Endothelial function in patients with COPD: an updated systematic review of studies using flow-mediated dilatation.

INTRODUCTION: Cardiovascular disease is a significant cause of morbidity and mortality in COPD. Endothelial dysfunction is suggested to be involved in cardiovascular disease pathogenesis, and multiple studies report endothelial dysfunction in COPD. This article summarized the current knowledge on endothelial function in COPD patients. AREAS COVERED: Databases were screened until November 2022 for studies using ultrasound-based flow-mediated dilation in patients with stable COPD. Pooled effect sizes were calculated using random effects model. Meta-regression analyses assessed the effects of demographic and clinical variables. EXPERT OPINION: 34 studies were identified (1365 COPD patients; 617 controls). Pooled analysis demonstrated an impaired endothelial-dependent (-2.33%; 95%CI -3.30/-1.35; p < 0.001) and endothelial-independent dilation (-3.11%; 95%CI -5.14/-1.08; p = 0.003) in COPD patients when compared to non-COPD controls. Meta-regression identified that higher age, worse severity of airflow obstruction, and current smoking were significantly associated with impaired endothelial function. Studies evaluating the effects of pharmacological and non-pharmacological interventions on endothelial function in COPD patients demonstrated conflicting results.

Improving diagnosis and risk stratification across the ejection fraction spectrum: the Maastricht Cardiomyopathy registry.

AIMS: Heart failure (HF) represents a clinical syndrome resulting from different aetiologies and degrees of heart diseases. Among these, a key role is played by primary heart muscle disease (cardiomyopathies), which are the combination of multifactorial environmental insults in the presence or absence of a known genetic predisposition. The aim of the Maastricht Cardiomyopathy registry (mCMP-registry; NCT04976348) is to improve (early) diagnosis, risk stratification, and management of cardiomyopathy phenotypes beyond the limits of left ventricular ejection fraction (LVEF). METHODS AND RESULTS: The mCMP-registry is an investigator-initiated prospective registry including patient characteristics, diagnostic measurements performed as part of routine clinical care, treatment information, sequential biobanking, quality of life and economic impact assessment, and regular follow-up. All subjects aged ≥16 years referred to the cardiology department of the Maastricht University Medical Center (MUMC+) for HF-like symptoms or cardiac screening for cardiomyopathies are eligible for inclusion, irrespective of phenotype or underlying causes. Informed consented subjects will be followed up for 15 years. Two central approaches will be used to answer the research questions related to the aims of this registry: (i) a data-driven approach to predict clinical outcome and response to therapy and to identify clusters of patients who share underlying pathophysiological processes; and (ii) a hypothesis-driven approach in which clinical parameters are tested for their (incremental) diagnostic, prognostic, or therapeutic value. The study allows other centres to easily join this initiative, which will further boost research within this field. CONCLUSIONS: The broad inclusion criteria, systematic routine clinical care data-collection, extensive study-related data-collection, sequential biobanking, and multi-disciplinary approach gives the mCMP-registry a unique opportunity to improve diagnosis, risk stratification, and management of HF and (early) cardiomyopathy phenotypes beyond the LVEF limits.

Clustering based on comorbidities in patients with chronic heart failure: an illustration of clinical diversity.

AIMS: It is increasingly recognized that the presence of comorbidities substantially contributes to the disease burden in patients with heart failure (HF). Several reports have suggested that clustering of comorbidities can lead to improved characterization of the disease phenotypes, which may influence management of the individual patient. Therefore, we aimed to cluster patients with HF based on medical comorbidities and their treatment and, subsequently, compare the clinical characteristics between these clusters. METHODS AND RESULTS: A total of 603 patients with HF entering an outpatient HF rehabilitation programme were included [median age 65 years (interquartile range 56-71), 57% ischaemic origin of cardiomyopathy, and left ventricular ejection fraction 35% (26-45)]. Exercise performance, daily life activities, disease-specific health status, coping styles, and personality traits were assessed. In addition, the presence of 12 clinically relevant comorbidities was recorded, based on targeted diagnostics combined with applicable pharmacotherapies. Self-organizing maps (SOMs; www.viscovery.net) were used to visualize clusters, generated by using a hybrid algorithm that applies the classical hierarchical cluster method of Ward on top of the SOM topology. Five clusters were identified: (1) a least comorbidities cluster; (2) a cachectic/implosive cluster; (3) a metabolic diabetes cluster; (4) a metabolic renal cluster; and (5) a psychologic cluster. Exercise performance, daily life activities, disease-specific health status, coping styles, personality traits, and number of comorbidities were significantly different between these clusters. CONCLUSIONS: Distinct combinations of comorbidities could be identified in patients with HF. Therapy may be tailored based on these clusters as next step towards precision medicine. The effect of such an approach needs to be prospectively tested.

