Heart rate recovery after the 6 min walk test rather than distance ambulated is a powerful prognostic indicator in heart failure with reduced and preserved ejection fraction: a comparison with cardiopulmonary exercise testing. Relation of Longitudinal Changes in Quality of Life Assessments to Changes in Functional Capacity in Patients With Heart Failure With and Without Anemia. Repeat six-minute walk tests in patients with chronic heart failure: are they clinically necessary? Six-Minute Walk Test and Cardiopulmonary Exercise Testing in Patients With Chronic Heart Failure: A Comparative Analysis on Clinical and Prognostic Insights Single‐dose intravenous iron in Southeast Asian heart failure patients: A pilot randomized placebo‐controlled study (PRACTICE‐ASIA‐HF) Effect of the long-term administration of nebivolol on clinical symptoms, exercise capacity and left ventricular function in patients with heart failure and preserved left ventricular ejection fraction: background, aims and design of the ELANDD study Submaximal exercise testing in the assessment of interstitial lung disease secondary to systemic sclerosis: reproducibility and correlations of the 6-min walk test The influence of alternative instruction on 6-min walk test distance. Effects of continuous positive airway pressure on pulmonary function and exercise tolerance in patients with congestive heart failure. Physiologic responses to incremental and self-paced exercise in COPD: a comparison of three tests. Diastolic function is associated with quality of life and exercise capacity in stable heart failure patients with reduced ejection fraction A group-based exercise program did not improve physical activity in patients with chronic heart failure and comorbidity: a randomized controlled trial. [Reference Equations for the 6-Minute Walk Test in Healthy Individuals.] A randomised, controlled study of rate versus rhythm control in patients with chronic atrial fibrillation and heart failure: (CAFÉ-II Study) Reliability, validity, and responsiveness of the six-minute walk test in patients with heart failure. Shuttle Walking Test and 6-Minute Walking Test Induce a Similar Cardiorespiratory Performance in Patients Recovering from an Acute Exacerbation of Chronic Obstructive Pulmonary Disease Aquatic Exercise Training is Effective in Maintaining Exercise Performance in Trained Heart Failure Patients: A Randomised Crossover Pilot Trial. The Effect of Biofeedback on Function in Patients with Heart Failure Effects of aerobic exercise training on variability and heart rate kinetic during submaximal exercise after gastric bypass surgery – a randomized controlled trial Six-minute walking versus shuttle walking: responsiveness to bronchodilation in chronic obstructive pulmonary disease Beneficial effects of long-term intravenous iron therapy with ferric carboxymaltose in patients with symptomatic heart failure and iron deficiency† Lack of Specificity of the 6-Minute Walk Test as an Outcome Measure for Patients with Systemic Sclerosis Cardiac rehabilitation in chronic heart failure: effect of an 8-week, high-intensity interval training versus continuous training.
AIMS Heart rate recovery ( HRR ) appears to be a robust prognostic marker in heart failure ( HF ) . When using the 6 min walk test ( 6MWT ) in HF , distance ambulated is generally the reference prognostic variable . We hypothesized that HRR after the 6MWT would be a better prognostic measure than distance ambulated . METHODS AND RESULTS A 6MWT and cardiopulmonary exercise testing ( CPX ) were r and omly performed in 258 HF patients [ 216 HF with reduced EF ( HFrEF ) and 42 HF preserved EF ( HFpEF ) ] , after which HRR was measured . HRR was defined as the difference between heart rate at peak exercise and 1 min following test termination . Patients were assessed for major cardiac events during a mean follow-up period of 22.8 ± 22.1 months . There were 50 major cardiac events during the tracking period . Univariate Cox regression analysis results identified HRR after both the 6MWT and CPX as a significant ( P < 0.001 ) predictor of adverse events . Multivariate Cox regression analysis revealed that dichotomized HRR after the 6MWT and CPX was the strongest predictor of survival ( χ(2 ) 61.1 and 53.8 , respectively ; P < 0.001 ) , with LVEF ( residual χ(2 ) 6.1 , P < 0.05 ) adding significant prognostic value to the 6MWT model and ventilatory efficiency ( the VE/VCO2 slope ) ( residual χ(2 ) 6.6 , P < 0 .05 ) adding significant prognostic value to the CPX model . CONCLUSIONS HRR after the 6MWT is a powerful prognosticator that performs similarly to HRR after maximal exercise . If confirmed in subsequent studies , 6MWT HRR should replace 6MWT distance as the reference criterion 6MWT measure to consider when grading cardiovascular risk in HF patients Clinical status in heart failure is conventionally assessed by the physician 's evaluation , patients ' own perception of their symptoms , quality of life ( QoL ) tools , and a measure of functional capacity . These aspects can be measured with tools such as the New York Heart Association functional class , QoL tools such as the EuropeanQoL-5 dimension , the Kansas City Cardiomyopathy Question naire , patient global assessment ( PGA ) , and by 6-minute walk test ( 6MWT ) , respectively . The ferric carboxymaltose in patients with heart failure and iron deficiency ( FAIR-HF ) trial demonstrated that treatment with intravenous ferric carboxymaltose in iron-deficient patients with symptomatic heart failure with reduced left ventricular function , significantly improved all 5 outcome measures . This analysis assessed the correlations between the longitudinal changes in the measures of clinical status , as measured by QoL tools and the changes in the measures of functional capacity as measured by the 6MWT . This analysis used the data base from the FAIR-HF trial , which r and omized 459 patients with chronic heart failure ( reduced left ventricular ejection fraction ) and iron deficiency , with or without anemia to ferrous carboxymaltose or placebo .  