns at 1,650 m and 2,590 m, lowlanders with moderate to severe COPD experienced a mild reduction in exercise performance and nearly one quarter required oxygen therapy or descent to lower altitude because of adverse health effects. The findings may help to counsel COPD patients planning altitude travel.

Registration

ClinicalTrials.gov: NCT01875133

Reliability of repeated arm-crank cardiopulmonary exercise tests in patients with small abdominal aortic aneurysm

Arm-crank ergometry may be useful in patients unable to pedal, for instance due to peripheral arterial disease. Twenty participants with small abdominal aortic aneurysm undertook two serial arm-crank tests and then a pedal test, four of whom had indeterminate anaerobic thresholds, precluding analysis. The mean (SD) peak arm and leg oxygen consumptions in 16 participants were 13.71 (2.62) ml.kg^-1 .min^-1 and 16.82 (4.44) ml.kg^-1 .min^-1 , with mean (SD) individual differences of 3.11 (2.48) ml.kg^-1 .min^-1 , p = 0.0001. The respective values at the anaerobic thresholds were 7.83 (1.58) ml O₂ .kg^-1 .min^-1 and 10.09 (3.15) ml O₂ .kg^-1 .min^-1 , with mean (SD) individual differences of 2.26 (2.34) ml O₂ .kg^-1 .min^-1 , p = 0.0001. The correlation coefficients (95%CI) for peak oxygen consumption and anaerobic threshold were 0.88 (0.62-1.0) and 0.70 (0.32-1.0). There were no significant differences in serial arm-crank tests, with intracluster correlations (95%CI) of 0.87 (0.86-0.88) and 0.65 (0.61-0.69) for peak oxygen consumption and anaerobic threshold, respectively.

Clinical impact of the lower limit of normal of FEV1/FVC on detecting chronic obstructive pulmonary disease: A follow-up study based on cross-sectional data

BACKGROUND

Criteria of obstruction that establish a diagnosis of COPD have been debated in recent years. We carried out a follow-up study to assess the impact of the new LLN reference equation for Chinese on detecting COPD compared with the traditional 0.7fixed criteria.

METHODS

We examined the prevalence and characteristics of airflow limitation for a non-child population using post-bronchodilator airflow with both age-dependent predicted lower limit of the normal value and fixed-ratio spirometric criterion. Questionnaires and spirometry were completed for all eligible subjects during the baseline examination. Participants with inconsistent diagnosis according to the two criteria, normal participants (controls) and COPD patients in stages I or II, were invited to take a cardiopulmonary exercise testing (CPET) examination and follow up for 2-4 years.

RESULTS

A total of 5448 (mean age 50.51 ± 13.2 yr) study subjects with acceptable spirometry and complete questionnaire data were included in our final analyses. COPD detection based on LLN was consistent with the GOLD 0.7 fixed-ratio in general, as 51 subjects (0.9%) were underdiagnosed, and 61 subjects (1.1%) were overdiagnosed when using LLN as the reference diagnostic criterion. The underdiagnosed subjects were younger, had more symptoms, more exposure to biofuels and worse FEV₁ than the normal group; they also demonstrated a damaged cardiopulmonary reserve capacity and significant FEV₁ decline. Except for being older, the overdiagnosed subjects differed little from the normal group.

CONCLUSIONS

Individual-dependent LLN appears to better reveal impacts on detecting airflow limitation. Participants underdiagnosed by GOLD criterion should be paid more attention.

CLINICAL TRIAL REGISTRATION

ChiCTR-ECS-13004110.

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

Background

Cardiopulmonary exercise testing (CPET) is an exercise stress test with concomitant expired gas analysis that provides an objective, non-invasive measure of functional capacity under stress. CPET-derived variables predict postoperative morbidity and mortality after major abdominal and thoracic surgery. Two previous surveys have reported increasing utilisation of CPET preoperatively in England. We aimed to evaluate current CPET practice in the UK, to identify who performs CPET, how it is performed, how the data generated are used and the funding models.

