Frailty, Physical Activity, and Mobility in Patients With Cardiac Implantable Electrical Devices

Background: This study aimed to demonstrate the feasibility of measuring frailty in patients with cardiac implantable electrical devices while validating the physiologic significance of device-detected physical activity by evaluating its association with frailty and mobility. Methods and Results: Outpatients with cardiac implantable electrical devices compatible with physical activity analysis with at least 7 days of data were eligible. Office testing included frailty status (Study of Osteoporotic Fractures instrument), gait speed (m/s), mobility according to the Timed Up and Go (TUG) test (seconds), and daily physical activity (h/d) as measured by cardiac implantable electrical device. Among 219 patients, Study of Osteoporotic Fractures testing found 39.7% to be robust, 47.5% prefrail, and 12.8% frail. The mean gait speed for the cohort was 0.8 +/- 0.3 m/s, mean TUG time was 10.9 +/- 4.4 seconds, and mean activity was 2.8 +/- 1.9 h/d. Frail patients were markedly more likely to have gait speeds < 0.8 m/s (OR 6.25, 95% CI 1.79-33.3). In unadjusted analyses each 1-hour increase in mean daily activity was associated with a 46% reduction of frail phenotype (OR 0.54, 95% CI 0.40-0.74) versus robust and with a 27% reduction in the odds of having the prefrail phenotype (OR 0.73, 95% CI 0.62-0.86). After adjustment this association per hour of activity persisted, with an adjusted OR for frailty of 0.71 (95% CI 0.51-0.99) and adjusted OR for prefrailty of 0.81 (95% CI 0.67-0.99). Conclusions: Frailty and mobility limitation are common among cardiac implantable electrical device patients and are correlated to device-detected physical activity.