Reliability, validity, and responsiveness of the six-minute walk test in patients with heart failure. Six-Minute Walk Test and Cardiopulmonary Exercise Testing in Patients With Chronic Heart Failure: A Comparative Analysis on Clinical and Prognostic Insights Which field walking test should be used to assess functional exercise capacity in lung cancer? an observational study Randomized trial of Nordic walking in patients with moderate to severe heart failure. Relation of Longitudinal Changes in Quality of Life Assessments to Changes in Functional Capacity in Patients With Heart Failure With and Without Anemia. Six-minute-walk test in idiopathic pulmonary fibrosis: test validation and minimal clinically important difference. Daily walking performance as an independent predictor of advanced heart failure: Prediction of exercise capacity in chronic heart failure. Regression equations to predict 6-minute walk distance in middle-aged and elderly adults [Reference Equations for the 6-Minute Walk Test in Healthy Individuals.] Validity and reliability of the modified shuttle walk test in patients with chronic obstructive pulmonary disease. Updated assessment of the six-minute walk test as predictor of acute radiation-induced pneumonitis. No effect of group-based aerobic interval training on N-terminal pro- B-type natriuretic peptide levels in patients with chronic heart failure Pentraxin-3 Predicts Functional Recovery and 1-Year Major Adverse Cardiovascular Events After Rehabilitation of Cardiac Surgery Patients Impaired 6-min walk test, heart rate recovery and cardiac function post pulmonary embolism in long-term survivors. Submaximal exercise in persons with stroke: test-retest reliability and concurrent validity with maximal oxygen consumption. Repeat six-minute walk tests in patients with chronic heart failure: are they clinically necessary? Group-based Aerobic Interval Training in Patients With Chronic Heart Failure: Norwegian Ullevaal Model Effect of Bariatric Surgery on the Six-Minute Walk Test in Severe Uncomplicated Obesity Maximum daily 6 minutes of activity: an index of functional capacity derived from actigraphy and its application to older adults 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 Course length of 30 metres versus 10 metres has a significant influence on six-minute walk distance in patients with COPD: an experimental crossover study. Cardiac rehabilitation in chronic heart failure: effect of an 8-week, high-intensity interval training versus continuous training. Influence of creatine supplementation on the functional capacity of patients with heart failure.
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 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 Background There is emerging evidence regarding the efficacy of exercise training to improve exercise capacity for individuals with non-small cell lung cancer ( NSCLC ) .  Cardiopulmonary exercise testing ( CPET ) is the gold st and ard measure of exercise capacity ; however this laboratory test has limitations for use in research and clinical practice . Alternative field walking tests are the six-minute walk test ( 6MWT ) , incremental-shuttle walk test ( ISWT ) and endurance-shuttle walk test ( ESWT ) ; however there is limited information about their clinimetric properties in NSCLC . Aims : In NSCLC to determine the 1 ) criterion validity of the 6MWT , ISWT and ESWT against CPET ; 2 ) construct validity of the 6MWT , ISWT and ESWT against measures of function , strength , respiratory function and health-related quality of life ( HRQoL ) ; and 3 ) clinical applicability of the tests . Methods Twenty participants ( 40 % male , mean ± SD age 66.1 ± 6.5 years ) with stage I-IIIb NSCLC completed the 6MWT , ISWT , ESWT and CPET within six months of treatment . Testing order was r and omised . Additional measures included Eastern Cooperative Oncology Group Performance-Status ( ECOG-PS , function ) , respiratory function , h and -grip dynamometry and HRQoL. Correlations and regression analyses were used to assess relationships . Results The ISWT demonstrated criterion validity with a moderate relationship between ISWT distance and CPET peak oxygen consumption ( r = 0.61 , p = 0.007 ) . Relationships between CPET and