Wearable Physical Activity Monitoring in Patients with Coronary Artery Disease: Feasibility, Validity and Clinical Utility

Background:
Patients with symptomatic coronary artery disease (CAD) frequently experience
limitations in daily activities and quality of life. While medication is the first line
treatment for angina, percutaneous coronary intervention (PCI) also relieves
symptoms in obstructive CAD. Treatment success is evaluated through patient
reported outcomes, lacking objective assessment methods.
Objective:
To explore alternative methods for assessing patient response to coronary
revascularisation in stable angina using prolonged physical activity monitoring.
Methods:
The Virtu-5 study recruited 37 symptomatic CAD patients, using wrist-worn activity
trackers. Patients underwent fractional flow reserve (FFR) guided PCI and were
monitored continuously before and after their procedure. Activity data were collected
for three months pre-procedure and for three to six months post-procedure.
Additionally, questionnaires and six-minute walk tests (6MWT) were conducted at
baseline and follow-up.
Results:
Twenty-five patients underwent PCI, whilst twelve patients with FFR negative
disease continued medical management. Compliance with activity tracker usage was
high, and device step counting accuracy was confirmed against manual counting.
Patients with FFR positive disease achieved higher daily moderate to vigorous
physical activity levels versus patients who were found to have FFR negative
disease. The PCI group did not demonstrate an improvement in objective physical
activity behaviours between baseline and follow up. Questionnaire responses and
6MWT outcomes were shown to be superior in the FFR positive group. Several
variables were found to be significantly correlated with changes in physical activity
behaviours, including demographic, wearer compliance and atmospheric factors.
Despite low prior experience with activity trackers, user experience was positive.
Conclusion:
The findings from this work suggest that prolonged physical activity monitoring with
wrist-worn activity trackers is a feasible method of collecting data from patients with
CAD. Wearable technology-based monitoring may provide valuable and objective
information for clinicians and researchers to assess the impact of CAD and
revascularisation in patients with angina.