Resistance training improves vasoreactivity in end-stage heart failure patients on inotropic support. Superior Cardiovascular Effect of Aerobic Interval Training Versus Moderate Continuous Training in Heart Failure Patients: A Randomized Study Value of Peak Exercise Oxygen Consumption for Optimal Timing of Cardiac Transplantation in Ambulatory Patients With Heart Failure Benefits of physical training on exercise capacity, inspiratory muscle function, and quality of life in patients with ventricular assist devices long-term postimplantation Exercise Anaerobic Threshold and Ventilatory Efficiency Identify Heart Failure Patients for High Risk of Early Death Interval versus continuous training in lung transplant candidates: a randomized trial. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials Reduced Functional Measure of Cardiovascular Reserve Predicts Admission to Critical Care Unit following Kidney Transplantation The minimal important difference of exercise tests in severe COPD Prognostic Implications of Preoperative Aerobic Capacity and Exercise Oscillatory Ventilation After Liver Transplantation Effects of exercise training on exercise capacity and quality of life in patients with a left ventricular assist device: a preliminary randomized controlled trial. Submaximal cardiopulmonary exercise testing predicts 90-day survival after liver transplantation. Exercise, education, and quality of life in lung transplant candidates. Pulmonary rehabilitation in patients referred for lung transplantation. Baseline 6‐Min Walk Distance Predicts Survival in Lung Transplant Candidates Six-minute walk distance predicts mortality in liver transplant candidates.
PURPOSE Peripheral vascular abnormalities contribute to compromised functional status in heart failure ( HF ) patients . The purpose of the present study was to test whether the intervention of moderate-intensity , resistance training could improve peripheral vascular responsiveness , that is , flow-mediated dilation ( FMD ) in HF . METHODS Baseline brachial artery FMD analysis ( 2 minutes of cuff occlusion and 5 minutes of reperfusion ) was measured in HF patients on intravenous inotropic support ( n = 9 ) awaiting cardiac transplantation .  Unilateral , upper-body resistance exercises ( moderate intensity , combination of isometric and isotonic exercises at 60%-80 % of maximum ) were performed 3 d/wk for 4 weeks . Follow-up FMD analysis was conducted after training . Central hemodynamics were defined via right-side-heart catheterization . RESULTS At baseline prior to training , HF patients elicited a significant hyperemic response 10 seconds following cuff occlusion ( mean increase in blood flow : 194 ± 44 mL/min , P < .05 ) . Despite this significant hyperemic response , HF patients demonstrated a mild , but paradoxical vasoconstriction of nearly 3 % at 1-minute after cuff release . Four weeks of resistance training corrected the paradoxical vasoconstriction observed at baseline and result ed in vasodilatation ( a positive increase in brachial artery diameter of 0.04 ± 0.04 mm , at 1 minute after cuff release ; P < .05 ) . Conversely , in a subset of 3 HF patients , studies in the untrained contralateral arm revealed no change in the FMD response . CONCLUSION Moderate-intensity upper-body resistance training  improved brachial artery FMD in end-stage HF patients on inotropic support . The reversal of the paradoxical vasoconstrictive response to reactive hyperemia following 4 weeks of training may be secondary to local improvements in vascular endothelial function rather than a quantitative change in the reactive hyperemic stimulus Background — Exercise training reduces the symptoms of chronic heart failure . Which exercise intensity yields maximal beneficial adaptations is controversial . Furthermore , the incidence of chronic heart failure increases with advanced age ; it has been reported that 88 % and 49 % of patients with a first diagnosis of chronic heart failure are > 65 and > 80 years old , respectively . Despite this , most previous studies have excluded patients with an age > 70 years . Our objective was to compare training programs with moderate versus high exercise intensity with regard to variables associated with cardiovascular function