Phenotypic Characterization of People at Risk of Atrial Fibrillation: Protocol for the FIND-AF Longitudinal Cohort Study

Aims The Future Innovations in Novel Detection of Atrial Fibrillation (FIND-AF) longitudinal cohort study is a multi-centre prospective cohort study of patients identified at risk of atrial fibrillation (AF). The aim of the FIND-AF longitudinal cohort study is to provide multi-modal phenotypic characterization of these patients.Methods and results A total of 1955 participants identified as at risk of AF by the FIND-AF algorithm from primary care electronic health record (EHR) data, aged 30 years and above and eligible for oral anticoagulation, will be recruited between October 2023 and November 2024 to receive home-based intermittent electrocardiogram monitoring. About 500 participants without diagnosed AF will then undergo cross-sectional phenotypic characterization including physical examination, symptoms assessment, serum blood biomarkers and echocardiography, and non-stress cardiac magnetic resonance imaging. Longitudinal information about cardio-renal-metabolic-pulmonary outcomes will be ascertained from linkages to EHR data. The study is funded by the British Heart Foundation (CC/22/250026). The study has ethical approval (North West-Greater Manchester South Research Ethics Committee reference 23/NW/0180). Findings will be announced at relevant conferences and published in peer-reviewed journals in line with the funder's open-access policy.Conclusion The FIND-AF multi-centre prospective longitudinal cohort study aims to (i) provide evidence for the impact of comorbidities on AF genesis, (ii) uncover actionable targets to prevent AF, and (iii) act as a platform for cohort randomized clinical trials that investigate enhanced detection and prevention of AF. Atrial fibrillation (AF) is the most common abnormal heart rhythm encountered in clinical practice, but we know little about changes to the heart before AF starts and whether these can be reversed to reduce the risk of future AF. In this study, we will recruit people who have been identified as higher risk of AF using a decision support tool in their medical records but who have not been found to have AF at the moment when they have had their electrocardiogram checked. We will look at the structure and function of their hearts using ultrasound and magnetic resonance imaging, and we will also check their blood tests. We aim to learn if people without AF, but at higher risk of AF, have changes to their heart and then conduct studies to establish if these changes can be reversed. Graphical Abstract