Kinetic analyses as a tool to examine physiological exercise responses in a large sample of patients with COPD.

Kinetic features such as oxygen uptake (V̇o2) mean response time (MRT), and gains of V̇o2, carbon dioxide output (V̇co2), and minute ventilation (V̇e) can describe physiological exercise responses during a constant work rate test of patients with chronic obstructive pulmonary disease (COPD). This study aimed to establish simple guidelines that can identify COPD patients for whom kinetic analyses are (un)likely to be reliable and examined whether slow V̇o2 responses and gains of V̇o2, V̇co2, and V̇e are associated with ventilatory, cardiovascular, and/or physical impairments. Kinetic features were examined for 265 COPD patients [forced expiratory volume in 1 s (FEV1): 54 ± 19%predicted] who performed a constant work rate test (duration > 180 s) with breath-by-breath measurements of V̇o2, V̇co2, and V̇e. Negative/positive predictive values were used to define cutoff values of relevant clinical variables below/above which kinetic analyses are (un)likely to be reliable. Kinetic feature values were unreliable for 21% (= 56/265) of the patients and for 79% (= 19/24) of the patients with a peak work rate (WRpeak)< 45 W. Kinetic feature values were considered reliable for 94% (= 133/142) of the patients with an FEV1 > 1.3 L. For patients exhibiting reliable kinetic feature values, V̇o2 MRT was associated with ventilatory (e.g., FEV1 %predicted: P < 0.001; r = -0.35) and physical (e.g., V̇o2peak %predicted: P = 0.009; r = -0.18) impairments. Gains were mainly associated with cardiac function and ventilatory constraints, representing both response efficiency and limitation. Kinetic analyses are likely to be unreliable for patients with a WRpeak < 45 W. Whereas gains enrich analyses of physiological exercise responses, V̇o2 MRT shows potential to serve as a motivation-independent, physiological indicator of physical performance.NEW & NOTEWORTHY A constant work rate test that is standardly performed during a prerehabilitation assessment is unable to provide reliable kinetic feature values for chronic obstructive pulmonary disease (COPD) patients with a peak work rate below 45 W. For patients suffering from less severe impairments, kinetic analyses are a powerful tool to examine physiological exercise responses. Especially oxygen uptake mean response time can serve as a motivation-independent, physiological indicator of physical performance in patients with COPD.

Determinants of functional, peak and endurance exercise capacity in people with chronic obstructive pulmonary disease.