and prognosis in patients with postinfa rct ion heart failure . Methods and Results — Twenty-seven patients with stable postinfa rct ion heart failure who were undergoing optimal medical treatment , including & bgr;-blockers and angiotensin-converting enzyme inhibitors ( aged 75.5±11.1 years ; left ventricular [ LV ] ejection fraction 29 % ; & OV0312;o2peak 13 mL · kg−1 · min−1 ) were r and omized to either moderate continuous training ( 70 % of highest measured heart rate , ie , peak heart rate ) or aerobic interval training ( 95 % of peak heart rate ) 3 times per week for 12 weeks or to a control group that received st and ard advice regarding physical activity . & OV0312;o2peak increased more with aerobic interval training than moderate continuous training ( 46 % versus 14 % , P<0.001 ) and was associated with reverse LV remodeling . LV end-diastolic and end-systolic volumes declined with aerobic interval training only , by 18 % and 25 % , respectively ; LV ejection fraction increased 35 % , and pro-brain natriuretic peptide decreased 40 % . Improvement in brachial artery flow-mediated dilation ( endothelial function ) was greater with aerobic interval training , and mitochondrial function in lateral vastus muscle increased with aerobic interval training only . The MacNew global score for quality of life in cardiovascular disease increased in both exercise groups . No changes occurred in the control group . Conclusions — Exercise intensity was an important factor for reversing LV remodeling and improving aerobic capacity , endothelial function , and quality of life in patients with postinfa rct ion heart failure . These findings may have important implication s for exercise training in rehabilitation programs and future studies Background Optimal timing of cardiac transplantation in ambulatory patients with severe left ventricular dysfunction is often difficult . To determine whether measurement of peak oxygen consumption ( Vo2 ) during maximal exercise testing can be used to identify patients in whom transplantation can be safely deferred , we prospect ively performed exercise testing on all ambulatory patients referred for transplant between October 1986 and December 1989 . Methods and Results Patients were assigned into one of three groups on the basis of exercise data : Group 1 ( n = 35 ) comprised patients accepted for transplant ( Vo2<14 ml/kg/min ) ; group 2 ( n = 52 ) comprised patients considered too well for transplant ( Vo2 > 14 ml/kg/min ) ; and group 3 ( n = 27 ) comprised patients with low Vo2 rejected for transplant due to noncardiac problems . All three groups were comparable in New York Heart Association functional class , ejection fraction , and cardiac index ( p = NS ) . Pulmonary capillary wedge pressure was significantly lower in group 2 than in either group 1 or 3 ( p<0.05 ) , although there was wide overlap . Patients with preserved exercise capacity ( group 2 ) had cumulative 1- and 2-year survival rates of 94 % and 84 % , which are equal to survival levels after transplantation . In contrast , patients rejected for transplant ( group 3 ) had survival rates of only 47 % at 1 year and 32 % at 2 years , whereas patients awaiting transplantation ( group 1 ) had a survival rate of 790 % at 1 year ( both ( p < 0.005 versus patients with Vo2 > 14 ml/kg/min ) . All deaths in group 2 were sudden . By univariate and multivariate analyses , peak Vo2 was the best predictor of survival , with only pulmonary capillary wedge pressure providing additional prognostic information . Conclusions .These data suggest that cardiac transplantation can be safely deferred in ambulatory patients with severe left ventricular dysfunction and peak exercise Vo2 of more than 14 ml/min/kg . ( Circulation 1991;83:778–786 Background : Capacity to exercise may not be fully restored in patients with heart failure even in the long term after ventricular assist device ( VAD ) implantation . The benefits of exercise training in patients with VAD are unknown . Design and methods : Fifteen patients , aged 38.3 ± 15.9 years , bridged to heart transplantation with left ventricular assist device or biventricular assist device were r and omized at a ratio of 2 : 1 to a  training group  ( TG , n = 10 ) or a control