six minute walk distance ( 6MWD ) ( r = 0.24 , p = 0.329 ) or ESWT time ( r = 0.02 , p = 0.942 ) were poor . Moderate construct validity existed for the 6MWD and respiratory function ( forced vital capacity % predicted r = 0.53 , p = 0.019 ; forced expiratory volume in the first second % predicted r = 0.55 , p = 0.015 ) . There were no relationships between the walking tests and measures of function , strength or HRQoL. The ESWT had a ceiling effect with 18 % reaching maximum time . No floor effects were seen in the tests . The mean ± SD time required to perform the individual 6MWT , ISWT and ESWT was 12.8 ± 2.5 , 14.7 ± 3.7 and 16.3 ± 5.0 min respectively ; in comparison to CPET which was 51.2 ± 12.7 min . Only one assessor was required to perform all field walking tests and no adverse events occurred . Conclusions The ISWT is a promising measure of functional exercise capacity in lung cancer . Findings need to be confirmed in a larger sample prior to translation into practice BACKGROUND Patients with heart failure are a growing population within cardiac rehabilitation . The purpose of this study was to compare , through a single-centre , parallel-group , r and omized controlled trial , the effects of Nordic walking and st and ard cardiac rehabilitation care on functional capacity and other outcomes in patients with moderate to severe heart failure . METHODS Between 2008 and 2009 , 54 patients ( aged 62.4 ± 11.4 years ) with heart failure ( mean ejection fraction = 26.9 % ± 5.0 % ) were r and omly assigned to st and ard cardiac rehabilitation care ( n = 27 ) or Nordic walking ( n = 27 ) ; both groups performed 200 to 400 minutes of exercise per week for 12 weeks . The primary outcome , measured after 12 weeks , was functional capacity assessed by a 6-minute walk test ( 6MWT ) . RESULTS Compared with st and ard care , Nordic walking led to higher functional capacity ( Δ 125.6 ± 59.4 m vs Δ 57.0 ± 71.3 m travelled during 6MWT ; P = 0.001 ) , greater self-reported physical activity ( Δ 158.5 ± 118.5 minutes vs Δ 155.5 ± 125.6 minutes ; P = 0.049 ) , increased right grip strength ( Δ 2.3 ± 3.5 kg vs Δ 0.3 ± 3.1 kg ; P = 0.026 ) , and fewer depressive symptoms ( Hospital Anxiety and Depression Scale score = Δ -1.7 ± 2.4 vs Δ -0.8 ± 3.1 ; P = 0.014 ) . No significant differences were found for peak aerobic capacity , left-h and grip strength , body weight , waist circumference , or symptoms of anxiety . CONCLUSIONS Nordic walking was superior to st and ard cardiac rehabilitation care  in improving functional capacity and other important outcomes in patients with heart failure . This exercise modality is a promising alternative for this population 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 RATIONALE The 6-minute-walk test ( 6MWT ) is a practical and clinical ly meaningful measure of exercise tolerance with favorable performance characteristics in various cardiac and pulmonary diseases . Performance characteristics in patients with idiopathic pulmonary fibrosis ( IPF ) have not been systematic ally evaluated . OBJECTIVES To assess the reliability , validity , and responsiveness of the 6MWT and estimate the minimal clinical ly important difference ( MCID ) in patients with IPF . METHODS The study population included all subjects completing a 6MWT in a clinical trial evaluating interferon gamma-1b ( n = 822 ) .  Six-minute walk distance ( 6MWD )  and other parameters were measured at baseline and at 24-week intervals using a st and ardized protocol . Parametric and distribution-independent correlation coefficients were used to assess the strength of the relationships between 6MWD and measures of pulmonary function , dyspnea , and health-related quality of life . Both distribution-based and anchor-based methods were used to estimate the MCID . MEASUREMENTS AND MAIN RESULTS Comparison of two proximal measures of 6MWD ( mean interval , 24 d ) demonstrated good reliability ( coefficient = 0.83 ; P < 0.001 ) . 