Factors associated with lack of improvement in submaximal exercise capacity of patients with heart failure

Aims Improvement in exercise capacity is the primary goal of physical activity programmes for patients with heart failure (HF). Although activity programmes are effective for some patients, others do not benefit. Identifying factors related to a lack of improvement in submaximal exercise capacity may help us interpret findings and design new interventions. The aim of this study is to identify factors contributing to a lack of improvement in submaximal exercise capacity 3 months after physical activity advice or an exergame intervention in patients with HF. Additionally, we aimed to assess differences in lack of improvement in submaximal exercise capacity of patients whose baseline exercise capacity predicted a worse compared with better prognosis of HF.Methods and results This secondary analysis of the HF-Wii study analysed baseline and 3 month data of the 6 min walk test (6MWT) from 480 patients (mean age 67 years, 72% male). Data were analysed separately in patients with a pre-defined 6 min walking distance at baseline of <300 m (n = 79) and >= 300 m (n = 401). Among patients with a baseline 6MWT of >= 300 m, 18% had deteriorated submaximal exercise capacity. In the multiple logistic regression analysis, lower baseline levels of self-reported physical activity [odds ratio (OR) = 0.77, 95% confidence interval (CI) = 0.60-0.97], lower baseline levels of cognitive function (OR = 0.87, 95%CI = 0.79-0.96) were significantly associated with lack of improvement in exercise capacity at 3 months. Not randomized to exergaming (OR = 0.63, 95%CI = 0.37-1.09) was likely (P = 0.097) to be associated with lack of improvement in exercise capacity at 3 months. Among the 79 patients with baseline 6MWT of <300 m, 41% (n = 32) did not improve 6MWT distance at 3 months. Independent predictors for the lack of improvement for 6MWT were New York Heart Association class III/IV (OR = 4.68, 95%CI = 1.08-20.35), higher levels of serum creatinine (OR = 1.02, 95%CI = 1.003-1.03), lower cognitive function (OR = 0.86, 95%CI = 0.75-0.99), and fewer anxiety symptoms (OR = 0.84, 95%CI = 0.72-0.98).Conclusions Lower self-reported physical activity and cognitive impairment predict lack of improvement in submaximal exercise capacity in HF patients. Patients who have a worse prognosis (score <300 m at the 6MWT) are often frail and gain less in exercise capacity. These patients may need a more comprehensive approach to have an effect on exercise capacity, including an individually tailored exercise programme with aerobic exercise (if tolerated) and strength exercises

Effects of exergaming on exercise capacity in patients with heart failure: results of an international multicentre randomized controlled trial

Aims Exergaming is a new tool to increase physical activity. This study aimed to determine the effects of access to a home-based exergame (Nintendo Wii) in patients with heart failure (HF) on exercise capacity, self-reported physical activity and patient-reported outcome measures.Methods and results We enrolled 605 HF patients in New York Heart Association functional class I-IV, independent of ejection fraction, in an international multicentre randomized controlled trial. Patients were randomized to exergame (intervention) or motivational support (control). The primary endpoint was change in submaximal aerobic exercise capacity as measured by the distance walked in 6 min (6MWT) between baseline and 3 months. Secondary endpoints included long-term submaximal aerobic exercise capacity, muscle function, self-reported physical activity, exercise motivation, exercise self-efficacy at 3, 6 and 12months. At baseline, patients on average walked 403142m on the 6MWT. Patients in the exergame group walked further compared to controls at 3 months (454123 vs. 420 +/- 127m, P = 0.005), at 6 months (452 +/- 123 vs. 426 +/- 133m, P = 0.015) and 12months (456 +/- 122 vs. 420 +/- 135m, P = 0.004). However, correcting for baseline 6MWT values by means of a linear mixed-effects model revealed no main effect for the intervention on 6MWT. Small significant effects on muscle function were found. Statistically significant treatment effects were found for muscle function but after correction for baseline and confounders, only the treatment effect for the heel-rise left at 6 months was significant (P<0.05). No treatment effect was found for exercise motivation, exercise self-efficacy, or self-reported physical activity.ConclusionExergaming was safe and feasible in patients with HF with different profiles in different health care systems, cultures and climates. However, it was not effective in improving outcomes on submaximal aerobic exercise capacity. Subgroup analysis did not identify specific subgroups benefiting from the intervention.Clinical Trial Registration: Identifier: NCT01785121

Physical activity in patients with heart failure: barriers and motivations with special focus on sex differences