group ( n = 5 ) , 6.3 ± 4 months after implantation . Both the groups were advised to walk 30–45 min/day . TG also underwent moderate-intensity aerobic exercise using a bike or treadmill for 45 min , three to five times a week , combined with high-intensity inspiratory muscle training using a computer- design ed software to respiratory exhaustion , two to three times a week for 10 weeks . The patients were tested using cardiopulmonary exercise testing , 6-min walk test , spirometry and electronic pressure manometer for inspiratory muscle strength ( Pimax ) and endurance ( sustained Pimax ) measurement . Quality of life was assessed with the Minnesota Living with Heart Failure question naire . Results : TG improved peak oxygen consumption ( 19.3 ± 4.5 vs. 16.8 ± 3.7 ml/kg per min , P = 0.008 ) and VO2 at ventilatory threshold ( 15.1 ± 4.2 vs. 12 ± 5.6 ml/kg per min , P = 0.01 ) , whereas the ventilation/carbon dioxide slope decreased ( 35.9 ± 5.6 vs. 40 ± 6.5 , P = 0.009 ) . The 6-min walk test distance increased ( 527 ± 76 vs. 462 ± 88 m , P = 0.005 ) and quality of life was improved ( 38.2 ± 11.6 vs. 48.9 ± 12.8 , P = 0.005 ) , as well as Pimax ( 131.8 ± 33 vs. 95.5 ± 28cmH2O , P = 0.005 ) , sustained Pimax ( 484 ± 195 vs. 340 ± 193cmH2O/s/10 3 , P = 0.005 ) , and inspiratoty lung capacity ( 2.4 ± 0.9 vs. 1.7 ± 0.7 L , P = 0.008 ) were improved . No significant changes were noted in the control group . Conclusion : Our findings indicate that exercise training may improve the functional status of VAD recipients  even at a later period after implantation and thus , may have additional importance in cases of destination therapy Background —The  maximal oxygen uptake ( peak & OV0312;o2 ) is used in risk stratification of patients with chronic heart failure ( CHF ) .  Peak & OV0312;o2 might be lower than maximally possible if exercise is stopped early because of lack of patient motivation or premature cessation by the investigator . In contrast , the anaerobic threshold ( & OV0312;o2AT ) and the ventilatory efficiency ( & OV0312;e versus & OV0312;co2 slope ) are less subject to these influences . Thus , we compared these parameters with peak & OV0312;o2 in identifying patients with CHF at increased risk for death within 6 months after evaluation . Methods and Results —We performed cardiopulmonary exercise tests with gas exchange measurements in 223 consecutive patients with CHF ( 114 coronary artery disease , 92 dilated cardiomyopathy , 17 others ) at the Herzzentrum Ludwigshafen between 1995 and 1998 . We measured peak & OV0312;o2 , & OV0312;o2AT and & OV0312;e versus & OV0312;co2 slope . We selected peak & OV0312;o2 of ≤14 mL/kg per minute , & OV0312;o2AT of < 11 mL/kg per minute , and & OV0312;e versus & OV0312;co2 slope of > 34 as threshold values for high risk of death . The median follow-up time was 644 days . Patients with peak & OV0312;o2 of ≤14 mL/kg per minute had a > 3-fold-increased risk ( OR=3.4 ; CI , 1.3 to 9.1 ) , with & OV0312;o2AT < 11 mL/min per kg or & OV0312;e versus & OV0312;co2 slope > 34 a 5-fold increased risk for early death ( OR=5.3 ; CI , 1.5 to 19.0 ; OR=4.8 ; CI , 1.7 to 13.8 , respectively ) . In patients with both & OV0312;o2AT < 11 mL/kg per minute and & OV0312;e versus & OV0312;co2 slope > 34 , the risk of early death was 10-fold higher ( OR=9.6 ; CI , 2.1 to 44.7 ) . After correction for age , sex , left ventricular ejection fraction , and New York Heart Association class in a multivariate analysis , the combination of & OV0312;o2AT < 11 mL/kg per minute and & OV0312;e versus & OV0312;co2 slope > 34 was the best predictor of 6-month mortality ( RR=5.1 , P = 0.001 ) . Conclusions —&OV0312;o2AT of < 11 mL/kg per minute and slope of & OV0312;e versus & OV0312;co2 > 34 , combined , better identified patients at high risk for early death from CHF than did peak & OV0312;o2 and should therefore be considered when prioritizing patients for heart transplantation BACKGROUND Interval ( IT ) and continuous training ( CT ) represent well-established exercise modalities in patients with moderate to severe chronic obstructive pulmonary disease ( COPD ) . However , their effects and feasibility in patients with end-stage COPD remain unclear . METHODS Sixty patients ( 53 ± 6 years , 53 % women ) being evaluated for lung transplantation where r and omly assigned either to IT ( n = 30 , cycling at 100 % peak work rate for 30 seconds alternating with 30 seconds of rest ) or CT ( n = 30 , cycling at 60 % of peak work rate ) during a 3-week inpatient rehabilitation program . Both exercise protocol s yielded an equivalent amount of total work . Patients had a mean forced expiratory volume at 1 second ( FEV(1 ) ) of 25 % ± 8 % of predicted value . RESULTS Patients in both groups achieved similar clinical ly relevant improvements in 6-minute walking distance of 35 ± 29 meters for IT and 36 ± 43 meters for CT , with a between-group difference of 0.3 meters ( 95 % confidence interval , -18.2 to 18.8 ) . Changes in lung function parameters were not significant . Perceived intensity of dyspnea was significantly ( p < 0.05 ) lower in IT ( Borg 6.2 ± 1.8 ) compared with CT ( Borg 7.1 ± 1.7 ) . Patients required a median of 5 unintended breaks ( interquartile range , 2 - 28 ) during IT exercise and 29 ( interquartile range , 6 - 68 ) during CT ( p < 0.001 ) . CONCLUSIONS IT is associated with a lower intensity of dyspnea during exercise and fewer unintended breaks but achieves similar improvements in exercise capacity compared with CT in pre-lung transplant COPD patients Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Background There is currently no effective preoperative assessment for patients undergoing kidney transplantation that is able to identify those at high perioperative risk requiring admission to critical care unit ( CCU ) . We sought to determine if functional measures of cardiovascular reserve , in particular the anaerobic threshold ( VO2AT ) could identify these patients . Methods Adult patients were assessed within 4 weeks prior to kidney transplantation in a University hospital with a 37-bed CCU , between April 2010 and June 2012 .  Cardiopulmonary exercise testing ( CPET ) , echocardiography and arterial applanation tonometry  were performed . Results There were 70 participants ( age 41.7±14.5 years , 60 % male , 91.4 % living donor kidney recipients , 23.4 % were desensitized ) . 14 patients ( 20 % ) required escalation of care from the ward to CCU following transplantation . Reduced anaerobic threshold ( VO2AT ) was the most significant predictor , independently ( OR = 0.43 ; 95 % CI 0.27–0.68 ; p<0.001 ) and in the multivariate logistic regression analysis ( adjusted OR = 0.26 ; 95 % CI 0.12–0.59 ; p = 0.001 ) . The area under the receiver-operating-characteristic curve was 0.93 , based on a risk prediction model that incorporated VO2AT , body mass index and desensitization status . Neither echocardiographic nor measures of aortic compliance were significantly associated with CCU admission . Conclusions To our knowledge , this is the first prospect i ve observational study to demonstrate the usefulness of CPET as a preoperative risk stratification tool for patients undergoing kidney transplantation . The study suggests that VO2AT has the potential to predict perioperative morbidity in kidney transplant recipients Our aim was to determine the minimal important difference ( MID ) for 6-min walk distance ( 6MWD ) and maximal cycle exercise capacity ( MCEC ) in patients with severe chronic obstructive pulmonary disease ( COPD ) . 1,218 patients enrolled in the National Emphysema Treatment Trial completed exercise tests before and after 4–6 weeks of pre-trial rehabilitation  , and 6 months after r and omisation to surgery or medical care .  The St George 's Respiratory Question naire ( domain and total scores ) and University of California San Diego Shortness  of Breath Question naire ( total score ) served as anchors for anchor-based MID estimates . In order to calculate distribution-based estimates , we used the st and ard error of measurement , Cohen 's effect size and the empirical rule effect size . Anchor-based estimates for the 6MWD were 18.9 m ( 95 % CI 18.1–20.1 m ) , 24.2 m ( 95 % CI 23.4–25.4 m ) , 24.6 m ( 95 % CI 23.4–25.7 m ) and 26.4 m ( 95 % CI 25.4–27.4 m ) , which were similar to distribution-based MID estimates of 25.7 , 26.8 and 30.6 m. For MCEC , anchor-based estimates for the MID were 2.2 W ( 95 % CI 2.0–2.4 W ) , 3.2 W ( 95 % CI 3.0–3.4 W ) , 3.2 W ( 95 % CI 3.0–3.4 W ) and 3.3 W ( 95 % CI 3.0–3.5 W ) , while distribution-based estimates were 5.3 and 5.5 W. We suggest a MID of 26±2 m for 6MWD and 4±1 W for MCEC for patients with severe COPD Our aim was to determine preoperative aerobic capacity ( oxygen uptake [ V′O2 ] ) and prevalence of  exercise oscillatory ventilation ( EOV ) , underlying clinical characteristics of patients with EOV  , and significance of reduced aerobic capacity and EOV in predicting mortality after liver transplantation . We prospect ively studied 263 patients who underwent elective liver transplantation .  