The degree of correlation between QoL tools and the 6MWT was assessed at 4 , 12 , and 24 weeks . The data demonstrate highly significant correlations between QoL and functional capacity , as measured by the 6MWT , at all time points ( p < 0.001 ) . Changes in PGA , Kansas City Cardiomyopathy Question naire , and EuroQoL-5D correlated increasingly over time with changes in 6MWT performance . Interestingly , the strongest correlation at 24 weeks is for the PGA , which is a simple numerical scale ( r = -0.57 , p < 0.001 ) . This analysis provides evidence that QoL assessment show a significant correlation with functional capacity , as measured by the 6MWT . The strength of these correlations increased over time Background : Owing to a reported learning effect in patients with chronic cardiopulmonary disease , performance of at least two six-minute walk tests ( 6MWT ) are recommended as st and ard practice . Patients with chronic heart failure ( CHF ) are typically elderly and frail and it is unknown whether current guidelines are practical in a clinical setting . Aims : The aim of this study was to determine whether repeat performance of 6MWTs in patients with CHF is related to between-test interval or baseline performance . Methods : This was a multisite observational study enrolling participants entering into heart failure rehabilitation programmes . Participants performed two 6MWTs with r and omly allocated inter-test intervals between 15 and 90 minutes . Distance walked in the second test was compared with the first test using a paired t test . Results : Eighty-eight participants ( 45 females , age 65 ± 14 years ) with stable CHF were enrolled . Mean distance walked increased from 301 metres in test 1 to 313 metres in test 2 ( p < 0.001 ) . No significant change was recorded between test 1 and test 2 for those whose baseline distance was < 300 metres . The interval between tests had no significant effect on the distance walked . Conclusion : The change in 6MWT distance was significantly associated with better baseline performance but not with the interval between tests Background —The six-minute walk test ( 6MWT ) and cardiopulmonary exercise testing ( CPET ) are the 2 testing modalities most broadly used for assessing functional limitation in patients with heart failure ( HF ) . A comprehensive comparison on clinical and prognostic validity of the 2 techniques has not been performed and is the aim of the present investigation . Methods and Results —Two hundred fifty-three patients diagnosed with systolic ( n=211 ) or diastolic ( n=42 ) HF ( age : 61.9±10.1 years ; New York Heart Association Class : 2.2±0.78 ) underwent a 6MWT and a symptom-limited CPET evaluation and were prospect ively followed up . During the 4-year tracking period , there were 43 cardiac-related deaths with an annual cardiac mortality rate of 8.7 % . The 6MWT distance correlated with CPET-derived variables ( ie , peak Vo2 , Vo2 at anaerobic threshold , and Ve/Vco2 slope ) and was significantly reduced in proportion with lower peak Vo2 and higher Ve/Vco2 slope classes and presence of an exercise oscillatory breathing ( EOB ) pattern ( P<0.01 ) . However , no significant differences were observed in distance covered between survivors and nonsurvivors ( 353.2±95.8 m versus 338.5±76.4 m ; P = NS ) . At univariate and multivariate Cox proportional analyses , the association of the 6MWT distance with survival was not significant either as a continuous or dicotomized variable ( ≤300 m ) . Conversely , CPET-derived variables emerged as prognostic with the strongest association found for EOB ( systolic HF ) and Ve/Vco2 slope ( entire population with HF and patients with a 6MWT≤300 m ) . Conclusions —The 6MWT is confirmed to be a simple and reliable first-line test for quantification of exercise intolerance in patients with HF . However , there is no supportive evidence for its use as a prognostic marker in alternative to or in conjunction with CPET-derived variables Abstract Aims Iron deficiency is highly prevalent in Southeast Asians with heart failure ( HF ) and associated with worse outcomes . This trial aim ed to assess the effect of intravenous iron in Southeast Asians hospitalized with decompensated HF . Methods and results Fifty patients hospitalized for acute decompensated HF , regardless of ejection fraction , with iron deficiency ( defined as serum ferritin < 300 ng/mL if transferrin saturation is < 20 % ) were r and omized to receive either one dose of intravenous ferric carboxymaltose ( FCM ) 1000 mg or placebo ( 0.9 % saline ) following HF stabilization and before discharge in two Singapore tertiary centres . The primary endpoint was difference in 6‐min walk