Aims

Cognitive impairment (CI) in heart failure (HF) patients has mostly been studied in single countries in specific health care settings. Sociodemographic and clinical predictors of the global CI and CI dimensions are still unclear. We described CI in a diverse HF population recruited in several countries and in different health care settings and investigated sociodemographic and clinical factors associated with the global and specific CI dimensions in HF patients.

Methods and results

A secondary analysis from the baseline data of the Wii-HF trial. Patients (n = 605) were enrolled in Sweden, Italy, Israel, The Netherlands, Germany, and the United States. We used the Montreal Cognitive Assessment to evaluate CI and the 6 minute walk test (6MWT) to measure exercise capacity. Patients were on average 67 years old (SD, 12), and 86% were in New York Heart Association Class II and III. The mean Montreal Cognitive Assessment score was 24 (SD, 4), and 67% of patients had at least a mild CI. The item evaluating short-term memory had a considerable proportion of low scoring patients (28.1%). Worse CI was associated with patients' older age, lower education, and lower 6MWT scores (R² = 0.27). CI dimension scores were differently associated with specific clinical and demographic variables, but the 6MWT scores were associated with five out of seven CI dimension scores.

Conclusions

CI is an important problem in HF patients, with specific challenges in regard to memory. Exercise capacity is a modifiable factor that could be improved in HF patients with the potential to improve cognition and other outcomes in this population.

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.