Patients were followed up for 1 year . Despite minor impairment of resting cardiopulmonary function , preoperative aerobic capacity was reduced ( peak V′O2 : 64 ± 19 % predicted ) . EOV occurred in 10 % of patients . Model for End‐Stage Liver Disease score tended to be higher in patients with EOV compared to patients without , but failed to reach significance ( p = 0.09 ) . EOV patients had lower peak V′O2 and higher ventilatory drive . EOV was more frequent in nonsurvivors than in survivors ( 30 % vs. 9 % , p = 0.01 ) and was independently associated with posttransplant all‐cause 1‐year mortality . Reduced peak V′O2 best predicted the primary composite endpoint defined as 1‐year mortality and /or prolonged hospitalization and early in‐hospital mortality . Multivariate analysis  revealed EOV ( χ2 , 3.96 ; p = 0.04 ) and V′O2 ( χ2 , 4.28 ; p = 0.04 ) as independent predictors of mortality and so‐called primary composite endpoint , respectively  . EOV  and reduced peak V′O2 may identify high‐risk c and i date s for liver transplantation , which would motivate a more aggressive treatment when detected BACKGROUND A paucity of studies has examined the effect of exercise training  after left ventricular assist device ( LVAD ) implantation . Previous research has demonstrated that insertion of the LVAD alone improves exercise capacity and quality of life ( QOL ) . This study investigated whether supervised exercise training results in a further improvement . METHODS This prospect i ve , r and omized controlled trial with concealed allocation , assessor blinding , and intention-to-treat analysis investigated the effect of exercise training on exercise capacity and QOL in 14 patients who underwent LVAD insertion as a bridge to heart transplantation .  Exercise training consisted of 8 weeks of gym-based aerobic and strengthening exercises 3 times a week , with a progressive mobilization program , compared with the control group that completed mobilization alone .  Exercise capacity was measured before and after the intervention using maximal cardiopulmonary exercise testing and 6-minute walk distance ( 6MWD ) . QOL was measured using the Short Form 36-item assessment . RESULTS No adverse events were reported . There was a trend toward greater improvement in peak oxygen consumption ( Vo(2 ) ) , 6MWD , and QOL in the exercise group ( n = 7 ) compared with the control group ( n = 7 ) ; however , no significant between-group difference was detected for improvements in peak Vo(2 ) [ mean difference ( exercise -- control ) ] of 2.96 ml/kg/min ( 95 % confidence interval , -1.04 to 6.97 ) , 6MWD at 54 meters ( -51 to 159 meters ) , and QOL scores over time ( p > 0.05 ) . CONCLUSION Exercise training is feasible and safe in patients with a LVAD . Trends toward greater improvement in exercise capacity and QOL after exercise training warrant further investigation in a larger trial Liver transplantation has a significant early postoperative mortality rate . An accurate preoperative assessment is essential for minimizing mortality and optimizing limited donor organ re sources . This study assessed the feasibility of preoperative submaximal cardiopulmonary exercise testing ( CPET ) for determining the cardiopulmonary reserve in patients being assessed for liver transplantation and its potential for predicting 90-day posttransplant survival .  