Physical Activity in Adults With Wearable Cardioverter Defibrillators in the Post–Myocardial Infarction Period

Abstract

Purpose: Wearable cardioverter defibrillators (WCDs) provide lifesaving defibrillation and are equipped with accelerometers, capable of providing information on patient wear time and physical activity (PA). The purpose of this study was to report on patient PA while wearing a WCD. Methods: This study derived data from the WCD vendor in patients prescribed WCD post–myocardial infarction (MI) with left ventricular ejection fraction ≤35% in 2016. Using the device accelerometer, the relationship between wear time and PA was examined in a sample of consistent wearers of the WCD. Demographic variables, including sex and age, were examined for impact on wear time and PA. Changes in PA over time were also examined. Results: A total of 1952 patients (71% male) with a median age of 63 yr were included. Descriptive analyses indicated that overall median wear time was 23.8 hr/d; PA was 5568 steps/d. Significant differences in PA over time were identified, with median steps increasing by 67% from the first week of wear to the last week of wear. Patient age and wear time significantly predicted PA; patient age also significantly predicted patient wear time. There were significant differences in median hours of wear time, as well as median steps, based on sex. Conclusions: PA in adults early after hospital discharge is modest and improves over the course of the 90-d WCD prescription in regular wearers. Improved health status may account for this change. The WCD accelerometer may have value in future clinical care and research by providing a window into daily patient PA levels via remote monitoring.

Collaborative care for the wearable cardioverter defibrillator patient: Getting the patient and medical team “vested and active”

“…prescribed WCD post-acute MI in 2016, suggested that patients had significantly increased step counts over 13 weeks of WCD use (e.g.,~90 days). 21 Step counts increased from 3739 during the first week of wear to 6230 during last week of wear, representing a 67% increase in physical activity over a 90-day WCD prescription. Further analysis of the data suggested female patients wore the WCD significantly more time, but men completed significantly more steps (difference of 829/day).…”

“…Additionally, older patients wore the device more time, but younger patients were more active. 21 Increases in patient age strongly predicted increases in device wear-time and decreases in physical activity after 40 years of age. 21 This study was SEARS ET AL.…”

“…Examination of patient activity via device accelerometer represents another potential data point for risk stratification in patients with WCD (Table 2). 20,21 The WCD accelerometer has established utility as a reliable tool for home-based 6MWT. 22 In the TRENDS study, comparisons of home-based versus clinic-based 6MWT for 197 patients, indicated that patients who were compliant with the frequency of their homebased prescription had no statistically significant difference between the results of home-based versus clinic-based 6MWT.…”

“…Examination of patient activity via device accelerometer represents another potential data point for risk stratification in patients with WCD (Table 2). 20,21 …”

“…provides a step-by-step guide to patient education for clinicians to consider. Existing research further highlights that there are individual differences in wear time and activity 21. Women are more likely to wear the device for longer periods.…”