Methods

All anaesthetic departments in trusts with adult elective surgery in the UK were contacted by telephone to obtain contacts for their pre-assessment and CPET service leads. An online survey was sent to all leads between November 2016 and March 2017.

Results

The response rate to the online survey was 73.1% (144/197) with 68.1% (98/144) reporting an established clinical service and 3.5% (5/144) setting up a service. Approximately 30,000 tests are performed a year with 93.0% (80/86) using cycle ergometry. Colorectal surgical patients are the most frequently tested (89.5%, 77/86). The majority of tests are performed and interpreted by anaesthetists. There is variability in the methods of interpretation and reporting of CPET and limited external validation of results.

Conclusions

This survey has identified the continued expansion of perioperative CPET services in the UK which have doubled since 2011. The vast majority of CPET tests are performed and reported by anaesthetists. It has highlighted variation in practice and a lack of standardised reporting implying a need for practice guidelines and standardised training to ensure high-quality data to inform perioperative decision making.

Cardiopulmonary Exercise Testing

Cardiopulmonary exercise testing (CPET) is an objective assessment of exercise capacity. It has become increasingly popular in clinical, research, and athletic performance settings. CPET allows for investigation of the cardiovascular, pulmonary, and skeletal muscle systems during exercise-induced stress. The main variable of maximal oxygen uptake (VO₂max) reflects the gold standard measure of exercise capacity. This chapter will describe the method of performing a graded maximal CPET with the Vmax 229 Cardiopulmonary Exercise Testing Instrument and CardioSoft program.

The Preoperative Assessment and Optimization of Patients Undergoing Major Urological Surgery

PURPOSE OF REVIEW

Improving patient outcomes from major urological surgery requires not only advancement in surgical technique and technology, but also the practice of patient-centered, multidisciplinary, and integrated medical care of these patients from the moment of contemplation of surgery until full recovery. This review examines the evidence for recent developments in preoperative assessment and optimization that is of relevance to major urological surgery.

RECENT FINDINGS

Current perioperative medicine recommendations aim to improve the short-term safety and long-term effectiveness of surgical treatments by the delivery of multidisciplinary integrated medical care. New strategies to deliver this aim include preoperative risk stratification using a frailty index and cardiopulmonary exercise testing for patients undergoing intra-abdominal surgery (including radical cystectomy), preoperative management of iron deficiency and anemia, and preoperative exercise intervention. Proof of the utility and validity for improving surgical outcomes through advances in preoperative care is still evolving. Evidence-based developments in this field are likely to benefit patients undergoing major urological surgery, but further research targeted at high-risk patients undergoing specific urological operations is required.

Sex-specific cardiopulmonary exercise testing indices related to hemodynamics in idiopathic pulmonary arterial hypertension

Background:

Many studies have highlighted sex preponderance in idiopathic pulmonary arterial hypertension (IPAH). It is well established that there are differences in exercise capacities in the two sexes but how much of that difference reflects on disease severity or correlates to markers of severity in the two sexes is still not clear. Right heart catheterization (RHC) and cardiopulmonary exercise testing (CPET) have been widely used for assessing functional capacity, prognosis and treatment response in IPAH. We aimed to investigate the ‘sex-specific’ CPET parameters in relation to hemodynamics in IPAH.

Methods:

Data were retrieved from 30 males and 53 females [mean ± standard deviation (SD) age: 39.6 ± 17.2 and 37.5 ± 12.0] stable IPAH patients who underwent both RHC and CPET at Shanghai Pulmonary Hospital from 2010 to 2016. Univariate and forward/backward multiple stepwise regression analysis was performed to assess the prognostic value of CPET and hemodynamic parameters.

