Exercise training and testing in patients with heart failure

Patients with heart failure (HF) suffer from symptoms such as dyspnea, fatigue and reduced quality of life, which affect their physical function and often lead to immobilization and poor survival prognosis. Exercise training in cardiac rehabilitation should be offered to every patient with HF and can be performed both in a hospital-setting and with a home training programme. Exercise, in patients with HF, improves physical function and functional capacity as well as health-related quality of life (HRQoL) and reduces the need for hospital care. There are several barriers against participating in exercise based cardiac rehabilitation despite information about its benefits. The patient may anticipate not being able to exercise, that the exercise would be too hard, lives far away or has not been referred. Aim: The aim of this thesis was to evaluate the effects of exercise in heart failure patients, of a one-year training programme, with hospital-based training followed by a home-based setting or only home-based, with special emphasis on peripheral muscle training (PMT). Furthermore, to study frequently used methods for evaluation of the effects, i.e the 6-minute walk test and instruments for estimating health-related quality of life. Methods and findings: In study I, PMT was evaluated and the PMT programme in a hospital-setting (with equipment) and subsequent homebased training (with elastic bands) was compared with solely home-based training, over 1 year. At follow-up every third month, duplicated six minute walk test (6MWT) and two HRQoL questionnaires were used. The walking distance increased significantly after three months in both groups and was maintained thereafter. Also HRQoL increased but at different time points. In study II, PMT was compared with interval training on an ergometer bike/free walking. Both groups started under supervision of a physiotherapist in a hospital-setting, for three months and thereafter at home for nine months. The same measurements were used as in study I. Neither walking distance nor HRQoL changed over the study period. However, this may be regarded as a positive effect in the light of the known progressive nature of heart failure. In study III, the 6MWTs from study I and II were used to evaluate the necessity of performing duplicated 6MWTs in follow-ups clinically and for research purposes. We found that it is sufficient to perform one 6MWT. In study IV, both 6MWT and HRQoL forms from study I and II were used to investigate the relationship between walking distance and perceived HRQoL in HF patients. Patients with shorter walking distance, than the group median, experienced poorer general HRQoL but not HRQoL related to HF, than the higher performing half of the study group. There were no longitudinal trends in these relationships. Conclusion: PMT can be used as an exercise modality in patients with HF, both in hospital and at home, and may be evaluated with a single 6MWT. Shorter walking distance was related to a lower general HRQoL as judged by the patients but there was no significant relation between short walking distance and the HF-related HRQoL. Individualizing the training programme and methods, and offering the choice of exercise modality and the possibility of exercising at home, might be a way to increase adherence in cardiac rehabilitation. Patienter med hjärtsvikt besväras av andfåddhet och trötthet vilket påverkar deras fysiska funktion och ofta leder till immobilisering, nedsatt livskvalitet och dålig prognos. Träning inom hjärtrehabilitering bör erbjudas alla patienter med hjärtsvikt och kan utföras såväl på sjukhus som hemma med hemträningsprogram. Träning vid hjärtsvikt förbättrar fysisk funktion och funktionell kapacitet, hälsorelaterad livskvalitet, och minskar behovet av vård på sjukhus. Det finns många barriärer till att delta i hjärtrehabilitering trots information om vinster, t ex att patienten tror sig inte klara av att träna, bor långt ifrån, har inte fått remiss för att nämna några.  Syfte: Syftet med avhandlingen var att utvärdera effekterna av ett träningsprogram för patienter med hjärtsvikt under 1 år, träning på sjukhus följt av hemträning eller enbart hemträning. Ett specifikt syfte var att utvärdera perifer muskelträning (PMT) som en möjlig, lämplig träningsmetod för hjärtsviktspatienter. Vidare var syftet att utvärdera effekten av sex minuters gångtest och hälsorelaterad livskvalitet.  Metod och resultat: I studie I utvärderades PMT och jämförde träning på sjukhus (med redskap) med efterföljande hemträning (med elastiska band) med enbart hemträning under 1 år. Vid utvärdering var tredje månad användes dubbla sex minuters gångtest och frågeformulär om livskvalitet. Gångsträckan ökade signifikant efter träning och höll i sig hela träningsperioden i båda grupperna. Även livskvaliteten ökade men vid olika tidpunkter. I studie II, jämfördes PMT med intervallträning på ergometercykel/promenader. Båda grupperna tränade under ledning av fysioterapeut i tre månader och därefter hemma upp till 1 år. Samma utvärdering som i studie I. Gångsträcka och livskvaliteten ändrade sig inte under studietiden. Det kan dock ses som en positiv effekt eftersom hjärtsviktspatienter vanligen försämras över tid. I studie III, användes gångtesten från studie I och II för att utvärdera om det är nödvändighet att utföra dubbla sex minuters gångtest vid utvärdering. Ingen kliniskt betydelsefull skillnad sågs mellan gångtest ett och två. I studie IV, användes både gångtest och livskvalitetsformulär, från studie I och II, för att undersöka samband mellan gångsträcka och upplevd livskvalitet och om detta samband ändrades med tiden. Patienter med kortare gångsträcka upplevde sämre allmän hälsorelaterad livskvalitet men inte livskvalitet relaterad till hjärtsvikten, någon kliniskt signifikant förändring över tid kunde inte påvisas.  Konklusion: Perifer muskelträning kan användas som en säker träningsform för patienter med hjärtsvikt, både på sjukhus och som hemträning och kan utvärderas med endast ett sex minuters gångtest. Patienter med kortare gångsträcka upplever sämre allmän livskvalitet vilket förefaller relativt oberoende av de olika testtidpunkterna.Funding agency: Region Kalmar County and the Research section.</p