Leonie Klompstra,1 Tiny Jaarsma,1 Anna Strömberg2,31Department of Social and Welfare Studies, Faculty of Health Sciences, 2Department of Medical and Health Sciences, Division of Nursing, 3Department of Cardiology, Linköping University, Linköping, SwedenBackground: Adherence to recommendations for physical activity is low in both male and female patients with heart failure (HF). Men are more physically active than women. In order to successfully promote physical activity, it is therefore essential to explore how much and why HF patients are physically active and if this is related to sex. The aim of this study was therefore to evaluate physical activity in HF patients, to describe the factors related to physical activity, and to examine potential barriers and motivations to physical activity with special focus on sex differences.Methods: The study had a cross-sectional survey design. HF patients living at home received a questionnaire during May–July 2014, with questions on physical activity (from the Short Form-International Physical Activity Questionnaire), and potential barriers and motivations to physical activity.Results: A total of 154 HF patients, 27% women, with a mean age of 70±10 were included. In total, 23% of the patients reported a high level of physical activity, 46% a moderate level, and 34% a low level. Higher education, self-efficacy, and motivation were significantly associated with a higher amount of physical activity. Symptoms or severity of the disease were not related to physical activity. All the potential barriers to exercise were reported to be of importance. Psychological motivations were most frequently rated as being the most important motivation (41%) to be physically active. Physical motivations (33%) and social motivations were rated as the least important ones (22%). Women had significantly higher total motivation to be physically active. These differences were found in social, physical, and psychological motivations.Discussion: One-third of the HF patients had a low level of physical activity in their daily life. Severity of the disease or symptoms were not related, whereas level of education, exercise self-efficacy, and motivation were important factors to take into account when advising a HF patient about physical activity. Women reported higher motivation to be physically active than men, but there was no difference in the reported level of physical activity.Keywords: barriers, sex differences, heart failure, motivation, physical activity, self-efficac

Letter: Response to letter to the editor: Seasonal variation in physical activity in patients with heart failure in HEART and LUNG, vol 49, issue 6, pp 576-576

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Seasonal variation in physical activity in patients with heart failure

Background and objectives: Physical activity is important for all heart failure (HF) patients to improve quality of life and physical function. Since adherence to physical activity is low and could differ between seasons, it is essential to explore factors related to change that may depend on seasonal changes. The purpose of this study was to describe the seasonal differences in physical activity and assess factors that influence these differences in a country with markedly different winter-to-summer weather conditions (in temperature, hours of daylight and snow fall). Methods: The study had a cross-sectional survey design. Outpatients with HF completed a questionnaire on physical activity, motivation and self-efficacy to exercise and I-IF symptom severity in the summer and the winter in a northern hemisphere country. We used analysis of variance to evaluate seasonal differences in physical activity, motivation, self-efficacy and HF symptom severity. Results: Eighty-seven patients with HF (29% women, mean age 70 +/- 9 years) were included and 35% performed less physical activity (METs) in the winter, compared to the summer. Increased symptom severity during the winter was associated with lower activity levels. Conclusion: One-third of the patients performed less physical activity during the winter compared to the summer, and this was associated with symptom severity. Decreased physical activity was not related with motivation and self-efficacy. This study emphasises the need for personalised physical activity programmes that also assess symptom severity and change in symptom severity depending between seasons. (C) 2019 The Authors. Published by Elsevier Inc.Funding Agencies|Swedish National Science Council [K2013 - 69X-22302-01-3, 2016-01390]; Swedish National Science Council/Swedish Research Council for Health, Working Life and Welfare [VR-FORTE 2014-4100]; Swedish Heart and Lung AssociationSwedish Heart-Lung Foundation [E085/12]; Swedish Heart-Lung FoundationSwedish Heart-Lung Foundation [20130340, 20160439]; VArdal Foundation [2014-0018]; Medical Research Council of Southeast Sweden [FORSS 474681]; Swedish Research Council for Health, Working Life and WelfareSwedish Research CouncilSwedish Research Council for Health Working Life &amp; Welfare (Forte) [FORTE 2017-02227]</p

Exercise Motivation and Self-Efficacy Vary Among Patients with Heart Failure - An Explorative Analysis Using Data from the HF-Wii Study