Results:

There were no significant differences in clinical variables between men and women. Peak workload, peak oxygen uptake, anaerobic threshold (AT), peak minute ventilation, carbon dioxide output, O₂ pulse and oxygen uptake efficiency slope were significantly higher in men compared with women (p < 0.05). Several CPET indexes correlated with hemodynamics. Pulmonary vascular resistance (PVR) and cardiac output (CO) were distinctly different between the sexes. Peak end-tidal partial pressure of CO₂ (P_ETCO₂) was an independent predictor of PVR elevation in all patients and in men. Peak maximum oxygen consumption (VO₂) was independently predictive of CO decline in all patients and in men. Only peak O₂ pulse was an independent predictor of increased PVR and decreased CO in women.

Conclusions:

Even after adjusting for age, body mass index and World Health Organization functional class, different CPET parameters correlated with PVR elevation and CO decline in men and women differently, which could potentially better predict severity in men and women with IPAH.

The six-minute walk test predicts cardiorespiratory fitness in individuals with aneurysmal subarachnoid hemorrhage

BACKGROUND

Peak oxygen uptake (VO_2peak) established during progressive cardiopulmonary exercise testing (CPET) is the "gold-standard" for cardiorespiratory fitness. However, CPET measurements may be limited in patients with aneurysmal subarachnoid hemorrhage (a-SAH) by disease-related complaints, such as cardiovascular health-risks or anxiety. Furthermore, CPET with gas-exchange analyses require specialized knowledge and infrastructure with limited availability in most rehabilitation facilities.

OBJECTIVES

To determine whether an easy-to-administer six-minute walk test (6MWT) is a valid clinical alternative to progressive CPET in order to predict VO_2peak in individuals with a-SAH.

METHODS

Twenty-seven patients performed the 6MWT and CPET with gas-exchange analyses on a cycle ergometer. Univariate and multivariate regression models were made to investigate the predictability of VO_2peak from the six-minute walk distance (6MWD).

RESULTS

Univariate regression showed that the 6MWD was strongly related to VO_2peak (r = 0.75, p < 0.001), with an explained variance of 56% and a prediction error of 4.12 ml/kg/min, representing 18% of mean VO_2peak. Adding age and sex to an extended multivariate regression model improved this relationship (r = 0.82, p < 0.001), with an explained variance of 67% and a prediction error of 3.67 ml/kg/min corresponding to 16% of mean VO_2peak.

CONCLUSIONS

The 6MWT is an easy-to-administer submaximal exercise test that can be selected to estimate cardiorespiratory fitness at an aggregated level, in groups of patients with a-SAH, which may help to evaluate interventions in a clinical or research setting. However, the relatively large prediction error does not allow for an accurate prediction in individual patients.

Prediction of peak oxygen uptake in children using submaximal ratings of perceived exertion during treadmill exercise

Purpose

This study assessed the utility of the Children’s Effort Rating Table (CERT) and the Eston–Parfitt (EP) Scale in estimating peak oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak) in children, during cardiopulmonary exercise testing (CPET) on a treadmill.

Methods

Fifty healthy children (n = 21 boys; 9.4 ± 0.9 years) completed a continuous, incremental protocol until the attainment of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak. Oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2) was measured continuously, and ratings of perceived exertion (RPE) were estimated at the end of each exercise stage using the CERT and the EP Scale. Ratings up to- and including RPE 5 and 7, from both the CERT (CERT 5, CERT 7) and EP Scale (EP 5, EP 7), were linearly regressed against the corresponding \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2, to both maximal RPE (CERT 10, EP 10) and terminal RPE (CERT 9, EP 9).

Results

There were no differences between measured- and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak from CERT 5, CERT 7, EP 5 and EP 7 when extrapolated to either CERT 9 or EP 9 (P > 0.05). Pearson’s correlations of r = 0.64–0.86 were observed between measured- and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak, for all perceptual ranges investigated. However, only EP 7 provided a small difference when considering the standard error of estimate, suggesting that the prediction of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak from EP 7 would be within 10 % of measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak.

Conclusions

Although robust estimates of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak may be elicited using both the CERT and EP Scale during a single CPET with children, the most accurate estimates of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak occur when extrapolating from EP 7.