BACKGROUND: Exercise limitation in COPD is multi-factorial. The contribution of cardiac function to exercise capacity is not clear. METHODS: Potential determinants of the different constructs of exercise capacity (functional, peak and endurance exercise capacity using the 6-minute walk distance (6MWD), peak oxygen uptake (VO2peak) and peak work load, and sub-maximal constant work rate test (CWRT) cycle time, respectively) were analysed. RESULTS: Data were collected in 516 people with COPD (56% male, age (mean ±â€¯SD) 64 ±â€¯9 years, FEV1% predicted 49 ±â€¯20%). Participants had reduced exercise capacity (6MWD 424 ±â€¯124 m, 67 ±â€¯18% predicted; VO2peak 1090 ±â€¯414 ml/min, 66 ±â€¯30% predicted; peak work load 70 ±â€¯34 watts, 56 ±â€¯27% predicted; CWRT cycle time (median (IQR)) 225 (169-328) seconds). Cardiac function measures, including echocardiography and N-terminal pro-brain natriuretic peptide level, were independently significantly correlated with exercise capacity. In multiple regression analyses adjusted for age and gender, 72% (p < 0.001) of the 6MWD variance could be explained, with the timed up-and-go test accounting for 32% of the variance. For VO2peak, 60% (p < 0.001) of the variance could be explained, with FEV1 accounting for 30% of the variance. Quadriceps total work was a significant determinant of all exercise tests. CONCLUSIONS: Cardiac function is related to exercise capacity, however is not a primary determinant. Determinants of the different constructs of exercise capacity vary, but there is a strong relationship between quadriceps force and functional and endurance exercise performance, and between lung function and peak exercise capacity.

Reliability, construct validity and determinants of 6-minute walk test performance in patients with chronic heart failure.

BACKGROUND: In-depth analyses of the measurement properties of the 6-minute walk test (6MWT) in patients with chronic heart failure (CHF) are lacking. We investigated the reliability, construct validity, and determinants of the distance covered in the 6MWT (6MWD) in CHF patients. METHODS: 337 patients were studied (median age 65years, 70% male, ejection fraction 35%). Participants performed two 6MWTs on subsequent days. Demographics, anthropometrics, clinical data, ejection fraction, maximal exercise capacity, body composition, lung function, and symptoms of anxiety and depression were also assessed. Construct validity was assessed in terms of convergent, discriminant and known-groups validity. Stepwise linear regression was used. RESULTS: 6MWT was reliable (ICC=0.90, P<0.0001). The learning effect was 31m (95%CI 27, 35m). Older age (≥65years), lower lung diffusing capacity (<80% predicted) and higher NYHA class (NYHA III) were associated with a lower likelihood of a meaningful increase in the second test (OR 0.45-0.56, P<0.05 for all). The best 6MWD had moderate-to-good correlations with peak exercise capacity (rs=0.54-0.69) and no-to-fair correlations with body composition, lung function, ejection fraction, and symptoms of anxiety and depression (rs=0.04-0.49). Patients with higher NYHA classes had lower 6MWD. 6MWD was independently associated with maximal power output during maximal exercise, estimated glomerular filtration rate and age (51.7% of the variability). CONCLUSION: 6MWT was found to be reliable and valid in patients with mild-to-moderate CHF. Maximal exercise capacity, renal function and age were significant determinants of the best 6MWD. These findings strengthen the clinical utility of the 6MWT in CHF.

Echocardiographic abnormalities and their impact on health status in patients with COPD referred for pulmonary rehabilitation.

BACKGROUND AND OBJECTIVE: Both patients with cardiac diseases as well as those with COPD report an impaired health status. The frequencies of objectively assessed co-morbid cardiac diseases and their impact on health status in patients with COPD are unknown. We aimed to investigate echocardiographic abnormalities and their impact on health status in a large cohort of patients with COPD referred for pulmonary rehabilitation (PR). METHODS: In this cross-sectional, observational analyses, demographic and clinical characteristics were assessed during an inpatient pre-PR assessment. All patients underwent Doppler echocardiographic evaluation. Health status was assessed using the COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ) and St George's Respiratory Questionnaire (SGRQ). RESULTS: A total of 514 patients (55.3% males, age: 64.1 (9.1) years, forced expiratory volume in 1 s (FEV1 ): 48.6 (20.0) % predicted) were included for analyses. Two hundred and seventy-six patients (53.7%) were diagnosed with one or more echocardiographic abnormalities. Most prevalent were left ventricular (LV) hypertrophy (LVH, 31.0%), increased right ventricular systolic pressure (RVSP, 20.4%) and impaired LV ejection fraction (LVEF, 16.5%). Of the 276 patients, 176 (63.8%) with echocardiographic abnormalities did not have these recorded in their medical history. Patients with echocardiographic abnormalities reported a worse health status as assessed with the SGRQ total score (62.5 (17.1) vs 59.3 (17.6) points, P = 0.044). CCQ and CAT did not differ between groups. CONCLUSION: More than half of the patients referred to PR had echocardiographic abnormalities of which two-third did not have them recorded in their medical history. We detected a limited impact of echocardiographic abnormalities on health status.

