Melissa Jehn

An official European Respiratory Society statement on physical activity in COPD

This European Respiratory Society (ERS) statement provides a comprehensive overview on physical activity in patients with chronic obstructive pulmonary disease (COPD). A multidisciplinary Task Force of experts representing the ERS Scientific Group 01.02 “Rehabilitation and Chronic Care” determined the overall scope of this statement through consensus. Focused literature reviews were conducted in key topic areas and the final content of this Statement was agreed upon by all members. The current knowledge regarding physical activity in COPD is presented, including the definition of physical activity, the consequences of physical inactivity on lung function decline and COPD incidence, physical activity assessment, prevalence of physical inactivity in COPD, clinical correlates of physical activity, effects of physical inactivity on hospitalisations and mortality, and treatment strategies to improve physical activity in patients with COPD. This Task Force identified multiple major areas of research that need to be addressed further in the coming years. These include, but are not limited to, the disease-modifying potential of increased physical activity, and to further understand how improvements in exercise capacity, dyspnoea and self-efficacy following interventions may translate into increased physical activity. The Task Force recommends that this ERS statement should be reviewed periodically (e.g. every 5–8 years). An official ERS statement providing a comprehensive overview on physical activity in patients with COPD http://ow.ly/C6v78

Accelerometer-based quantification of 6-minute walk test performance in patients with chronic heart failure : applicability in telemedicine

BACKGROUND Distance walked in the 6-minute walk test (6MWT) is an important prognostic parameter used clinically to assess functional status in patients with chronic heart failure (CHF). In this study, we investigated if alternative performance parameters with similar prognostic value can be gained from accelerometers. METHODS AND RESULTS Fifty CHF patients (age, 60.9 +/- 14.0 years) were asked to perform a 6MWT while wearing 2 accelerometers and 1 pedometer. Total 6MWT step frequency (SF) and activity counts (VMU) were correlated to 6MWT distance. The accelerometer was highly accurate at quantifying SF (detected vs. observed: r = 0.99; P < .001), whereas the pedometer was unreliable below 50 m/min. VMU increased linearly with walking speed (r = 0.99), and both SF and VMU correlated strongly with 6MWT distance (VMU: r = 0.91; SF: r = 0.87, respectively; P < .001) and each other (r = 0.80, P < .001). CONCLUSIONS Accelerometers are reliable in measuring physical performance during the 6MWT in CHF patients. Besides the simple acquisition of 6MWT distance currently used for patient assessment, accelerometers provide new data that might be useful to evaluate exercise performance during the 6MWT. This allows for routine assessment of exercise capacity in a home-based setting in the context of telemedicine.

Daily walking performance as an independent predictor of advanced heart failure : Prediction of exercise capacity in chronic heart failure

PURPOSE The purpose of this study was to use an accelerometer to measure daily walking performance in patients with chronic heart failure (CHF) to investigate if this parameter is a determinant of New York Heart Association class and indicative of maximal and functional exercise capacity. METHODS Fifty patients with CHF were instructed to wear an accelerometer for 7 consecutive days while going about their daily business. Maximal and functional exercise capacity was assessed by cardiopulmonary (VO(2peak)) and 6-minute walk testing, respectively. RESULTS Patients in New York Heart Association I, II, and III reached an average total walking time (TWT) of 160.6 +/- 35.8 minutes, 133.9 +/- 59.0 minutes, and 76.1 +/- 22.5 minutes per day of which 19%, 19%, and 9% where spent in the fast walking mode (>83 m/minute), respectively. The TWT correlated strongly with VO(2peak) (r = 0.72; P <.001) and 6-minute walk testing distance (r = 0.68; P <.001). The TWT and time spent in fast walking mode were the strongest determinants in discriminating moderate CHF. CONCLUSION Daily walking performance is a clear determinant of maximal and functional exercise capacities in patients with CHF. Walking intensity in particular is an independent predictor in discriminating patients with advanced heart failure. Monitoring of daily walking performance might aid in detecting disease progression and improve clinical outcome.