Evaluation of short-term use of nocturnal nasal continuous positive airway pressure for a clinical profile and exercise capacity in adult patients with obstructive sleep apnea-hypopnea syndrome

BACKGROUND AND AIM

The obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common chronic respiratory disease, characterized by repetitive complete or partial collapse of the upper airway during sleep. The clinical spectrum extends between stoppage of breathing, snoring, daytime somnolence, and fatigue, to serious cardiovascular disease, stroke, metabolic syndrome, increased morbidity, and mortality. We aim to evaluate the short-term use of nasal continuous positive airway pressure (nCPAP) therapy for the clinical profile and exercise capacity of patients with OSAHS.

PATIENT SELECTION

Twenty patients diagnosed with moderate-to-severe OSAHS were enrolled in the study (study group - 15; clinically and PSG-matched control group - 5).

MATERIALS AND METHODS

Each patient was clinically evaluated for sleep-related symptoms, and also assessed with spirometry, the six-minute walk test (6MWT), and a symptom-limited incremental cardiopulmonary exercise test (CPET). The study group patients were administered nCPAP therapy for eight hours each night for four weeks, while the control group patients were just observed. They were re-assessed after four weeks and the data were statistically analyzed between the two groups.

RESULTS

The study group patients showed a significant (P- < 0.05) improvement in the OSAHS symptoms-the Epworth sleepiness score, six-minute walk distance; duration of exercise, power output, peak oxygen uptake, anaerobic threshold, diastolic blood pressure, dyspnea, and fatigue-in comparison with the control group patients. The improvement in exercise capacity following nCPAP therapy was attributed to the relief of disabling the OSAHS symptoms and improved cardiovascular, ventilator, and musculoskeletal functions.

CONCLUSION

All OSAHS patients must be treated with nCPAP.

Effect of lung transplantation on heart rate response to exercise

OBJECTIVES

To evaluate if patients have a change in percent of predicted heart rate reserve used at peak exercise (%HRR) after lung transplantation, even at matching workloads.

BACKGROUND

Lung disease of obstructive, restrictive, and mixed types may be associated with an autonomic imbalance. Lung transplantation may improve the effects of pulmonary disease on cardiac function. However, the effect of lung transplantation on heart rate responses during exercise has not been investigated in detail.

METHODS

Retrospective review of patients who underwent lung transplantation. Pre and post transplant cardiopulmonary exercise tests were reviewed.

RESULTS

The %HRR significantly improved by a median of 37% (p < 0.001) following lung transplantation. When matching workloads were analyzed, the %HRR also decreased from a median of 36% to 24% (p < 0.001).

CONCLUSIONS

Corresponding to an increase in peak exercise capacity, percentage of heart rate reserve used improves significantly after lung transplantation, even at matching workloads, indicating a likely improvement in autonomic modulation.

Physical activity impairment in depressed COPD subjects

BACKGROUND

Limited exercise tolerance is a cardinal clinical feature in COPD. Depression and COPD share some clinical features, such as reduced physical activity and impaired nutritional status. The aim of the present study was to evaluate maximum and daily physical activities and the nutritional status of COPD patients affected or not by depression.

METHODS

In 70 COPD out-patients, daily and maximum physical activities were assessed by multisensor accelerometer armband, 6-min walk test, and cardiopulmonary exercise test. Mental status, metabolic/muscular status, and systemic inflammation were evaluated using the Hospital Anxiety and Depression Scale, by bioelectrical impedance analysis, and with regard to fibrinogen/C-reactive protein, respectively.

RESULTS

Depressed subjects (27% of the sample) showed a similar level of respiratory functional impairment but a higher level of shortness of breath and a worse quality of life compared to non-depressed subjects (P < .05). Specifically, they displayed a physical activity impairment consisting of a reduced number of steps per day, a lower peak of oxygen consumption, an early anaerobic threshold, and a reduced distance in the 6-min walk test (P < .05) but the same nutritional status compared to non-depressed subjects. In the multivariate analysis, a reduced breathing reserve, obesity, and a higher level of shortness of breath, but not depression, were found to be independent factors associated with a reduced daily number of steps.

