Lifestyle Walking Intervention in Patients With Heart Failure With Reduced Ejection Fraction: The WATCHFUL Trial.

Physical activity is pivotal in managing heart failure with reduced ejection fraction (HFrEF), and walking integrated into daily life is an especially suitable form of such physical activity. This study aimed to determine if a 6-month lifestyle walking intervention combining self-monitoring and regular phone counseling improves functional capacity assessed by the six-minute walk test (6MWT) in stable patients with HFrEF compared to usual care. The WATCHFUL trial was a 6-month, multicenter, parallel-group, randomized, controlled trial recruiting HFrEF patients from six Czech cardiovascular centers. Eligible participants were ≥18 years old with left ventricular ejection fraction <40% and NYHA class II/III symptoms, on guidelines-recommended medication, excluding those exceeding 450m in the baseline 6MWT. Patients in the intervention group were equipped with a Garmin vívofit activity tracker and received monthly phone counseling from research nurses who encouraged them to employ behavior change techniques such as self-monitoring, goal-setting, and action planning to increase their daily step count. The control group patients continued usual care. The primary outcome was the difference between groups in the distance (in meters) walked during the 6MWT at 6 months. Secondary outcomes included daily step count and minutes of moderate-to-vigorous physical activity (MVPA) as measured by the hip-worn Actigraph wGT3X-BT accelerometer, NT-proBNP and hsCRP biomarkers, ejection fraction, anthropometric measures, depression score, self-efficacy, quality of life, and survival risk score. The primary analysis was conducted by intention-to-treat. From 218 screened patients, 202 were randomized (65 years; 22.8% female; 90.6% NYHA II; left ventricular ejection fraction 32.5%; 6MWT 385m; 5071 steps/day; 10.9 minutes of MVPA per day). At six months, no between-group differences were detected for the 6MWT (7.4 m, 95% CI -8.0 to 22.7, p=0.345, N=186). The intervention group increased their average daily step count by 1420 (95% CI: 749; 2091) and daily minutes of MVPA by 8.2 (95% CI: 3.0; 13.3) over the control group. No between-group differences were detected for any other secondary outcomes. While the lifestyle intervention in patients with HFrEF improved daily steps by about 25%, it failed to demonstrate a corresponding improvement in functional capacity. Further research is needed to understand the disconnect between increased physical activity and functional outcomes.