One hundred eighty-two patients underwent CPET as part of their preoperative assessment for elective liver transplantation . The 90-day mortality rate , critical care length of stay , and hospital length of stay were determined during the prospect i ve posttransplant follow-up . One hundred sixty-five of the 182 patients ( 91 % ) successfully completed  CPET ; this was defined as the ability to determine a submaximal exercise parameter : the anaerobic threshold ( AT ) . Sixty of the 182 patients ( 33 % ) underwent liver transplantation , and the mortality rate was 10.0 % ( 6/60 ) . The mean AT value was significantly higher for survivors versus nonsurvivors ( 12.0 ± 2.4 versus 8.4 ± 1.3 mL/minute/kg , P < 0.001 ) . Logistic regression revealed that AT , donor age , blood transfusions , and fresh frozen plasma transfusions were significant univariate predictors of outcomes . In a multivariate analysis , only AT was retained as a significant predictor of mortality . A receiver operating characteristic curve analysis demonstrated sensitivity and specificity of 90.7 % and 83.3 % , respectively , with good model accuracy ( area under the receiver operating characteristic curve = 0.92 , 95 % confidence interval = 0.82 - 0.97 , P = 0.001 ) . The optimal AT level for survival was defined to be > 9.0 mL/minute/kg . The predictive value was improved when the ideal weight was substituted for the actual body weight of a patient with refractory ascites , even after a correction for the donor 's age . In conclusion , the preoperative cardiorespiratory reserve ( as defined by CPET ) is a sensitive and specific predictor of early survival after liver transplantation . The predictive value of CPET requires further evaluation In addition to improved functional ability , patients who complete rehabilitation programs typically have positive psychologic changes , including increased motivation and an enhanced quality of life . Potentially , patients with end-stage lung disease awaiting a lung transplant can have similar benefits . However , no studies were identified that examined the impact of an exercise program on quality of life in patients awaiting lung transplantation . This pilot study was an initial step toward evaluating outcomes of a health maintenance program on exercise tolerance and quality of life .  Subjects were nine lung transplant c and i date s who met lung transplant listing criteria and who were r and omized to participate in a 6-week health maintenance program consisting of education alone or education plus exercise .  Subjects completed cardiopulmonary exercise testing , a 6-minute walk , and the Quality of Well-being scale , Quality of Life Index , and Symptom Frequency/Symptom Distress scale before and after completion of the program . No significant between-group changes were seen . Quality of Well-being scores ( p < 0.005 ) and 6-minute walk distance ( p < 0.03 ) improved over time in both groups . Findings suggest that patients awaiting lung transplantation perceived improved quality of well-being and increased walk distance after participation in a health maintenance program . Education plus exercise conferred no benefits beyond those achieved by education alone . However , the number of subjects studied was small and duration of follow-up was limited Effectiveness of pulmonary rehabilitation in patients with chronic obstructive lung diseases , cystic fibrosis , and interstitial lung disease is well documented but little is known about the results of pulmonary rehabilitation in patients referred for lung transplantation . The purpose of this study is to prospect ively examine the efficacy of Nordic walking , a low cost , accessible , and proven beneficial form of physical exercise , as a form of pulmonary rehabilitation in patients referred for lung transplantation . Twenty-two male patients referred for lung transplantation at the Department of Lung Diseases and Tuberculosis in Zabrze , Pol and , were invited to take part in the study . The rehabilitation program , which was conducted for 12 weeks , was based on Nordic walking exercise training with ski poles .  