Predicting hospitalization and mortality in patients with heart failure: The BARDICHE-index.

BACKGROUND: Prediction of events in chronic heart failure (CHF) patients is still difficult and available scores are often complex to calculate. Therefore, we developed and validated a simple-to-use, multidimensional prognostic index for such patients. METHODS: A theoretical model was developed based on known prognostic factors of CHF that are easily obtainable: Body mass index (B), Age (A), Resting systolic blood pressure (R), Dyspnea (D), N-termInal pro brain natriuretic peptide (NT-proBNP) (I), Cockroft-Gault equation to estimate glomerular filtration rate (C), resting Heart rate (H), and Exercise performance using the 6-min walk test (E) (the BARDICHE-index). Scores were given for all components and added, the sum ranging from 1 (lowest value) to 25 points (maximal value), with estimated risk being highest in patients with highest scores. Scores were categorized into three groups: a low (≤8 points); medium (9-16 points), or high (>16 points) BARDICHE-score. The model was validated in a data set of 1811 patients from two prospective CHF-cohorts (median follow-up 887days). The primary outcome was 5-year all-cause survival. Secondary outcomes were 5-year survival without all-cause hospitalization and 5-year survival without CHF-related hospitalization. RESULTS: There were significant differences between BARDICHE-risk groups for mortality (hazard ratio=3.63 per BARDICHE-group, 95%-CI 3.10-4.25), mortality or all-cause hospitalization (HR=2.00 per BARDICHE-group, 95%-CI 1.83-2.19), and mortality or CHF-related hospitalization (HR=3.43 per BARDICHE-group, 95%-CI 3.01-3.92; all P<10-50). Outcome was predicted independently of left ventricular ejection fraction (LVEF) and gender. CONCLUSIONS: The BARDICHE-index is a simple multidimensional prognostic tool for patients with CHF, independently of LVEF.

What is the impact of impaired left ventricular ejection fraction in COPD after adjusting for confounders?

BACKGROUND: It remains unknown whether and to what extent impaired left ventricular ejection fraction (LVEF) affects physical and psychological status in COPD. We aimed to compare health outcome measures between COPD patients with and without impaired LVEF after adjusting for age, sex, BMI and FEV1. METHODS: Impaired LVEF was defined as values <50%. 85 COPD patients with impaired LVEF and 85 COPD patients with normal LVEF were matched for sex, age, BMI and FEV1. Exercise capacity, quadriceps muscle function, functional mobility, inflammatory status, health status, care dependency, and mood disorders were cross-sectionally assessed. RESULTS: Patients with impaired LVEF had shorter 6-minute walk distance (mean -59 (95% confidence interval: -94, -25)m), lower symptom-limited peak oxygen uptake (-131 (-268, 7)ml/min), weaker quadriceps muscles (-12 (-20, -3)Nm) and had more symptoms of anxiety (+2 (1, 3) points) and depression (+1 (0, 2) points) than those with normal LVEF (all P<0.05). Health status was not statistically different between groups (P>0.05). CONCLUSIONS: Impaired LVEF has a clear impact on physical and psychological status in patients with COPD, even after adjusting for confounders. This reinforces the importance of assessing and treating cardiac problems in COPD.

