Study protocol for The Heart Watch Study - Prognostic performance of smartwatch 12-lead ECG with advanced ECG analysis in consumer self-screening for cardiovascular disease

Background It is now possible to acquire a fully diagnostic standard 12-lead electrocardiography (ECG) using a smartwatch, a smartphone app, and no additional hardware. This study aims to evaluate the predictive performance of advanced ECG (A-ECG) analysis applied to a smartwatch 12-lead ECG (SWECG) acquired using an Apple Watch in identifying cardiovascular risks among asymptomatic adults performing consumer self-screening in the general population. Methods and Design The Heart Watch Study is a prospective, Australia-wide observational cohort study. The study will recruit 30,000 participants aged 20-79 years without prior known cardiovascular disease. Participants will enrol and consent electronically, and download a dedicated study iPhone app that enables a directed 12-lead SWECG acquisition using an Apple Watch. The recordings will undergo both conventional and A-ECG analysis. Follow-up will be performed through linkage with administrative health datasets in Australia, including hospital visits and mortality. The primary combined endpoint is all-cause mortality, hospitalization for cardiovascular causes, and incident cardiovascular disease (arrythmia, ischemic heart disease, heart failure) as predicted by existing A-ECG analyses. Conclusion This study evaluates the feasibility of performing a fully diagnostic standard 12-lead SWECG using only a smartwatch and a smartphone application, and addresses the prognostic value of A-ECG machine-learning based analysis in consumer self-screening in a large, diverse and apparently healthy population.