Effect of Dapagliflozin on Accelerometer-Based Measures of Physical Activity in Patients With Heart Failure: An Analysis of the DETERMINE Trials

BACKGROUND: Wearable accelerometers can quantify the frequency and intensity of physical activity during everyday life and may provide complementary data to established functional outcome measures on the effect of heart failure therapies on functional limitations. METHODS: In a voluntary substudy of the DETERMINE trials (Dapagliflozin Effect on Exercise Capacity Using a 6-Minute Walk Test in Patients With Heart Failure), patients wore a waist-worn triaxial accelerometer for as long as possible (ideally for 24 h/d for 7 days) at 3 points during the trial, between the screening visit and randomization (baseline data), and during weeks 8 and 14 to 16. Accelerometer outcomes included the change from baseline to week 16 in the total number of steps, time spent in light-to-vigorous physical activity, time spent in moderate-to-vigorous physical activity, movement intensity during walking, number of vector magnitude units‚ and total activity counts. RESULTS: Adequate baseline and week 16 accelerometer data were available for 211 of 817 (26%) randomized patients (defined as ≥10 hours of wear time for ≥3 days). Dapagliflozin had a favorable effect on the mean change from baseline at 16 weeks in the number of steps (between-group difference, 778 [95% CI, 240–1315]), time spent in moderate-to-vigorous physical activity (0.16 [95% CI, 0.03–0.29] hours), and in the mean vector magnitude units (25 [95% CI, 0.1–49] counts per minute). There were no between-group differences in the other accelerometer outcomes of interest. CONCLUSIONS: In this exploratory analysis of the DETERMINE trials, dapagliflozin had a beneficial effect on selected accelerometer-based measures of physical activity in patients with heart failure across the entire left ventricular ejection fraction spectrum, yet did not improve 6-minute walk distance, as previously reported. These data suggest that accelerometer-based measurements of everyday activity may provide complementary information to 6-minute walk distance and identify beneficial effects of treatment not detected by 6-minute walk distance.