Lung function tests ( FVC , FEV1 ) , mobility ( 6 min walking test ( 6MWT ) ) , rating of dyspnea ( Oxygen Cost Index , MRC and Baseline Dyspnea Index ) , and quality of life assessment s ( SF-36 ) were performed before and after the completion of the exercise program . No adverse events were observed after completing the pulmonary rehabilitation program in patients referred for lung transplantation . After 12 weeks of pulmonary rehabilitation with Nordic walking we observed a significant increase in the mean distance walked in the 6MWT ( 310.2 m vs. 372.1 m , p < 0.05 ) . The results of lung function tests also showed improvement in FVC . There were no significant differences in the perception of dyspnea before and after completing the rehabilitation program . General health and quality of life question naire ( SF-36 ) showed improvement in the domain of social functioning ( p < 0.05 ) . In conclusion , pulmonary rehabilitation with a Nordic walking program is a safe and feasible physical activity in end-stage lung disease patients referred for lung transplantation and results in improvements in patients ' mobility and quality of life In a large , prospect ively followed , two‐center cohort of patients listed for lung transplantation ( n = 376 ) , we used Cox proportional hazards models to determine the importance of baseline 6‐min walk distance ( 6MWD ) in predicting patient survival . 6MWD used as a continuous variable was a significant predictor of survival after adjusting for other important covariates when transplant was considered as a time‐varying covariate ( HR for each 500 ft increase in 6MWD = 0.57 , 95 % CI : 0.43–0.77 , p = 0.0002 ) . 6MWD remained an important predictor of survival in models that considered only survival to transplant ( HR for each 500 ft increase in 6MWD = 0.41 , 95 % CI : 0.27–0.62 , p < 0.0001 ) or survival only after transplant ( HR for each 500 ft increase in 6MWD = 0.40 , 95 % CI : 0.22–0.72 , p = 0.002 ) . Unadjusted Kaplan‐Meier analysis demonstrates significantly different survival by 6MWD tertiles ( < 900 , 900–1200 , or > 1200 ft , p‐value = 0.0001 ) . In the overall model , 6MWD prediction of survival was relatively homogeneous across disease category ( 6MWD by disease interaction term , p‐value = 0.63 ) . Our results demonstrate a significant relationship between baseline 6MWD and survival among patients listed for lung transplantation that exists across all native disease categories and extends through transplantation . The 6MWD is thus a useful measure of both urgency and utility among patients awaiting lung transplantation The 6-minute walk distance ( 6MWD ) is a simple test measuring global physical function . It is commonly used to predict mortality in patients with cardiac and pulmonary diseases , but it is also useful in assessing the functional status of patients with a variety of other medical conditions . We sought to determine ( 1 ) the characteristics of the 6MWD in patients listed for liver transplantation ( LT ) , ( 2 ) the existence of a relationship between the 6MWD and the quality of life , and ( 3 ) the relationship between the 6MWD and survival in LT c and i date s. The 6MWD was prospect ively measured in all patients listed for LT . The 6MWD was determined when the listed Model for End-Stage Liver Disease ( MELD ) score was ≥ 15 . Patients were followed until LT , death , removal from the wait list , or the end of the study period . Quality of life was assessed with the Short Form 36 ( SF-36 ) . In 121 patients , the mean 6MWD was 369 ± 122 m ; it was not related to age , height , weight , body mass index , albumin level , or etiology of liver disease and showed a moderate correlation with the physical component score ( PCS ) on the SF-36 ( r = 0.4 ) and a moderate inverse correlation with the native MELD score ( r = -0.61 ) . In an unadjusted analysis , a high native MELD score , a low 6MWD , and a low PCS were associated with mortality , with only the 6MWD retaining significance after adjustment for covariates . Each 100-m increase in the 6MWD was significantly associated with increased survival ( hazard ratio = 0.48 , P = 0.0001 ) , with 6MWD < 250 m being associated with an increased risk of death ( P = 0.0001 ) . In conclusion , the 6MWD is significantly reduced in patients awaiting LT and is inversely correlated with the native MELD score . A pretransplant 6MWD < 250 m is a risk for death on the wait list
BACKGROUND Patients awaiting solid-organ transplantation may be encouraged to undertake exercise training to improve pre- and post-transplant outcomes .
However , the safety , adherence and efficacy of exercise training in this population remain unclear .