6MWD was weakly correlated with measures of physiologic function and health-related quality of life ; however , values were consistently and significantly lower for patients with the poorest functional status , suggesting good construct validity . Importantly , change in 6MWD was highly predictive of mortality ; a 24-week decline of greater than 50 m was associated with a fourfold increase in risk of death at 1 year ( hazard ratio , 4.27 ; 95 % confidence interval , 2.57- 7.10 ; P < 0.001 ) . The estimated MCID was 24 - 45 m. CONCLUSIONS The 6MWT is a reliable , valid , and responsive measure of disease status and a valid endpoint for clinical trials in IPF 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 Six-minute walk distance ( 6MWD ) is commonly used as a measure of functional exercise capacity in clinical practice and research . Regression equations to predict 6MWD in healthy individuals are available , but the equations predict distances that vary considerably for an individual . The aims of this study were to 1 ) measure 6MWDs in healthy Caucasian Australians aged 45 - 85 years ; 2 ) determine whether evidence exists for Australian-specific prediction equations for Caucasian individuals by comparing measured 6MWDs with predicted 6MWDs derived by using published regression equations ; and 3 ) develop regression equations for males and females . One hundred nine subjects ( 48 males ) completed the 6-minute walk test ( 6MWT ) . Measurements of height , leg length , weight , habitual physical activity , and peak heart rate ( HR ) achieved during the 6MWT were obtained . 6MWD ( better of two tests ) was 682 ± 73 m ( mean ± SD ) and 643 ± 70 m in the males and females , respectively ( p<0.01 ) . Published regression equations underestimated 6MWDs in female subjects . Gender-specific regression equations using age and anthropometric data explained 40 % and 43 % of the variance in 6MWD in males and females , respectively . Validation of the regression equations in a prospect i ve subject cohort is required 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 OBJECTIVES ( 1 ) To examine the concurrent criterion validity of the modified shuttle walk test ( MSWT ) by using the 6- ( 6MWT ) and 12-minute walk test ( 12MWT ) , ( 2 ) to examine the concurrent criterion validity of the estimated maximum oxygen uptake ( Vo2max ) of the MSWT with actual Vo2max , and ( 3 ) to determine test-retest reliability of the MSWT in patients with chronic obstructive pulmonary disease ( COPD ) . DESIGN Validation study . SETTING Outpatient pulmonary rehabilitation program . PARTICIPANTS Thirty clinical ly stable adults with COPD . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Subjects were r and omly assigned to receive either the 6MWT and 12MWT or the MSWT first . The MSWT was repeated 1 week later ( N = 30 ) . Estimated Vo2max was calculated , and actual Vo2max was conducted by using the Jones test . Validity of the MSWT was assessed by comparing endurance scores and Vo2max with results from the 6MWT and 12MWT and Jones test , respectively . RESULTS There was a moderately high correlation between the  MSWT  and the 6MWT and 12MWT at initial testing ( .82 and .74 , respectively ) . Correlation between estimated and actual Vo2max was r equal to .68 . Test-retest reliability for the entire sample was high ( intraclass correlation coefficient , .88 ) . Results remained quite stable across severity , age , and sex subgroups . CONCLUSIONS The MSWT is a st and ardized externally paced submaximal endurance walking test . The results indicate that the MSWT has high concurrent validity and test-retest reliability for patients with COPD PURPOSE To assess the utility of the 6-minute walk test ( 6MWT ) as a predictor of  symptomatic radiation-induced pneumonitis ( RP ) .  METHODS As part of a prospect i ve trial to study radiation-induced lung injury , 53 patients receiving thoracic radiotherapy ( RT ) underwent a pre-RT 6MWT , pulmonary function tests ( PFTs ) , and had > or=3-month follow-up for prospect i ve assessment of Grade 2 or worse RP ( requiring medications or worse ) . Dosimetric parameters ( e.g. , the percentage of lung receiving > or=30 Gy ) were extracted from the lung dose-volume histogram . The correlations between the 6MWT and PFT results were assessed using Pearson 's correlation . The receiver operating characteristic technique was used in patient subgroups to evaluate the predictive capacities for RP of the dosimetric parameters , 6MWT results , and PFT results , or the combination ( using discriminant analysis ) of all three metrics . ROCKIT software was used to compare the receiver operating characteristic areas between each predictive model . The association of the decline in 6MWT with the development of RP was evaluated using Fisher 's exact test . RESULTS The pre-RT PFT and 6MWT results correlated weakly ( r = 0.44 - 0.57 , p < or= 0.001 ) , suggesting that they measure somewhat different physiologic functions . Of the 53 patients , 9 ( 17 % ) developed RP . The dose-volume histogram-based dosimetric parameters were the best single-metric model for predicting RP ( e.g. , percentage of lung receiving > or=30 Gy , receiver operating characteristic area 0.73 , p = 0.03 ) . Including the PFT or 6MWT results with the percentage of lung receiving > or=30 Gy did not improve the predictions . The predictive abilities of dosimetric-based models improved when the analysis was restricted to those patients whose tumors were not causing regional lung dysfunction . No correlation was found between the decline in the 6MWT result and the RP rate ( p = 0.6 ) . CONCLUSION Although the PFTs and 6MWT are related to each other , the correlation coefficients were weak , suggesting that they could be measuring different physiologic functions . In the present data set , the addition of the PFTs or 6MWT did not increase the ability of the dosimetric parameters to predict for acute symptomatic RP . Additional work is needed to better underst and the interaction among the PFT results , exercise tolerance ( 6MWT ) , and the risk of RT-induced  lung dysfunction Abstract Objectives . Exercise training might improve cardiac function as well as functional capacity in patients with chronic heart failure ( CHF ) . N-terminal pro-B-type natriuretic peptide ( NT pro-BNP ) , is associated with the severity of the disease , and has been reported to be an independent predictor of outcome in CHF . We evaluated the effect of a four months group-based aerobic interval training program on circulating levels of NT pro-BNP in patients with CHF . We have previously reported improved functional capacity in 80 patients after exercise in this exercise program . Methods . Seventy-eight patients with stable CHF ( 21 % women ; 70±8 years ; left ventricular ejection fraction 30±8.6 % ) on optimal medical treatment were r and omized either to interval training  ( n=39 ) , or to a control group  ( n=39 ) . Circulating levels of NT pro-BNP , a six minute walk test ( 6MWT ) and cycle ergometer test were evaluated at baseline , post exercise , and further after 12 months . Results . There were no significant differences in NT pro-BNP levels from baseline to either post exercise or long-term follow-up between or within the groups . Inverse correlations were observed between NT pro-BNP and 6MWT ( r=−0.24 , p=0.035 ) and cycle exercise time ( r=−0.48 , p<0.001 ) at baseline . But no significant correlations were observed between change in NT pro-BNP and change in functional capacity ( 6MWT ; r=0.12 , p=0.33 , cycle exercise time ; r=0.04 , p=0.72 ) . Conclusion . No significant changes in NT pro-BNP levels were observed after interval training , despite significant improvement of functional capacity BACKGROUND : Inflammatory and vascular markers have proved to be predictors of outcome in myocardial infa rct ion and heart failure . We evaluated several circulating markers of cardiac stress , inflammation , and endothelial function to investigate their ability to predict short-term functional recovery and long-term clinical outcome in heart surgery patients undergoing inpatient rehabilitation . METHODS : This prospect i ve , multicenter study enrolled 223 patients after heart surgery , included in a 3-week program of st and ardized and supervised physical training .  