Association of daily physical activity volume and intensity with COPD severity

PURPOSE The purpose of this study was to assess whether daily walking activity is indicative of disease severity in patients with COPD. METHODS Daily activity was measured by accelerometry in 107 COPD: GOLD II (N=28), GOLD III (N=51), and GOLD IV (N=25). Steps per day and times (min/day) spent passively, actively, walking (WLK, 0-5 km/h), and fast walking (FWLK, >5 km/h) were analyzed. Total walking time (TWT) was computed. RESULTS Times spent WLK (P=0.031), FWLK (P=0.001), TWT (P=0.021), and steps per day (P=0.013) differed significantly between GOLD stages. There was a significant negative correlation between TWK and GOLD stage (R=-0.35; P<0.0001), BODE index (R=-0.58; P<0.0001), and MMRC dyspnea scale (R=-0.65; P<0.0001). Logistic regression analysis showed that both TWT and FWLK were independently and significantly associated with BODE index ≥ 6 (P=0.029 and P=0.040, respectively). The corresponding AUC-value with 95% CI for TWT was 0.80 (95% CI: 0.70 to 0.90) and 0.87 (95% CI: 0.81 to 0.94) for FWLK. The corresponding optimal cut-off value for TWT was 33.3 min/day (sensitivity: 86%; specificity 70%) and FWLK was 0.10 min/day (sensitivity: 93%; specificity 76%). CONCLUSION Daily walking activity, in particular walking intensity, is significant predictor of disease severity in patients with COPD. Objective measures of habitual activity might provide additive value in assessing the likelihood of poor prognosis in this patient cohort.

Pedometer accuracy in patients with chronic heart failure.

This study assesses the accuracy of the Omron HJ-720ITC pedometer at low walking intensities in patients with chronic heart failure. Step accuracy was assessed by visual observation on the treadmill and during free walking at 40, 50, 60, 70, 80 m/min, as well as during self paced walking using the 6 min walk test. A total of ninety-seven patients with heart failure (mean age: 61+/-13, NYHA I, N=30; NYHA II, N=32; NYHA III, N=35) participated in the study. At predefined walking speeds, a statistically significant % error in pedometer accuracy was evident at 60 m/min (p=0.039), and% error increased markedly below this threshold. Highest% error in pedometer accuracy was seen at 40 m/min (mean bias (% error): 28.3+/-9.0%; 95% CI: 21.8-34.7; p<0.001). During self paced walking (6MWT) the absolute% error in pedometer readings was largest in patients with strongest functional limitations and 6 MWT distances <400 m (mean bias (% error): 10.7+/-13.6%; CI 5.6-15.4, p<0.001). The Omron HJ-720ITC pedometer is accurate for monitoring activity in individuals with normal walking behaviour, but seems unsuitable for chronically ill patients characterised by slow walking gaits.

Multivariable analysis of heart rate recovery after cycle ergometry in heart failure: Exercise in heart failure

PURPOSE The purpose of this study was to investigate the association between impairment in heart rate recovery (HR(rec)) after cycle ergometry and prognostic markers in patients with heart failure (HF) compared with healthy controls. METHODS Fifty patients with chronic HF (systolic HF, N = 30; diastolic HF, N = 20; mean age = 62 ± 12 years) and 50 healthy controls (N = 50; mean age = 66 ± 13 years) underwent 2-dimensional and M-mode echocardiography followed by cardiopulmonary exercise testing. Independent predictors of HR(rec) at 1 and 2 minutes after exercise were analyzed by univariable and multivariable regression analyses, and receiver operating characteristics were performed to obtain area under the curve. RESULTS In HF, left ventricular end-diastolic diameter (millimeters), left ventricular ejection fraction (%), N-terminal pro-brain natriuretic peptide (picograms/milliliter), peak oxygen uptake (VO(2)peak [milliliters/kilogram/min]), and peak heart rate (HR(peak)) showed a significant association with HR(rec) (beats/min) in univariate regression analyses (P < .001), but only VO(2)peak remained independently predictive of both HR(rec)1 (P = .034) and HR(rec)2 (P = .008) in the multivariable regression analyses. In controls, VO(2)peak (P = .035) and HR(peak) (P = .032) were significantly associated with HR(rec)2 in univariate analyses only. Optimal cutoff values for discriminating HF versus non-HF based on HR(rec) were 17.5 beats/min (sensitivity 92%; specificity 74%) for HR(rec)1 and 31.5 beats/min (sensitivity 94%; specificity 86%) for HR(rec)2. Optimal cutoff values for discriminating systolic HF versus diastolic HF were 12.5 beats/min (sensitivity 78%; specificity 80%) for HR(rec)1 and 24.5 beats/min (sensitivity 82%; specificity 90%) for HR(rec)2. CONCLUSION Impairment in after exercise HR(rec) is significantly and independently associated with VO2peak in HF and thus might constitute a useful tool for assessing the degree of functional status during exercise rehabilitation.