test ( 6MWT ) distance over 12 weeks , while secondary endpoints were quality of life assessed using vali date d Kansas City Cardiomyopathy Question naire ( KCCQ ) and Visual Analogue Scale ( VAS ) . Improvement in 6MWT distance at Week 12 was observed in both FCM and placebo groups ( from 252 ± 123 to 334 ± 128 m and from 243 ± 67 to 301 ± 83 m , respectively ) . Unadjusted analysis showed 6MWT distance for FCM exceeded that for placebo , but adjustment for baseline covariates and time attenuated this effect { adjusted mean difference between groups : 0.88 m [ 95 % confidence interval ( CI ) −30.2 to 32.0 , P = 0.956]}. KCCQ overall summary and VAS were similar in both groups [ adjusted mean difference : KCCQ −1.48 ( 95 % CI −8.27 to 5.31 , P = 0.670 ) and VAS 0.26 ( 95 % CI −0.33 to 0.86 , P =  0.386  ) ] . FCM  was well tolerated with no serious treatment‐related adverse events . Conclusions Intravenous FCM administered pre‐discharge in Southeast Asians hospitalized with decompensated HF is clinical ly feasible . Changes in 6MWT distance should be measured beyond Week 12 to account for background therapy effects Background The SENIORS trial demonstrated that nebivolol has beneficial effects in patients with heart failure . However , the role of beta-blocker therapy in patients with heart failure and preserved left ventricular ejection fraction ( HFPEF ) is still unsettled . Objective To assess the long-term effects of administration of nebivolol , compared to placebo , on the clinical symptoms , exercise capacity and parameters of left ventricular ( LV ) function in patients with HFPEF . Methods The Effect of Long-term Administration of Nebivolol on clinical symptoms , exercise capacity and left ventricular function in patients with Diastolic Dysfunction ( EL AND D ) study is a prospect i ve multicenter European trial in 120 patients with HFPEF r and omised to nebivolol or placebo .  HFPEF is defined as symptoms or signs of heart failure , a LV ejection fraction > 45 % and evidence of diastolic LV dysfunction by Doppler echocardiography . Procedures include a baseline clinical examination , 6-min walk test ( 6MWT ) , electrocardiography , Doppler echocardiography and Minnesota QoL question naire . Nebivolol or placebo is started at 2.5 mg/day and gradually uptitrated to 10 mg/day . After initiation of the study , patients are assessed at 1 , 2 , 5 and 6 weeks ( titration phase ) and at weeks 12 and 26 . The primary endpoint is the change from baseline in the 6MWT distance with nebivolol versus placebo . Sample size calculations are based on an anticipated 15 % difference ( 70 m ) in the 6MWT distance between nebivolol and placebo-treated patients . This study will allow the collection of data regarding the possible clinical benefits and the effects on LV function of nebivolol administration in patients with HFPEF Background : The 6-min walk test ( 6MWT ) is increasingly used as an outcome measure in interstitial lung disease ( ILD ) . Aim : To evaluate the usefulness of the 6MWT in a cohort of patients with ILD secondary to systemic sclerosis ( SSc ) and to correlate with established physiological parameters . Methods : 163 patients with SSc-ILD were recruited for a multicentre , r and omised , double-blind clinical trial . Available data at protocol screening included repeated 6MWTs , pulmonary function testing with diffusing capacity , Doppler echocardiography and high-resolution computed tomography of the thorax . Borg Dyspnoea Index was evaluated before and after 6MWT . Results : Mean ( st and ard deviation ( SD ) ) distance walked during walk test 1 was 396.6 ( 84.55 ) m compared with 399.5 ( 86.28 ) m at walk test 2 . The within-subject , intertest correlation as determined by Pearson ’s correlation coefficient testing was 0.95 ( p<0.001 ) . However , only weak correlations of 6MWT with percentage forced vital capacity and the Borg Dyspnoea Index were observed , and no correlation was observed with percentage diffusing capacity . Conclusion : These data confirm the high reproducibility of the  6MWT in patients with SSc-ILD and therefore the validity of the test in this cohort . The lack of correlation of 6MWT with st and ard physiological parameters of ILD suggests a multifactorial basis for limited exercise capacity in patients with SSc and calls into question the utility of the 6MWT as a measure of outcome in future studies on SSc-ILD BACKGROUND The goal of the 6-min walk test ( 6MWT ) is to enable patients to walk " as far as possible " as a measure of their functional ability . The impact of the specific walk instructions on patient 6MWT performance is unknown . METHODS Patients with pulmonary arterial hypertension ( PAH ) , idiopathic pulmonary fibrosis ( IPF ) , and other forms of interstitial lung disease ( ILD ) were recruited to perform four identical 6MWTs with one differing instructional phrase . The st and ard instruction to walk " as far as possible " was substituted in r and om order with " as fast as possible , " " at your normal pace , " or " at a leisurely pace . " RESULTS Twenty-four patients ( 10 with PAH , eight with IPF , six with other ILD ) were enrolled and completed all four 6MWTs . Patients attained the greatest distance with the fast instruction , exceeding the st and ard instruction distance by a mean of 52.7 m ( P < .001 ) . The mean difference between the fast and st and ard