The association between biomarkers ( pentraxin-3 [ PTX3 ] , brain natriuretic peptide , high-sensitivity cardiac troponin-T [ hs-cTnT ] and C-reactive protein [ hsCRP ] , creatine kinase , myoglobin , and urinary albumin excretion [ UACR ] ) and exercise capacity ( 6-minute walk test , 6MWT ) or 1-year incidence of major adverse cardiovascular events ( MACE ) was tested in models that included biohumoral markers , and clinical and instrumental variables . RESULTS : The patients ( 69.5 % men , mean age of 67 ± 11 years ) were enrolled after valvular surgery ( 52.7 % ) and 58.6 % after coronary artery bypass grafting ( CABG ) . Exercise capacity improved during rehabilitation ( 6MWT distance from 279 ± 95 to 386 ± 91 m ; P < .0001 ) ; concentrations of most biomarkers decreased ( hsCRP : 79 % [ P < .0001 ] ; hs-cTnT : 57 % [ P < .0001 ] ; UACR : 36 % [ P = .05 ] ) . Among the tested markers , PTX3 showed the closest association with 6MWT distance ( P = .01 ) and was the only predictor of MACE , also in the subgroup of CABG patients ( OR [ 95 % CI ] = 1.14 [ 1.03–1.27 ] ; P = .015 ) . CONCLUSION : PTX3 , a marker of vascular inflammation and cardiovascular damage , is a predictor of short-term functional recovery and 1-year MACE in patients undergoing rehabilitation after cardiac surgery , regardless of clinical and instrumental parameters BACKGROUND The functional capacity of long-term survivors of submassive pulmonary embolism ( PE ) is unreported . A six-minute walk distance ( 6MWD ) < 350 m and reduced heart rate recovery ( HRR ) indicate adverse prognosis in various chronic diseases . METHODS Long-term survivors of acute PE ( January 2000-June 2005 ) were invited to undergo prospect ively planned six-minute walk test ( 6MWT ) , transthoracic echocardiogram ( TTE ) , clinical and biochemical evaluation with cardiac biomarkers .  HRR was calculated as the difference between heart rate at 6-min during and at 1-min post 6MWT . RESULTS 120 patients ( 52 males ; mean age [ ±st and ard deviation ] - 65 ± 14 years ) were identified 7.7 ± 1.4 years after PE . 6MWD was significantly lower than that predicted after adjustment for age , sex , and height ( 448 ± 114 m vs 475 ± 89 m , p = 0.005 ) , and 16 % ( 17/104 ) had 6MWD < 350 m. Among patients with no baseline comorbidities at follow-up ( Charlson comorbidity index = 0 ) , 8 % ( 4/52 ) had 6MWD < 350 m. Resting TTE identified 29 % of patients had raised right ventricular ( RV ) pulmonary pressure ( pulmonary arterial systolic pressure [ PASP ] > 36 mmHg ) and 13 % had impaired RV function . Patients with 6MWD < 85 % predicted had significantly greater impairment of RV longitudinal function ( p < 0.001 ) , higher PASP ( p < 0.001 ) and pulmonary vascular resistance ( p < 0.001 ) , elevated NT-proBNP ( p = 0.03 ) and high-sensitivity troponin-T ( HsTropT , p = 0.03 ) , but similar left ventricular systolic and diastolic function , to those with normal 6MWT . CONCLUSIONS Apparently well , long-term survivors of PE demonstrate impaired exercise capacity , heart rate recovery , mild pulmonary hypertension , raised PVR and right ventricular dysfunction associated with elevated NT-proBNP and OBJECTIVE To establish the test-retest reliability and concurrent validity with maximum oxygen consumption ( VO2max ) for 3 submaximal exercise tests in persons with chronic stroke : ( 1 ) submaximal treadmill test , ( 2 ) submaximal cycle ergometer test , and ( 3 ) 6-minute walk test ( 6MWT ) . DESIGN Prospect i ve study using a convenience sample . SETTING Free-st and ing tertiary rehabilitation center . PARTICIPANTS A volunteer sample of 12 community-dwelling individuals who had a stroke with moderate motor deficits . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Heart rate , blood pressure , and oxygen consumption ( VO2 ) were assessed during the exercise tests . RESULTS Test-retest reliability was good to excellent for the exercise tests ( maximal and submaximal tests ) . VO2 for all submaximal measures related to VO2max ( r range , .66-.80 ) . Neither the 6MWT distance , self-selected gait speed , nor hemodynamic measures related to VO2max . CONCLUSION The VO2 measures of the submaximal exercise tests had excellent reliability and good concurrent validity with VO2max . Submaximal exercise tests may be a method by which to monitor the effects of interventions after a screening test ( eg , symptom-limited grade d exercise test , dobutamine stress echocardiograph ) 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 and Purpose : The purpose of this case report is to describe the responses of 4 patients with chronic heart failure ( CHF ) to a novel rehabilitation program : a group-based , high-intensity , interval-training