Associations of daily walking activity with biomarkers related to cardiac distress in patients with chronic obstructive pulmonary disease

Background: The prevalence of cardiovascular mortality is high in Chronic Obstructive Pulmonary Disease (COPD) and the identification of clinical parameters to improve risk stratification is of great interest. Objectives: This study aims to assess the predictive strength of daily walking activity on expression of cardiac biomarkers in patients with COPD. Methods: One hundred and five patients with COPD (66.1 ± 8.7 years of age) were prospectively analyzed. Daily walking activity was measured by means of accelerometry. Stepwise multivariate regression analyses were employed with either midregional proatrial natriuretic peptide (MRproANP) or plasma proadrenomedullin (MRproADM) as dependent variables, and age, age-adjusted Charlson score, Modified Medical Research Council Dyspnea Scale (MMRC), Saint Georges Respiratory Questionnaire total score and either total walk, steps per day or fast walk as covariates. Results: Independent predictors of MRproANP included age (p = 0.015) and either total walk or steps per day (both p < 0.0001). Total walk or steps per day were the only independent predictors of MRproADM (p < 0.0001). There was a significant negative correlation between fast walk and MMRC (R = -0.70; p < 0.001) and fast walk was only independently predictive of MRproANP but not MRproADM once MMRC was excluded from the list of covariates (p = 0.023 and p = 0.057, respectively). Conclusions: Daily walking activity independently predicts levels of circulating MRproANP and MRproADM in stable COPD patients, two prognostic biomarkers of cardiac distress associated with long-term survival upon exacerbation of COPD. Employing activity monitors in the stable state might simplify risk stratification in daily living.

The Effects of Climate Change on Patients With Chronic Lung Disease. A Systematic Literature Review.

BACKGROUND Ever since higher overall mortality rates due to heat stress were reported during the European heat waves of 2003 and 2006, the relation between heat waves and disease-specific events has been an object of scientific study. The effects of heat waves on the morbidity and mortality of persons with chronic lung disease remain unclear. METHODS We conducted a systematic search using PubMed, the Cochrane Library, and Google Advanced Search to identify relevant studies published between 1990 and 2015. The reference lists of the primarily included articles were searched for further pertinent articles. All articles were selected according to the PRISMA guidelines. The heat-wave-related relative excess mortality was descriptively expressed as a mean daily rate ratio ([incidence 1]/[incidence 2]), and the cumulative excess risk (CER) was expressed in percent. RESULTS 33 studies with evaluable raw data concerning the effect of heat waves on patients with chronic lung disease (chronic obstructive pulmonary disease, bronchial asthma, pulmonary arterial hypertension, and idiopathic pulmonary fibrosis) were analyzed in this review. By deriving statistics from the overall data set, we arrived at the conclusion that future heat waves will-with at least 90% probability-result in a mean daily excess mortality (expressed as a rate ratio) of at least 1.018, and-with 50% probability-in a mean daily excess mortality of at least 1.028. These figures correspond, respectively, to 1.8% and 2.8% rises in the daily risk of death. CONCLUSION Heat waves significantly increase morbidity and mortality in patients with chronic lung disease. The argument that the excess mortality during heat waves is compensated for by a decrease in mortality in the subsequent weeks/months (mortality displacement) should not be used as an excuse for delay in implementing adaptive strategies to protect lung patients from this risk to their health.

