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 = 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 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 & Innovation (UKRI)Medical Research Council UK (MRC) [FORSS 474681]