program that includes aerobic , resistance , flexibility , and balance activities . Case Descriptions : Four patients ( 55–71 years of age ) with CHF ( New York Heart Association class III ) participated in the rehabilitation program twice per week for 16 weeks . Outcome measures included a 6-minute walk test ( 6MWT ) , a cycle ergometer test ( aerobic capacity ) , and a quality -of-life question naire . Outcomes : Patients 1 , 2 , and 3 increased their aerobic capacity ( 17 % , 25 % , and 52 % , respectively ) . Patient 4 did not complete the cycle ergometer test because of limitations associated with his pacemaker . All patients increased their 6MWT distance ( 117 , 66 , 135 , and 143 m for patients 1 , 2 , 3 , and 4 , respectively ) . No adverse events were reported . Discussion : The Norwegian Ullevaal Model of cardiac rehabilitation is a novel high-intensity , interval-training program . The 4 patients with CHF in this case series who participated in this program experienced improvements in physical capacity and quality of life and had no adverse events . These results are consistent with recent evidence supporting the efficacy of high-intensity interval training in people with CHF . R and omized clinical trials are needed to evaluate the clinical efficacy of this group-based , high-intensity , aerobic interval-training program for patients with CHF Background : The six-minute walk test ( 6mWT ) is a simple index of functional capacity in healthy people , and it has been used to estimate exercise capacity in obese subjects . The aim of this study was to determine whether weight reduction induced by laparoscopic adjustable gastric b and ing ( LAGB ) improves the functional capacity in the severely obese on the 6mWT . Methods : A prospect i ve 1-year study was carried out at the Hospital Casoria , Naples , involving 15 consecutive severely obese patients who underwent the 6mWT before and 1 year after LAGB .  BMI , walking distance , heart rate , dyspnea , and respiratory function tests were also measured . Patients served as their own controls . Results : 15 patients ( all females ) were evaluated .  Mean BMI decreased from 42.1 ( range 39 - 49 ) before to 31.9 ( range 25 - 38 ) postoperatively . The distance walked increased from 475.7 meters ( range 380 - 580 ) before LAGB to 626.3 meters ( range 435 - 880 ) 1 year postoperatively ( P<0.0001 ) , and the dyspnea score after the 6mWT was significantly reduced postoperatively . All functional variables after the 6mWT showed improvement postoperatively at 1 year study . Conclusion : Weight reduction in the obese increases the functional capacity during walking . The improvements are refected in the patients ' own assessment OBJECTIVES To compare the correlation between the maximum 6 minutes of daily activity ( M6min ) and st and ard measures of functional capacity in older adults with heart failure ( HF ) with that in younger subjects and its prognostic utility . DESIGN Prospect i ve , cohort study . SETTING Tertiary care , academic HF center . PARTICIPANTS Sixty , ambulatory , adults , New York Heart Association ( NYHA ) Class I to III , stratified into young ( 50.9 + /- 9.4 ) and older cohorts ( 76.8 + /- 8.0 ) . MEASUREMENTS Correlation between M6min and measures of functional capacity ( 6-minute walk test ; 6MWT ) and peak oxygen consumption ( VO(2 ) ) according to cardiopulmonary exercise testing in a subset of subjects . Survival analysis was employed to evaluate the association between M6min and adverse events . RESULTS  Adherence  to actigraphy was high ( 90 % ) and did not differ according to age . The correlation between M6min and 6MWT was higher in subjects aged 65 and older than in those younger than 65 ( correlation coefficient ( r=0.702 , P<.001 vs r=0.490 , P=.002 ) . M6min was also significantly associated with peak VO(2 ) ( r=0.612 , P=.006 ) . During the study , 26 events occurred ( 2 deaths , 10 hospitalizations , 8 emergency department visits , and 6 intercurrent illnesses ) . The M6min was significantly associated with subsequent events ( hazard ratio=2.728 , 95 % confidence interval=1.10 - 6.77 , P=.03 ) , independent of age , sex , ejection fraction , NYHA class , brain natriuretic peptide , and 6MWT . CONCLUSION