CONCLUSIONS

Our study found that depressed COPD patients have a reduced daily and maximum exercise capacity compared to non-depressed patients. This further suggests the potential utility of screening for depression in COPD.

Ventilatory efficiency slope correlates with functional capacity, outcomes, and disease severity in pediatric patients with pulmonary hypertension

BACKGROUND

Cardiopulmonary exercise testing is widely used in a variety of cardiovascular conditions. Ventilatory efficiency slope can be derived from submaximal exercise testing. The present study sought to evaluate the relationship between ventilatory efficiency slope and functional capacity, outcomes, and disease severity in pediatric patients with pulmonary hypertension.

METHODS

Seventy six children and young adults with a diagnosis of pulmonary hypertension (PH) performed 258 cardiopulmonary exercise tests from 2001 to 2011. Each individual PH test was matched to a control test. Ventilatory efficiency slope was compared to traditional measures of functional capacity and disease severity including WHO functional classification, peak oxygen consumption, and invasive measures of pulmonary arterial pressures and pulmonary vascular resistance.

RESULTS

Ventilatory efficiency slope was significantly higher in patients with pulmonary arterial hypertension, with an estimated increase of 7.2 for each increase in WHO class (p<0.0001), compared with normal control subjects (38.9 vs. 30.9, p<0.001). Ventilatory efficiency slope correlated strongly with invasive measures of disease severity including pulmonary vascular resistance index (r =0.61), pulmonary artery pressure (r =0.58), mean pulmonary artery pressure/mean aortic pressure ratio (r =0.52), and peak VO2 (r=-0.58). Ventilatory efficiency slope in 12 patients with poor outcomes (9 death, 3 lung transplant), was significantly elevated compared to patients who did not (51.1 vs. 37.9, p<0.001).

CONCLUSIONS

Ventilatory efficiency slope correlates well with invasive and noninvasive markers of disease severity including peak VO2, WHO functional class, and catheterization variables in pediatric patients with PH. Ventilatory efficiency slope may be a useful noninvasive marker for disease severity.

The interface of hypothalamic-pituitary-adrenocortical axis and circulating brain natriuretic peptide in prediction of cardiopulmonary performance during physical stress

Brain natriuretic peptide (NT-pro-BNP) was implicated in the regulation of hypothalamic-pituitary-adrenocortical (HPA) responses to psychological stressors. However, HPA axis activation in different physical stress models and its interface with NT-pro-BNP in the prediction of cardiopulmonary performance is unclear. Cardiopulmonary test on a treadmill was used to assess cardiopulmonary parameters in 16 elite male wrestlers (W), 21 water polo player (WP) and 20 sedentary age-matched subjects (C). Plasma levels of NT-pro-BNP, cortisol and adrenocorticotropic hormone (ACTH) were measured using immunoassay sandwich technique, radioimmunoassay and radioimmunometric techniques, respectively, 10min before test (1), at beginning (2), at maximal effort (3), at 3rdmin of recovery (4). In all groups, NT-pro-BNP decreased between 1 and 2; increased from 2 to 3; and remained unchanged until 4. ACTH increased from 1 to 4, whereas cortisol increased from 1 to 3 and stayed elevated at 4. In all groups together, ΔNT-pro-BNP2/1 predicted peak oxygen consumption (B=37.40, r=0.38, p=0.007); cortisol at 3 predicted heart rate increase between 2 and 3 (r=-0.38,B=-0.06, p=0.005); cortisol at 2 predicted peak carbon-dioxide output (B=2.27, r=0.35, p<0.001); ΔACTH3/2 predicted peak ventilatory equivalent for carbon-dioxide (B=0.03, r=0.33, p=0.003). The relation of cortisol at 1 with NT-pro-BNP at 1 and 3 was demonstrated using logistic function in all the participants together (for 1/cortisol at 1 B=63.40, 58.52; r=0.41, 0.34; p=0.003, 0.013, respectively). ΔNT-pro-BNP2/1 linearly correlated with ΔACTH4/3 in WP and W (r=-0.45, -0.48; p=0.04, 0.04, respectively). These results demonstrate for the first time that HPA axis and NT-pro-BNP interface in physical stress probably contribute to integrative regulation of cardiopulmonary performance.