Heterogeneity in clinical characteristics and co-morbidities in dyspneic individuals with COPD GOLD D: findings of the DICES trial.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous respiratory disease with important extra-pulmonary features and comorbidities. The aim of this study was to assess clinical heterogeneity in a well-defined subgroup of individuals with COPD GOLD D, including possible gender differences. METHODS: Pulmonary function, arterial blood gases, exercise performance, quadriceps muscle function, problematic activities of daily life, dyspnea, health status and comorbidities have been assessed in 117 individuals with a MRC dyspnea grade 4/5 and COPD GOLD D entering pulmonary rehabilitation. RESULTS: A broad range of values were found for diffusion capacity, exercise capacity, quadriceps muscle function and health status. Indeed, the high coefficients of variation were found for these outcomes. Problematic activities of daily life as well as objectified comorbidities also varied to a great extent. Moreover, significant gender differences were found for exercise performance, lower-limb muscle function and various comorbidities. CONCLUSION: The current findings emphasize that COPD is a heterogeneous disease whose clinical presentation varies significantly, even in individuals with very severe COPD with the same degree of dyspnea and all classified as GOLD D. TRIAL REGISTRATION: NTR2322.

Prospective study on clinical effects of renal replacement therapy in treatment-resistant congestive heart failure.

BACKGROUND/AIMS: Clinical outcome in cardiorenal syndrome (CRS) Type 2 and treatment with dialysis. METHODS: Prospective observational non-randomized study. RESULTS: Twenty-three patients were included, mean age 66±21 years. Twelve (52%) patients were treated with peritoneal dialysis (PD) and 11 (48%) with intermittent haemodialysis (IHD). Median survival time after start of dialysis was 16 months. Hospitalizations for cardiovascular causes were reduced (1.4±0.6 pre-dialysis versus 0.4±0.6 days/patient/month post-dialysis, P=0.000), without significant changes in hospitalization for all causes (1.8±1.6 versus 2.1±2.9 days/patient/month). New York Heart Association (NYHA) class (3.8±0.4 at start versus 2.4±0.7 after 4 months, P=0.000, versus 2.7±0.9 after 8 months, P=0.001) and quality of life tended to improve (63±21 at start, versus 41±20 after 4 months, versus 51±25 after 8 months; P=0.056). Left ventricular ejection fraction did not change. The number of technical complications associated with dialysis therapy was relatively high in this population. CONCLUSIONS: After starting dialysis for CRS, hospitalizations for cardiovascular causes were reduced, but not hospitalizations for all causes. Functional NYHA class improved and quality of life tended to improve, without evidence for a change in cardiac function. In this small study, no differences between IHD and PD were observed.

Frequency and relevance of ischemic electrocardiographic findings in patients with chronic obstructive pulmonary disease.

Cardiovascular disease is common in patients with chronic obstructive pulmonary disease (COPD) but often remains unrecognized. Ischemic electrocardiographic (ECG) changes are associated with a higher risk of dying from coronary heart disease but have never been systematically evaluated in COPD. Also, their relation to clinical outcome has not been studied. We aimed to determine the frequency of ischemic ECG changes and its relevance in relation to clinical outcome and predictors of impaired survival in patients with COPD. Clinical characteristics, pulmonary function, and co-morbidities were assessed in 536 patients with COPD during baseline assessment of a comprehensive pulmonary rehabilitation program. Moreover, electrocardiograms at rest were obtained in all patients. All electrocardiograms were scored independently by 2 cardiologists using the Minnesota scoring system. Major or minor Q or QS pattern, ST junction and segment depression, T-wave items, or left bundle branch block were considered ischemic ECG changes. One hundred thirteen patients (21%) had ischemic ECG changes. Moreover, 42 of 293 patients (14%) without self-reported cardiovascular co-morbidities had ischemic ECG changes. In addition, patients with ischemic ECG changes had higher dyspnea grades (Modified Medical Research Council (mMRC) 2.9 ± 1.1 vs 2.6 ± 1.1, p = 0.032), worse exercise performance (6-minute walking distance 387 ± 126 vs 425 ± 126 m, p = 0.004), more systemic inflammation (high-sensitivity C-reactive protein 11.2 ± 16.2 vs 7.9 ± 10.7 mmol/l, p = 0.01), higher scores on the Charlson Co-morbidity Index (1.8 ± 0.9 vs 1.5 ± 0.8 points), and higher scores BODE (5.3 ± 3.7 vs 4.5 ± 3.4 points, p = 0.033) and on ADO indexes (5.2 ± 1.7 vs 4.8 ± 1.7 points, p = 0.029) compared to patients without ischemic ECG changes, whereas forced expiratory volume in the first second was similar (40.8 ± 15.2% vs 42.6% ± 15.9%, p = 0.30). In conclusion, ischemic ECG changes are common in patients with COPD and associated with poor clinical outcome irrespective of forced expiratory volume in the first second. These results suggest an important role for cardiovascular disease in impaired survival in these patients.