The high adherence to actigraphy and association with st and ard measures of functional capacity and independent association with subsequent morbid events suggest that it may be useful for monitoring older adults with HF 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 QUESTIONS Do patients with chronic obstructive pulmonary disease ( COPD ) achieve a different distance on the six minute walk test ( 6MWT ) conducted on a 10 m course versus on a 30 m course ? When assessing the distance on a 6MWT conducted on a 10 m course , is it valid to use existing reference equations that were generated on longer courses ? DESIGN A r and omised double-crossover experimental study . PARTICIPANTS Forty-five patients with COPD in primary physiotherapy care . INTERVENTION All patients performed a 6MWT twice over a 10 m course and twice over a 30 m course . The 6MWTs were performed in accordance with the American Thoracic Society guidelines . OUTCOME MEASURES 6MWD was assessed and predicted distance was calculated based on a range of reference equations . RESULTS The 6MWD on the 10 m course was 49.5 m shorter than on the 30 m course , which was statistically significant ( 95 % CI 39.4 to 59.6 ) . By using existing reference equations for a 6MWT conducted on the 10 m course , the predicted distance is highly overestimated ( with a range of 30 % to 33 % ) and the average distance as a percentage of the predicted value is 8%pred lower compared to a 6MWT conducted on the 30 m course , result ing in a worse representation of a COPD patient 's functional exercise capacity . CONCLUSION This study shows that the impact of course length on the 6MWD and on the use of reference equations in patients with COPD is substantial and clinical ly relevant ( based on the most conservative published minimum clinical ly important difference ) . Therefore , existing reference equations established for a 6MWT conducted over a 30 m ( or longer ) course can not be applied to predict the distance achieved on the 6MWT on a 10 m course , which is frequently used in primary care physiotherapy practice s for patients with COPD 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 BACKGROUND Heart failure ( HF ) is a complex syndrome characterized by intolerance to exertion and reduced functional capacity . OBJECTIVE To assess the functional capacity of patients with HF and supplemented with creatine .  METHODS Prospect i ve , r and omized , double-blind study . Thirty-three male patients over the age of 18 years with functional class II to IV HF were r and omized into two groups as follows : the experimental group ( CRE , n = 17 ) , supplemented with 5 g/day of creatine for six months ; and the placebo group ( PLA , n = 16 ) , receiving 5 g/day of maltodextrin for that same period . Both groups underwent functional capacity assessment by use of cardiopulmonary exercise test and 6-minute walk test ( 6MWT ) before and after the intervention . The Ancova statistical model and Pearson correlation were used to assess the groups and the treatment . RESULTS Of the variables assessed on the cardiopulmonary exercise test , peak oxygen consumption ( peak VO₂ ) , anaerobic threshold ( AT ) , and oxygen pulse ( O₂ pulse ) showed no significant differences between the groups ( P>0.05 ) . On the 6MWT , no significant difference was observed in the covered distance . CONCLUSION Creatine supplementation in patients with HF did not significantly improve functional capacity
Comparison of the studies investigating reliability shows that the 6MWT has good reproducibility .
The 6MWT demonstrates moderate correlation with peak VO(2 ) levels , and ability to predict VO(2 ) ( functional capacity ) dependent on distance walked .
Cut-off distances vary from 300 to 490 meters depending on the study ; if total distance walked remains equal or less than these values , the 6MWT retains its strong predictive value .
The 6MWT has good reliability , moderate validity , and a significant ability to predict functional capacity in patients with CHF who do not walk greater than 490 meters
PURPOSE To evaluate the reliability and validity of the six-minute walk test ( 6MWT ) with respect to its ability to predict functional capacity in patients with chronic heart failure .