Purpose: To examine profiles in patients with heart failure (HF) regarding their exercise motivation and self-efficacy. Patients &amp; Methods: The baseline data of patients with HF participating in the HFWii study were analysed. In total, 517 patients were divided into four groups based on their exercise motivation (exercise motivation index) and self-efficacy (exercise self efficacy scale). To describe the differences in demographic and clinical variables between the groups, chi-square cross-tabulations and ANOVAs were conducted. Results: The four groups were labelled as insecure avoiders (25%), laid-back strugglers (10%), conscientious self-doubters (42%) and determined achievers (22%). Patients profiles differ according to their motivations and self-efficacy towards exercise. Most patients were conscientious self-doubters (high motivation and low self efficacy), and these patients had more comorbidities and lower exercise capacity compared to the other groups, which could decrease their confidence in exercising. However, only half of the patients who were determined achievers (high motivation and high self-efficacy) reached the recommended amount of physical activity per week. This indicates that motivation and self-efficacy are crucial determinants, but more factors are important for becoming more physically active. Conclusion: Understanding patients motivations and self-efficacy are necessary in order to provide meaningful physical activity counselling and promotion.Funding Agencies|Swedish National Science Council [K2013-69X-22302-01-3, 2016-01390]; Swedish National Science Council/the Swedish Research Council for Health, Working Life and Welfare, VR-FORTE [2014-4100]; Swedish Heart and Lung AssociationSwedish Heart-Lung Foundation [E085/12]; Swedish Heart and Lung FoundationSwedish Heart-Lung Foundation [20130340, 20160439]; Vardal Foundation [2014-0018]; Medical Research Council of Southeast SwedenUK Research &amp; Innovation (UKRI)Medical Research Council UK (MRC) [FORSS 474681]</p

Exploring factors related to non-adherence to exergaming in patients with chronic heart failure

Aims This study aimed to explore factors related to non-adherence to exergaming in patients with heart failure. Methods and results Data from patients in the exergame group in the HF-Wii trial were used. Adherence to exergaming was defined as playing 80% or more of the recommended time. Data on adherence and reasons for not exergaming at all were collected during phone calls after 2, 4, 8, and 12 weeks. Logistic regression was performed between patients who were adherent and patients who were non-adherent. Secondly, a logistic regression was performed between patients who not exergamed at all and patients who were adherent to exergaming. Finally, we analysed the reasons for not exergaming at all with manifest content analysis. Almost half of the patients were adherent to exergaming. Patients who were adherent had lower social motivation [odds ratio (OR) 0.072; 95% confidence interval (CI) 0.054-0.095], fewer sleeping problems (OR 0.84; 95% CI 0.76-0.092), and higher exercise capacity (OR 1.003; 95% CI 1.001-1.005) compared with patients who were non-adherent. Patients who not exergamed at all had lower cognition (OR 1.18; 95% CI 1.06-1.31) and more often suffered from peripheral vascular disease (OR 3.74; 95% CI 1.01-13.83) compared with patients who were adherent to exergaming. Patients most often cited disease-specific barriers as a reason for not exergaming at all. Conclusions A thorough baseline assessment of physical function and cognition is needed before beginning an exergame intervention. It is important to offer the possibility to exergame with others, to be able to adapt the intensity of physical activity.Funding Agencies|Swedish National Science Council [K2013-69X-22302-01-3, 2016-01390]; Swedish National Science Council/the Swedish Research Council for Health, Working Life and Welfare, VR-FORTE [2014-4100]; Swedish Heart and Lung Association [Hjart-Lungfonden] [E085/12]; Swedish Heart and Lung Foundation (Hjart-Lungfonden) [20130340, 20160439]; Vardal Foundation (Vardalstiftelsen) [2014-0018]; Medical Research Council of Southeast SwedenUK Research &amp; Innovation (UKRI)Medical Research Council UK (MRC) [FORSS 474681]</p

Isoforms of GPR35 have distinct extracellular N-termini that allosterically modify receptor-transducer coupling and mediate intracellular pathway bias

Within the intestine, the human G protein-coupled receptor (GPCR) GPR35 is involved in oncogenic signaling, bacterial infections, and inflammatory bowel disease. GPR35 is known to be expressed as two distinct isoforms that differ only in the length of their extracellular N-termini by 31 amino acids, but detailed insights into their functional differences are lacking. Through gene expression analysis in immune and gastrointestinal cells, we show that these isoforms emerge from distinct promoter usage and alternative splicing. Additionally, we employed optical assays in living cells to thoroughly profile both GPR35 isoforms for constitutive and ligand-induced activation and signaling of 10 different heterotrimeric G proteins, ligand-induced arrestin recruitment, and receptor internalization. Our results reveal that the extended N-terminus of the long isoform limits G protein activation yet elevates receptor-beta-arrestin interaction. To better understand the structural basis for this bias, we examined structural models of GPR35 and conducted experiments with mutants of both isoforms. We found that a proposed disulfide bridge between the N-terminus and extracellular loop 3, present in both isoforms, is crucial for constitutive G(13) activation, while an additional cysteine contributed by the extended N-terminus of the long GPR35 isoform limits the extent of agonist-induced receptor-beta-arrestin2 interaction. The pharmacological profiles and mechanistic insights of our study provide clues for the future design of isoform-specific GPR35 ligands that selectively modulate GPR35-transducer interactions and allow for mechanism-based therapies against, for example, inflammatory bowel disease or bacterial infections of the gastrointestinal system