Test-retest reliability of six-minute walk tests over a one-year period in patients with chronic heart failure

Purpose The aims of this study were to determine the test-retest reliability of the duplicated six-minute walk test (6MWT) in patients with chronic heart failure (HF), and to evaluate its variation over time. Methods Forty-six patients (9 women) with HF performed duplicated 6MWT every third month for 1 year (5 follow-ups), for a total of 198 paired tests. The patients completed two 6MWT on the same day with a 45-min seated rest between tests. Results The mean distance in metres, for the first (6MWT1) versus the second (6MWT2), for each follow-up, was 408 +/- 100 versus 411 +/- 96, 449 +/- 94 versus 465 +/- 94, 464 +/- 96 versus 473 +/- 100, 462 +/- 103 versus 468 +/- 104 and 472 +/- 105 versus 482 +/- 107. On average, a marginally, clinically insignificant longer walked distance, 9 m (2.0%), was seen in the second 6MWT. The standard error of a single determination (S-method) ranged from 2.4% to 3.9% over the study period, and the intraclass correlation coefficient (ICC) ranged from 0.96 to 0.99 (CI 95% 0.94-0.99). The variation over time of ICC or S-method was not statistically significant. Conclusion The 6MWT is highly reliable over time in patients with HF, and one test is, therefore, sufficient in clinical follow-ups.Funding Agencies|Research Committee, Kalmar County Council, Sweden; Department of Physiotherapy, Region Kalmar County, Sweden</p

The relationship between six-minute walked distance and health-related quality of life in patients with chronic heart failure

Objectives. To assess the relationship between the six-minute walk test (6MWT) and health-related quality of life (HRQL) in patients with chronic heart failure. Methods. Forty-six patients (37 men and 9 women) with chronic heart failure, mean age 68 (SD 9), NYHA II-III and EF 29 (9) % were included. They performed 6MWT and assessed HRQL using two tools, a Swedish version of the 36-item Short Form (SF-36) and the Minnesota Living with Heart Failure Questionnaire (MLHFQ). This was performed repeatedly during a study period of one year. Results. Patients with a walking distance lower than median experienced a lower HRQL than the higher performing half of the cohort, in four dimensions of the SF-36 and the summary of physical and mental components, but not in the dimensions of MLHFQ. Conclusion. Patients with heart failure with a short walking distance assessed their quality of life as inferior in half of the dimensions in the SF-36 but not in the dimensions measured with the MLHFQ. Thus, different aspects of the symptomatology are uncovered using the 6MWT and the different HRQL tools

Comparison of the 6-minute walk distance measured on a 30 m track with guidance of a healthcare professional and those measured with a mobile application outdoors by participants themselves : a validation study

To improve the practical application of measuring exercise capacity, the purpose of this study was to compare the 6 min walk distance (6MWD) obtained at a 30 m track with the guidance of healthcare professionals vs. the 6MWD obtained by participants themselves using an app. In total, 37 participants performed both tests. The mean of the differences between the 6MWD on the tests was -4 +/- 45 m (95% limits of agreement: 84 to -99 m). The overall agreement between the two 6MWD measures was 97% with an intraclass correlation coefficient of 0.96 (95% confidence interval: 0.91-0.98, P &amp;lt; 0.001). The use of an app is feasible, reliable, and valid to assess the 6MWD.Funding Agencies|Swedish Research Council for Medicine and Health-VR [2018-02719]; Swedish Research Council for Health, Working Life and Welfare-FORTE [2018-00650]; Swedish Heart-Lung Foundation [20170766]; FORSS [941180]</p