walks was 41.5 m in the PAH group , 66.5 m in the IPF group , and 53 m in the other ILD group . CONCLUSIONS Patients do not walk as far as they are able with the st and ard American Thoracic Society instruction for 6MWT . Changing the wording from " far " to " fast " may facilitate a better effort and greater distance during the test . It is possible that this modified 6MWT instruction may result in improved accuracy and reproducibility , thereby enhancing its clinical and research trial usefulness STUDY OBJECTIVES Continuous positive airway pressure ( CPAP ) has been used to improve cardiopulmonary function and reduce pulmonary edema symptoms in patients with congestive heart failure ( CHF ) . The objective of this study was to evaluate the efficacy of CPAP therapy on pulmonary function and exercise tolerance in patients with CHF . DESIGN Prospect i ve blind r and omized clinical study . PARTICIPANTS Twenty-four patients with class II or III CHF and dilated cardiomyopathy were r and omly assigned to 30 min of CPAP therapy and respiratory exercises ( CPAP group ) or respiratory exercise only ( control group ) once a day for 14 days . MEASUREMENTS AND RESULTS Evaluation of pulmonary function was performed measuring FEV1 and FVC . Exercise tolerance was assessed measuring the distance walked during the 6-min walking test ( 6MWT ) . These parameters were measured before treatment and 4 days , 9 days , and 14 days later . CPAP therapy caused a progressive increase ( p < 0.05 ) in both FVC ( maximum of 16 % after 9 days ) and FEV1 ( maximum of 14 % after 14 days ) compared to basal values , without significant changes in the control group . The 6MWT showed a progressive improvement in the distance walked in the CPAP group , reaching approximately 28 % above the basal values in the CPAP group and without significant changes in the control group . CONCLUSIONS These data show that the use of CPAP therapy for 2 weeks on a daily basis is able to enhance pulmonary function and consequently improve the tolerance to physical activities in patients with CHF . The clinical implication of this finding is that CPAP therapy could potentially be used as an adjunct to the treatment of CHF patients OBJECTIVES To investigate cardiorespiratory and dyspnea responses to incremental and self-paced exercise tests in patients with COPD . DESIGN A prospect i ve within-subject design was used . PATIENTS Twenty stable subjects ( 15 men ) , with a mean ( + /- SD ) age of 64.0 + /- 7.5 years and moderate-to-severe COPD ( ie , mean FEV(1 ) , 0.8 + /- 0.3 L and 28.9 + /- 7.9 % predicted ) were studied . METHODS Each subject completed a 6-min walk test ( 6MWT ) , an incremental shuttle walking test ( ISWT ) , and a cycle ergometer test ( CET ) , within a 2-week period . The tests were performed at least 24 h apart . St and ardized encouragement was utilized in each test with the aim of maximizing performance . Heart rate ( HR ) and dyspnea were measured each minute throughout the tests , and pulse oximetric saturation ( Spo(2 ) ) was measured before and immediately after each test . The distances walked in the 6MWT and ISWT were compared to peak oxygen uptake ( Vo(2 ) ) values from the CET . RESULTS HR increased linearly with increasing workload during the CET and ISWT , but increased alinearly with a disproportionate increase early in the 6MWT . In contrast , dyspnea scores increased linearly during the 6MWT , but increased alinearly with a disproportionate increase late during the CET and ISWT . Peak HR and dyspnea were not significantly different between tests . Spo(2 ) was significantly lower at the end of both walking tests compared to that at the end of the CET ( p < 0.001 ) . The distance walked in both the ISWT and 6MWT were related to peak Vo(2 ) values on the CET ( for both tests , r = 0.73 ; p < 0.001 ) . CONCLUSIONS The patterns of response in HR and dyspnea seen during the 6MWT suggest that patients with COPD titrate exertion against dyspnea to achieve a peak tolerable intensity . This strategy is not possible in an externally paced ISWT or CET . However , it is a limited strategy , with performance converging at higher workloads . Similar peak exercise responses were achieved in the 6MWT , ISWT , and CET . Greater oxygen desaturation was observed during the field walking tests , suggesting that both the ISWT and 6MWT are more sensitive than the CET in detecting exercise-induced hypoxemia and in assessing ambulatory oxygen therapy needs Exercise capacity and quality of life ( QOL ) are important outcome predictors in patients with systolic heart failure ( HF ) , independent of left ventricular ( LV ) ejection fraction ( LVEF ) . LV diastolic function has been shown to be a better predictor of aerobic exercise capacity in patients with systolic dysfunction and a New York Heart Association ( NYHA ) classification ≥II . We hypothesized that the currently used index of diastolic function E/e ' is associated with exercise capacity and QOL , even in optimally treated HF patients with reduced LVEF . This prospect i ve study included 44 consecutive patients aged 55±11 years ( 27 men and 17 women ) , with LVEF<0.50 and NYHA functional class I-III , receiving optimal pharmacological treatment and in a stable clinical condition , as shown by the absence of dyspnea exacerbation for at least 3 months . All patients had conventional transthoracic