Predictors of exercise capacity and everyday activity in older heart failure patients

Background: Exercise capacity and daily activity are key outcomes for older, frail heart failure patients. Little is known about the determinants of these outcomes in this patient group. Aims: To explore predictors of exercise capacity and daily activity in older, frail heart failure patients. Methods: Analysis of prospectively collected data from a cohort of 82 patients aged 70 years and over, enrolled in a randomised controlled trial of exercise in heart failure patients. Pathophysiological, demographic, psychological and social factors were analysed by multivariate regression to determine predictors of exercise capacity (6-min walk distance) and daily activity (daily accelerometer counts). Results: Between 49% and 55% of the variance in 6-min walk distance was explained by variables including New York Heart Association class, depression score, attitude to ageing and use of walking aids. Only 11% to 26% of the variance in accelerometer scores was explained by the model; 6-min walk distance was the only consistent predictor of daily activity. Conclusions: Physical, psychological and attitudinal variables contribute to variance of the 6-min walk. Six-minute walk distance predicts a small amount of the variance in daily activity, but the majority of variance in daily activity remains unexplained and requires further investigation.