Objective physical activity assessment in patients with chronic organ failure: a validation study of a new single-unit activity monitor.

OBJECTIVE: To validate a new activity monitor (CAM) in patients with chronic organ failure during 1 hour of unconstrained activity assessment. DESIGN: A validation study in which participants wore a CAM (placed on the thigh) for 1 hour while they were videotaped. Participants were instructed to continue their normal daily routine at the rehabilitation center. SETTING: CIRO+, A Centre of Expertise for Chronic Organ Failure. PARTICIPANTS: Chronic organ failure patients (N=10) with a large range of functional exercise capacity. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Agreement in time spent on activities and postures according to video and CAM. RESULTS: Cohen kappa coefficients for transient events resulted in an almost perfect agreement (0.85 ± 0.08) between the CAM and video. CONCLUSIONS: The CAM is a promising single-sensor unobtrusive tool for providing accurate data on the type and duration of daily activities in the home environment of patients with chronic organ failure.

Task-related oxygen uptake during domestic activities of daily life in patients with COPD and healthy elderly subjects.

BACKGROUND: Patients with COPD generally have a poor peak aerobic capacity and, therefore, may experience more inconvenience during domestic activities of daily life (ADLs). Yet, task-related oxygen uptake and symptom perception during ADLs have been studied rarely in COPD. Therefore, it remains unknown whether and to what extent differences may exist in task-related oxygen uptake and symptom perception during ADLs in patients with COPD after stratification for sex; GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage; Medical Research Council (MRC) dyspnea grade; or score on the BMI, obstruction, dyspnea, exercise capacity (BODE) index. METHODS: Ninety-seven patients with COPD and 20 healthy elderly subjects performed the following five self-paced domestic ADLs with 4-min rest intervals: putting on socks, shoes, and vest; folding eight towels; putting away groceries; washing four dishes, cups, and saucers; and sweeping the floor for 4 min. Task-related oxygen uptake was assessed using an Oxycon Mobile device, whereas Borg scores were used to assess task-related dyspnea and fatigue. RESULTS: Patients with COPD used a significantly higher proportion of their peak aerobic capacity and ventilation to perform ADLs than did the healthy subjects, accompanied by higher task-related Borg dyspnea scores. Patients with GOLD stage IV, MRC dyspnea grade 5, or BODE score ≥ 6 points had the highest task-related oxygen uptake and dyspnea perception during the performance of domestic ADLs. Results showed no sex-related differences. CONCLUSION: Patients with COPD experience a relatively high metabolic load and symptom perception during the performance of ADLs that is not the same as seen in their healthy peers, particularly in patients with GOLD stage IV, MRC dyspnea grade 5, or BODE score ≥ 6 points.

Task-related oxygen uptake and symptoms during activities of daily life in CHF patients and healthy subjects.

Patients with chronic heart failure (CHF) have a significantly lower peak aerobic capacity compared to healthy subjects, and, may therefore experience more inconvenience during the performance of domestic activities of daily life (ADLs). To date, the extent to which task-related oxygen uptake, heart rate, ventilation and symptoms during the performance of ADLs in CHF patients is different than in healthy subjects remains uncertain. General demographics, pulmonary function, body composition and peak aerobic capacity were assessed in 23 CHF outpatients and 20 healthy peers. In addition, the metabolic requirement of five simple self-paced domestic ADLs was assessed using a mobile oxycon. Task-related oxygen uptake (ml/min) was similar or lower in CHF patients compared to healthy subjects. In contrast, patients with CHF performing ADLs consumed oxygen at a higher proportion of their peak aerobic capacity than healthy subjects (p < 0.05). For example, getting dressed resulted in a mean task-related oxygen uptake of 49% of peak aerobic capacity, while sweeping the floor resulted in a mean task-related oxygen uptake of 52% of peak aerobic capacity, accompanied by significantly higher Borg symptom scores for dyspnea and fatigue (p < 0.05). Patients with CHF experience use a higher proportion of their peak aerobic capacity, peak ventilation and peak heart rate during the performance of simple self-paced domestic ADL than their healthy peers. These findings represent a necessary step in improving our understanding of improving what troubles patients the most-not being able to do the things that they could when they were healthy.