echocardiography and answered the Minnesota Living with HF Question naire , followed by the 6-min walk test ( 6MWT ) . In a multivariable model with 6MWT as the dependent variable , age and E/e ' explained 27 % of the walked distance in 6MWT ( P=0.002 ; multivariate regression analysis ) . No association was found between walk distance and LVEF or mitral annulus systolic velocity . Only normalized left atrium volume , a sensitive index of diastolic function , was associated with decreased QOL . Despite the small number of patients included , this study offers evidence that diastolic function is associated with physical capacity and QOL and should be considered along with ejection fraction in patients with compensated systolic HF OBJECTIVE To investigate how group-based exercise affects the levels of physical activity , physical fitness and health- related quality of life ( HRQoL ) in patients with chronic heart failure and comorbidities . DESIGN R and omized controlled trial . PATIENTS A total of 48 patients ( 10 women , 38 men ) , mean age 71 years ( st and ard deviation 8 years ) , ejection fraction 27 % ( st and ard deviation 10 % ) , and New York Heart Association functional class II-III . METHODS A bicycle test , 6-min walk test ( 6MWT ) and muscle endurance tests were performed . Physical activity was assessed with a pedometer and the International Physical Activity Question naire ( IPAQ ) , HRQoL was evaluated with the Short Form-36 ( SF-36 ) . Patients were r and omized to control or intervention groups . Intervention consisted of an individually design ed group-based exercise programme twice a week , for a period of 3 months . Subjects in the control group were asked to continue with their usual lives . RESULTS A total of 42 patients completed the study , and 6 dropped-out .  Steps/day did not increase significantly after intervention ( p = 0.351 ) , but IPAQ score did ( p = 0.008 ) . Exercise tolerance ( p = 0.001 ) , 6MWT ( p = 0.014 ) , shoulder abduction ( p = 0.028 ) , heel lift ( p < 0.0001 ) and HRQoL ( p = 0.018 ) improved significantly in the intervention group compared with the control group . CONCLUSION Group-based exercise did not improve the level of physical activity in patients with chronic heart failure and comorbidity ; however , physical fitness and HRQoL were significantly improved The six-minute walk test ( 6MWT ) has been broadly used in clinical setting s. Several reference equations for prediction of the total distance walked during the test ( 6MWD ) are available in literature . The present review aim ed to critically discuss studies , published in Portuguese and English ( LILACS , SCIELO , MEDLINE , PUBMED ) , which evaluated normal values and created reference equations for predicting 6MWD in healthy subjects , comparing them with the results that were recently obtained in Brazilian individuals . Age , sex , weight , height and body mass index were the main demographic and anthropometric features more often correlated with 6MWD . The equations derived from these characteristics were able to explain between 25 and 66 % of the total variability in the 6MWD . Unfortunately , the foreign equations were not applicable to the Brazilian population . Even when the 6MWT was performed following strict st and ardization , the difference in 6MWT performance between foreign and Brazilian individuals remains , indicating the necessity of providing specific reference equations for each population and /or ethnic group . Accordingly , these equations developed in Brazil are probably the most appropriate for interpreting 6MWT performance in Brazilian patients with chronic diseases affecting the exercise capacity . Future studies are necessary with larger sample sizes ( e.g. multicentric ones ) and r and omized design for the reference values of the 6MWD to be considered reliable Background : Atrial fibrillation ( AF ) and heart failure ( HF ) often coexist . The aim was to investigate whether restoring sinus rhythm ( SR ) could improve cardiac function , symptoms , exercise capacity and quality of life ( QoL ) in patients with chronic heart failure . Methods : Patients with HF and persistent AF receiving guideline -recommended treatments , including anticoagulants , were eligible for the study . Patients were r and omised to either rhythm ( treated with amiodarone for at least 3 months prior to attempting biphasic external cardioversion and continued amiodarone long-term if SR was restored ) or rate control . Anticoagulants were continued throughout the study regardless of rhythm , unless contraindications developed . Both groups were treated with beta blockers and /or digoxin to reduce the heart rate to < 80 bpm at rest and < 110 bpm after walking . Symptoms , walk distance ( 6-minute corridor walk test , 6MWT ) , QoL and cardiac function were assessed at baseline and 1 year . Results : 61 patients with HF and persistent AF ( median duration 14 months ( IQR 5 to 32 ) ) were r and omly assigned to a rate or rhythm control strategy . Of patients assigned to rhythm control ( n = 30 ) , 66 % were in SR at 1 year , and 90 % of those assigned to rate control ( n = 31 ) achieved the heart rate target . At 1 year , NYHA class ( p = 0.424 ) and 6MWT distance ( p = 0.342 ) were similar between groups but patients assigned to rhythm control had improved LV function ( p = 0.014 ) , NT-proBNP concentration ( p = 0.046 ) and QoL ( p = 0.019 ) compared with those assigned to rate control . Greatest improvement was seen in patients in whom SR was maintained . Conclusion : Restoring SR in patients with AF and heart failure may improve QoL and LV function when compared with a strategy of rate control BACKGROUND Our purpose was to evaluate the reliability , validity , and responsiveness of the 6-minute walk test ( 6MWT ) in patients with heart failure ( HF ) enrolled in the R and omized Evaluation of Strategies for Left Ventricular Dysfunction ( RESOLVD ) pilot study . METHODS A total of 768 patients was enrolled in a multicenter r and omized clinical trial evaluating the effect of c and esartan , enalapril , and metoprolol on left ventricular ejection fraction ( LVEF ) , 6MWT distance , neurohormones , and quality of life . The 6MWT was performed once at screening and twice at baseline , 18 weeks , and 43 weeks by a st and ardized method . RESULTS Test-retest reliability at baseline ( intraclass correlation coefficient [ ICC ] = 0.90 ) , 18 weeks ( ICC = 0.88 ) , and 43 weeks ( ICC = 0.91 ) was very good . Baseline 6MWT distance was weakly inversely correlated to the quality -of-life cumulative score ( r = -0.26 , P = .0001 ) and moderately inversely correlated to the New York Heart Association functional classification ( NYHA-FC ) ( r = -0.43 , P = .001 ) . In the RESOLVD study , the 6MWT was not responsive to change when effect sizes and st and ardized response means were used . Disease-specific quality of life was responsive to change in patients treated with c and esartan and enalapril and NYHA-FC was responsive to change in the c and esartan and enalapril combination and for enalapril alone with small effect sizes . The 6MWT , NYHA-FC , and quality of life were not responsive to change during the metoprolol or placebo phase . CONCLUSIONS The 6MWT is highly reproducible in patients with symptoms of HF . It is somewhat correlated to NYHA-FC and quality of life . Overall , quality of life was most responsive to change , whereas 6MWT and NYHA-FC were comparable but less responsive to change in the RESOLVD study Background : The incremental shuttle walking test ( SWT ) has recently been proposed as a more valid and reproducible alternative to the conventional 6-min walking test ( 6MWT ) in the evaluation of exercise tolerance in patients with chronic obstructive pulmonary disease ( COPD ) . Objective : To compare the cardiorespiratory performance obtained during two sessions of SWT with that obtained during two sessions of 6MWT . Methods : We examined 18 patients ( forced expiratory volume in 1 s : 48 ± 14 % ) recovering from an acute exacerbation of COPD that had required hospitalization . In the same afternoon , each patient performed two SWT and two 6MWT , with an interval of at least 30 min between each test ; the sequence of the tests was r and omized . Results : Mean walking distance was greater in the second SWT test than in the first SWT . The changes from baseline in systolic blood pressure , heart rate , respiratory rate , oxygen saturation and dyspnea Borg index at the end of the test were similar between the two 6MWT and the two SWT . There was a highly significant correlation between walking distances measured during SWT and during 6MWT ( ρ : 0.85 , p < 0.0005 ) . Neither SWT nor 6MWT correlated with functional data of COPD . Conclusions : SWT , though being considered to be closer to a submaximal exercise test than 6MWT , does not induce a greater cardiorespiratory performance  than 6MWT in patients recovering from acute exacerbation of COPD BACKGROUND Providing flexible models and a variety of exercise options are fundamental to supporting long-term exercise participation for patients with heart failure ( HF ) . The aim of this pilot study was to determine the feasibility and efficacy of aquatic exercise training during a maintenance phase for a clinical heart failure population . METHODS In this 2 x 2 crossover design trial , individuals who had previously completed HF rehabilitation were r and omised into either a l and -based or aquatic training program once per week for six weeks , after which time they changed to the alternate exercise training protocol for an additional six weeks . Six-minute walk test ( 6MWT ) , grip strength , walk speed , and measures of balance were compared for the two training protocol s. RESULTS Fifty-one participants ( 43 males , mean age 69.2 yrs ) contributed data for the analysis . Both groups maintained function during the follow-up period , however improvements in 6MWT were greater in the l and -based training group ( 95 % CI : 0.7 , 22.5 ; p=0.038 ) , by a mean difference of 10.8 metres . No significant difference was observed for other parameters when the two training protocol s were compared . CONCLUSION Attending an aquatic exercise program once per week is feasible for patients with stable HF and may provide a suitable option to maintain functional performance in select patients Decreased HRV has been consistently associated with increased cardiac mortality and morbidity in HF patients . The aim of this study is to determine if a 6-week course of heart rate variability ( HRV ) biofeedback and breathing retraining could increase exercise tolerance , HRV , and quality of life in patients with New York Heart Association Class I-III heart failure ( HF ) . Participants ( N = 29 ) were r and omly assigned to either the treatment group consisting of six sessions of breathing retraining , HRV biofeedback and daily practice , or the comparison group consisting of six sessions of quasi-false alpha-theta biofeedback and daily practice . Exercise tolerance , measured by the 6-min walk test ( 6MWT ) , HRV , measured by the st and ard deviation of normal of normal beats ( SDNN ) , and quality of life , measured by the Minnesota Living with Congestive Heart Failure Question naire , were measured baseline ( week 0 ) , post ( week 6 ) , and follow-up ( week 18 ) . Cardiorespiratory biofeedback significantly increased exercise tolerance ( p = .05 ) for the treatment group in the high ( ≥31 % ) left ventricular ejection fraction ( LVEF ) category between baseline and follow-up . Neither a significant difference in SDNN ( p = .09 ) nor quality of life ( p = .08 ) , was found between baseline and follow-up . A combination of HRV biofeedback and breathing retraining may improve exercise tolerance in patients with HF with an LVEF of 31 % or higher . Because exercise tolerance is considered a strong prognostic indicator , cardiorespiratory biofeedback has the potential to improve cardiac mortality and morbidity in HF patients Background : This study aim ed to determine whether morbidly obese women have an alteration of heart rate ( HR ) kinetics and HR variability ( HRV ) during the 6-min walk test ( 6MWT ) and if an aerobic exercise training can modify these indexes after gastric bypass surgery ( GBS ) . Design and methods : Nineteen morbidly obese women were r and omized to a trained ( TG ) or control group and 12 women of eutrophic group ( EG ) were also evaluated . The obese women were tested on two occasions : 1 week before and 4 months after GBS through record of HR and R-R intervals during 6MWT for analysis HR kinetics . The TG underwent an aerobic exercise training program on a treadmill ( 1-h session , totaling 36 sessions over 12-week ) . Results : Both obese groups demonstrated a significant reduction of rMSSD and slower HR kinetics during the 6MWT when compared to the EG . In addition , only the TG demonstrated a significant improvement in HRV indexes , walking distance , faster time constant and mean response time of HR during 6MWT after training ( p < 0.05 ) . Conclusion : Morbidly obese women have slower HR kinetics and altered cardiac modulation during submaximal exercise . However , aerobic exercise training can produce beneficial adaptations in HRV and faster HR kinetics following GBS . Implication s for Rehabilitation The obesity is one of the most important threats to health in developed countries and bariatric surgery is an option for treatment of morbid obesity . Exercise is an effective means of improving health after this procedure due alterations of autonomic nervous system in this population . This study showed that a program of aerobic physical training after bariatric surgery was able to improve the kinetics of heart rate and the cardiac autonomic modulation , both evaluated during submaximal exercise Background : The responsiveness of the endurance shuttle walk to functional changes following bronchodilation has recently been reported . The current literature suggests that the 6 min walking test ( 6MWT ) is less responsive to bronchodilation than the endurance shuttle walk . Aim : To compare bronchodilator-induced changes in exercise performance with the 6MWT and the endurance shuttle walk . Methods : In a r and omised , double-blind , placebo-controlled , crossover trial , 14 patients with chronic obstructive pulmonary disease ( forced expiratory volume in 1 s ( FEV1 ) 50 (8)% predicted ) completed two 6MWTs and two endurance shuttle walks , each preceded by nebulised placebo or 500 μg ipratropium bromide .  Cardiorespiratory parameters were monitored during each walking test with a portable telemetric gas analyser . Quadriceps twitch force was measured by magnetic stimulation of the femoral nerve before and after each walking test . Results : The 6 min walking distance did not change significantly after bronchodilation despite a significant increase in FEV1 of 0.18 ( 0.09 ) litres ( p<0.001 ) . A similar change in FEV1 ( 0.18 ( 0.12 ) litres , p<0.001 ) was associated with a significant improvement in the distance walked on the endurance shuttle walk ( Δdistance ipratropium bromide – placebo = 144 ( 219 ) m , p = 0.03 ) . Quadriceps muscle fatigue was infrequent ( < 15 % of patients ) after both walking tests . Conclusion : The endurance shuttle walk is more responsive than the 6MWT for detecting changes in exercise performance following bronchodilation Aim The aim of this study was to evaluate the benefits and safety of long-term i.v . iron therapy in iron-deficient patients with heart failure ( HF ) . Methods and results CONFIRM-HF was a multi-centre , double-blind , placebo-controlled trial that enrolled 304 ambulatory symptomatic HF patients with left ventricular ejection fraction ≤45 % , elevated natriuretic peptides , and iron deficiency ( ferritin < 100 ng/mL or 100–300 ng/mL if transferrin saturation < 20 % ) . Patients were r and omized 1 : 1 to treatment with i.v . iron , as ferric carboxymaltose ( FCM , n = 152 ) or placebo ( saline , n = 152 ) for 52 weeks . The primary end-point was the change in 6-min-walk-test ( 6MWT ) distance from baseline to Week 24 . Secondary end-points included changes in New York Heart Association ( NYHA ) class , Patient Global Assessment ( PGA ) , 6MWT distance , health-related quality of life ( QoL ) , Fatigue Score at Weeks 6 , 12 , 24 , 36 , and 52 and the effect of FCM on the rate of hospitalization for worsening HF . Treatment with FCM significantly prolonged 6MWT distance at Week 24 ( difference FCM vs. placebo : 33 ± 11 m , P = 0.002 ) . The treatment effect of FCM was consistent in all subgroups and was sustained to Week 52 ( difference FCM vs. placebo : 36 ± 11 m , P < 0.001 ) . Throughout the study , an improvement in NYHA class , PGA , QoL , and Fatigue Score in patients treated with FCM was detected with statistical significance observed from Week 24 onwards . Treatment with FCM was associated with a significant reduction in the risk of hospitalizations for worsening HF [ hazard ratio ( 95 % confidence interval ) : 0.39 ( 0.19–0.82 ) , P = 0.009 ] . The number of deaths ( FCM : 12 , placebo : 14 deaths ) and the incidence of adverse events were comparable between both groups . Conclusion Treatment of symptomatic , iron-deficient HF patients  with FCM over a 1-year period result ed in sustainable improvement in functional capacity , symptoms , and QoL and may be associated with risk reduction of hospitalization for worsening HF ( Clinical Trials.gov number NCT01453608 ) Objective . The 6-minute walk test ( 6MWT ) is an important prognostic tool in various cardiovascular diseases and has been considered as a surrogate endpoint . However , conflicting results have been reported in systemic sclerosis ( SSc ) . Our objective was to evaluate the relationships of the 6-min walking distance  ( 6MWD ) and organ damage in SSc . Methods . Eighty-seven consecutive patients with SSc were included and prospect ively investigated ; they underwent 6MWT in addition to conventional assessment of possible lung , heart , kidney , skin , and muscle involvement , and disease activity scoring , severity , and quality of life determination . Results . Twenty-six patients ( 30 % ) had an abnormal 6MWT and the mean 6MWD was 461.8 ± 103.0 m. When considering 6MWT as a binary variable — normal or abnormal — C-reactive protein ( CRP ) was the only independent variable associated with abnormal 6MWT . Considered as a continuous variable , the 6MWD was associated with measures of lung involvement and inflammation , with the activity and severity of disease , and also with quality of life ; nevertheless , calcinosis was the only independent factor associated in multivariate analyses with a trend for an association for CRP . Conclusion . The 6MWD relates to broad factors in SSc and these results raise doubts about the specificity of the 6MWD in this systemic disease , and its relevance to monitoring therapy OBJECTIVE To compare the effects of an 8-week , high-intensity interval training protocol versus continuous training . DESIGN R and omized controlled trial . SETTING Cardiac rehabilitation center . PARTICIPANTS Patients ( N=26 ; mean age ± SD , 54±12y ) with chronic heart failure were enrolled in a cardiac rehabilitation program for 8 weeks . INTERVENTIONS Patients were r and omly assigned into 2 groups that performed either interval training ( IT ) or continuous training ( CT ) . IT consisted of 3 sessions of 12 repetitions of 30 seconds of exercise at very high intensity , followed by 60 seconds of complete rest . The CT group performed CT exercises , which consisted of 45 minutes of aerobic exercise . MAIN OUTCOME MEASURES Parameters of gas exchanges : peak oxygen consumption ( Vo(2)peak ) , first ventilator threshold ( VT1 ) , distance at six-minute walk test ( 6MWT ) , and level of anxiety and depression were measured . RESULTS The IT group increased significantly their Vo(2)peak , the duration of the exercise test , the oxygen pulse , oxygen consumption at the VT1 , and the distance walked during the 6MWT . The CT group only increased the time at the VT1 and the distance performed at the 6MWT . The improvement in the time at the VT1 was significantly higher for the IT group than for the CT group . CONCLUSIONS This study shows that IT at very high intensity for patients with heart failure appears to be more effective than CT in improving indices of submaximal exercise capacity
Pharmacological trials including patients with more severe heart failure were more likely to show a significant improvement with therapy than trials of milder heart failure .
Using mean values in these trials , the age of patients appeared a more important determinant of 6MWT distance than New York Heart Association classification .
The 6MWT has not yet been proven to be a robust test for the identification of effective pharmacological interventions although it appears useful for the assessment of cardiac resynchronization therapy .
The results of the 6MWT were concordant with changes in symptoms , suggesting that it may be used as supportive evidence for symptom benefit .
AIMS The 6 min walk test ( 6MWT ) is commonly used in clinical trials to assess treatments for heart failure , but its ability to distinguish between effective and ineffective treatments is question able .
The aim of this study is to investigate , using a systematic literature review , the utility of the 6MWT as a measure of the effectiveness of treatment in r and omized controlled trials of heart failure .