Correlates of objectively measured physical activity in cardiac patients

Negative Attitudes, Self-efficacy, and Relapse Management Mediate Long-Term Adherence to Exercise in Patients With Heart Failure

BACKGROUND

Exercise is safe and provides considerable benefits for patients with heart failure (HF) including improved function, quality of life, and symptoms. However, patients with HF have difficulty initiating and adhering to an exercise regimen. To improve adherence, our team developed Heart Failure Exercise and Resistance Training (HEART) Camp, a multicomponent, theory-driven intervention that was efficacious in a randomized controlled trial of long-term adherence to exercise in patients with HF. Identifying active components of efficacious interventions is a priority.

PURPOSE

The purpose of this study is to use mediation analysis to determine which interventional components accounted for long-term adherence to exercise in patients with HF.

METHODS

This study included 204 patients with HF enrolled in a randomized controlled trial. Instruments measuring interventional components were completed at baseline, 6, 12, and 18 months. Hierarchical linear models generated slope estimates to be used as predictors in logistic regression models. Significant variables were tested for indirect effects using path analyses with 1,000 bootstrapped estimates.

RESULTS

Significant mediation effects were observed for the interventional components of negative attitudes (β NA = 0.368, s.e. = 0.062, p < .001), self-efficacy (β SE = 0.190, s.e. = 0.047, p < .001), and relapse management (β RM = 0.243, s.e. = 0.076, p = .001).

CONCLUSIONS

These findings highlight improving attitudes, self-efficacy, and managing relapse as key interventional components to improve long-term adherence to exercise in patients with HF. Future interventions targeting adherence to exercise in patients with HF and other chronic illnesses should consider the incorporation of these active components.

Accelerometer-Measured Daily Activity Levels and Related Factors in Patients With Heart Failure

BACKGROUND

Few studies report objective accelerometer-measured daily physical activity levels in patients with heart failure (HF).

OBJECTIVE

We examined baseline accelerometer-measured physical activity from the Heart Failure Exercise and Resistance Training Camp trial, a federally funded (R01-HL112979) 18-month intervention study to promote adherence to exercise in patients with HF. Factors associated with physical activity levels were also explored.

METHODS

Patients with diagnosed HF (stage C chronic HF confirmed by echocardiography and clinical evaluation) were recruited from 2 urban medical centers. Physical activity energy expenditure and the number of minutes of moderate or vigorous physical activity (MVPA) were obtained from 7 full days of measurement with the accelerometer (Actigraph Model GT3X, Pensacola, Florida) for 182 subjects who met minimum valid wear time parameters. Additional measures of health-related factors were included to explore the association with physical activity levels.

RESULTS

Subjects had 10.2 ± 10.5 minutes of MVPA per day. Total physical activity energy expenditure was 304 ± 173 kcal on average per day. There were 23 individuals (12.6%) who met the recommended goal of 150 minutes of MVPA per week. Men, whites, New York Heart Association class II, and subjects with better physical function had significantly higher levels of activity.

CONCLUSIONS

Consistent with previous research, patients with HF are not meeting recommended guidelines for 150 minutes of MVPA per week.