Novel water born cooling system enables early mobilization of patients hospitalized for urban heat stress related chronic lung disease progression

Introduction: The aim of this study was to investigate whether climate controlled patient rooms support earlier mobilization of patients admitted for exacerbation of chronic lung disease. Methods: This randomized clinical trial conducted summer 2014, branched into conventional patient rooms without climatization G2 (T mean 24.9°C, max. T 30.5 °C) versus patient rooms equipped with capillary tube mats G1 (set point temperature 23 °C (Clina Cooling Inc.)). 32 patients (mean age 67 years, COPD 76 %, 12 % PAH and 12 % Asthma) were eligible for data analyses. In order to acquire mobility data a validated activity tracker (Withings pulse, Aipermon 440) was attached to the patients and movements were continuously detected during stay in hospital. The results from activity tracking were correlated to patient continuous sheets documented 6- Minutes- Walking- Test (6-MWT). Results: Patients enrolled in the radiant climate controlled rooms group G1 had a 20.3 % higher mean daily move count - 884 (CI 95%, 453- 1314, p<0.05) versus patients in control rooms G2 - 734 (CI 95%, 340 – 1128, p<0.05). The same applied to 6-MWT, where G1 came up with 16.9% higher mean values (G1: 186.9 m, 95% CI 76-623, p<0.05 versus G2: 159.2 m, 95% CI 143.4- 230.4, p<0.05 ). Moreover, since patients in the climate controlled rooms stayed compared to control group mean 3,07 days less in hospital the maximum activity rate on discharge was obtained earlier and at a higher positive slope in G1. Conclusion: Hospital room equipped with innovative water born cooling system supports earlier mobilization in heat stress impaired patients suffering from chronic lung disease.

Response to letter to the editor by Dr. Vitor Oliveira Carvalho and Guilherme Veiga Guimaraes: Is the 6-min walking test a submaximal exercise test in heart failure patients?

We thank Carvalho and Guimaraes (2009) for their interest in our article (Jehn et al. 2009). The primary purpose of our study was to measure the cardio-respiratory response during a constant load exercise test (6-min walk test) in patients with heart failure and compare peak values with an incremental exercise test (ramp protocol). We agree with Carvalho et al. that a treadmill test would have been a more direct comparison to the 6-min walk test regarding exercise mode. However, treadmill tests are rarely done in patients with heart disease in many European countries, in particular Germany. Thus, we wanted our test outcome to be as closely related to its clinical applicability as possible. In support of our data, it has been previously shown that the cardio-respiratory response and its prognostic utility are not greatly impacted by the mode of exercise in patients with heart failure, and that test outcome of the CPET can be applied globally, irrespective of exercise modality (i.e. treadmill vs. cycle ergometry) (Arena et al. 2005). The importance in eliciting a maximal exercise response lies predominately in the nature of the preferred exercise test, in other words, what the patient feels more comfortable with (Albouaini et al. 2007; Piepoli et al. 2006). This goes for walking versus cycling as well as constant load versus incremental exercise stress test (CPET). The main reason why cycle ergometry often is avoided as means of CPET testing in many western countries is usually due to the general inability of individuals in riding a bike, albeit it offers more stability and technically better ECG data which is of particular pertinence in cardiac patients during exercise testing. Within our study population, however, the use of a bicycle acts as a widespread mode of transportation within the general community and most patients felt more comfortable on a cycle ergometer than the treadmill. Carvalho et al. raise an important aspect by pointing out that the use of prognostic cut-off values for VO2 peak (14 ml/kg per min) provided in the literature (Frankenstein et al. 2007; Parikh et al. 2009) would have added to the clinical importance of our findings. However, considering our small study population size, we wanted to ensure that the groups were as closely matched in size (N) as possible. Likewise, we do agree that both the use of the Borg scale and the respiratory exchange ratio (RER) are important aspects of ensuring an adequate maximal exercise response during exercise testing, as they offer both subjective and objective measures of exertion, respectively (Carvalho et al. 2009). Both, the Borg scale (C18) and RER C 1.05, were used as measures of maximal performance in our study, and patients not meeting these criteria were excluded from the analyses. Our main prerogative was to show that the value in eliciting a maximal exercise response in patients with heart failure lies predominately in choosing the appropriate exercise test and is dependent on the functional status and exercise limitations of that particular patient. Moreover, our findings indicate a constant load exercise test (in which individuals choose their own workload and thus exercise intensity) to elicit higher peak respiratory parameters than incremental stress testing in patients with limited exercise capacity. Communicated by Susan Ward.