Cardiovascular abnormalities in Klinefelter syndrome

BACKGROUND

Several epidemiological studies have demonstrated an increased mortality from cardiovascular causes in patients with Klinefelter Syndrome (KS). Little information is available about the nature of the underlying cardiovascular abnormalities. Aim of the study was to investigate exercise performance, left ventricular architecture and function, vascular reactivity, and carotid intima-media thickness in a group of patients with KS.

MATERIALS AND METHODS

Sixty-nine patients with KS and 48 age-matched controls participated in our population-controlled study. Forty-eight Klinefelter subjects were on testosterone treatment at the time of the investigation while 21 were naive and underwent a complete Doppler echocardiographic examination, a cardiopulmonary exercise test as well as a vascular study including measures of carotid intima-media thickness and endothelial function with flow-mediated dilation of the brachial artery. Patients with KS on testosterone therapy (n=48) were also matched against a population of men with treated secondary hypogonadism (n=21).

RESULTS

Patients with KS exhibited a wide array of cardiovascular abnormalities including left ventricular diastolic dysfunction, reduced maximal oxygen consumption (p<0.01), increased intima-media thickness (p<0.05) (-34% and +42% vs. controls, respectively) and a high prevalence of chronotropic incompetence (55% of patients, p<0.01). No significant difference was found between treated and untreated KS in variance with men treated for secondary hypogonadism.

CONCLUSION

Left ventricular diastolic dysfunction, impaired cardiopulmonary performance, chronotropic incompetence, and increased intima-media thickness suggest that cardiovascular abnormalities are a common finding in KS that is not reversed by testosterone replacement therapy and may represent the pathophysiological underpinnings of the increased risk of dying from heart disease.

Influence of body mass on risk prediction during cardiopulmonary exercise testing in patients with chronic heart failure

INTRODUCTION

Peak oxygen uptake (VO2) during a maximal exercise test is used to stratify patients with chronic heart failure (CHF) and is usually corrected for body mass.

OBJECTIVE

To explore the influence of body mass on risk prediction during treadmill cardiopulmonary exercise testing (CPET) in patients with CHF.

METHODS

A total of 411 patients with suspected CHF (mean [± SD] age 64±12 years; 81% male; mean left ventricular ejection fraction 39±6%) underwent symptom-limited, maximal CPET on a treadmill. Patients were categorized as normal weight, overweight or obese based on body mass index.

RESULTS

One hundred fifteen patients died during a median follow-up period of 8.7±2.3 years in survivors. In the univariable analysis, peak VO2 adjusted for body mass (χ(2)=41.4) and unadjusted (χ(2)=40.2) were similar for predicting all-cause mortality. Peak VO2 adjusted for body mass showed marginally higher χ(2) values in normal weight, overweight and obese categories than unadjusted values. Anaerobic threshold had similar prognostic power regardless of whether it was corrected for body mass (χ(2)=22.4 and χ(2)=24.4), with no difference between the two in any of the subgroups separately. In all patients, unadjusted ventilation (VE)/carbon dioxide production (VCO2) slope (χ(2)=40.6) was a stronger predictor of all-cause mortality than body mass adjusted values (χ(2)=32.8), and unadjusted values remained stronger in normal weight, overweight and obese subgroups.

CONCLUSION

Correcting peak VO2 for body mass slightly improves risk prediction, especially in obese patients with CHF. The adjustment of other CPET-derived variables including anaerobic threshold and VE/VCO2 slope for body mass appears to provide less prognostic value.