Effects of neuromuscular electrical stimulation of muscles of ambulation in patients with chronic heart failure or COPD: a systematic review of the English-language literature.

INTRODUCTION: Despite optimal drug treatment, many patients with congestive heart failure (CHF) or COPD still experience disabling dyspnea, fatigue, and exercise intolerance. They also exhibit significant changes in body composition. Attempts to rehabilitate these patients are often futile because conventional exercise-training modalities are limited by the severity of exertional dyspnea. Therefore, there is substantial interest in new training modalities that do not evoke dyspnea, such as transcutaneous neuromuscular electrical stimulation (NMES). MATERIALS AND METHODS: In this article, we systematically review the literature that addresses the effects of NMES applied to the muscles of ambulation. We focused on the effects of NMES on strength, exercise capacity, and disease-specific health status in patients with CHF or COPD. We also address the methodological quality of the reported studies as well as the safety of NMES. Manuscripts published prior to December 2007 were identified by searching the Medline/PubMed, Embase, Cochrane Controlled Trials Register, CINAHL, and Physiotherapy Evidence Database (PEDro) databases. RESULTS: Fourteen trials were identified (nine trials that examined NMES in CHF patients, and five in COPD patients). PEDro scores for methodological quality of the trials were generally moderate to good. Many of the studies reported significant improvements in muscle strength, exercise capacity, and/or health status. DISCUSSION: Nonetheless, the limited number of studies, the disparity in patient populations, and the variability in NMES methodology prohibit the use of metaanalysis. Yet, from the viewpoint of a systematic review, NMES looks promising as a means of rehabilitating patients with CHF and COPD. There is at least sufficient evidence to warrant more large prospective, randomized, controlled trials.

Measuring body composition in chronic heart failure: a comparison of methods.

AIMS: Fat-free mass (FFM) is increasingly recognized as a systemic marker of disease severity in chronic organ failure and is an important target for physiologic and pharmacologic interventions to improve functional status. The aim of this study was therefore to evaluate two clinical methods to assess FFM in patients with chronic heart failure (CHF) using deuterium dilution (DEU) as reference and bromide dilution to assess the ratio between intracellular (ICW) and extracellular water (ECW) as potential confounder. METHODS: Body composition was measured with dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA) and DEU in 22 stable patients from our heart failure outpatient clinic and 24 healthy age matched controls. RESULTS: FFM values measured by DXA and DEU in patients (r = 0.92, SEE: 3.1 kg) and controls (r = 0.99, SEE: 1.3 kg) were strongly related. In both patients and controls, the inter method difference increased with higher values of FFM (DXA overestimating DEU). The ICW/ECW ratio was within the normal range and comparable between the groups. In patients, a highly significant correlation coefficient was found (r = 0.93, SEE 2.1 p = 0.01) between total body water (DEU) and height squared/resistance (Ht2/R). On multiple regression next to Ht2/R, body weight was an independent predictor of FFM(DEU) (r = 0.95, SEE 2.5 kg, p<0.001; TBWdeu = 0.528 Ht2/R + (0.182 weight) + 8.277). CONCLUSION: DXA and DEU are appropriate and interchangeable laboratory methods for assessment of FFM in clinically stable heart failure patients, however, overestimation of FFM(DXA) should be considered. BIA is a suitable clinical alternative for diagnostic purposes.