Smartwatches for detection of atrial fibrillation (AFib) in secondary prevention of cryptogenic stroke - WATCH AFib

• Applicant: Dr. Silke Wunderlich
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology ; Cardiology, Angiology ; Public Health, Healthcare Research, Social and Occupational Medicine
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 460487359

Stroke is worldwide the second most frequent cause of death and disability and has a lifetime risk of approximately 25%. In the secondary prevention of ischemic stroke, detection of atrial fibrillation (AFib) and subsequent anticoagulation therapy reduce the risk of recurrent stroke by approx. 60%. Cryptogenic stroke is defined as ischemic stroke for which no probable cause is found despite a full standard evaluation and comprises 25% of all ischemic strokes. Prolonged heart rhythm monitoring for 30 days to 6 months significantly increases the detection of occult paroxysmal AFib in cryptogenic stroke, which is present in 9 – 16%. Thus, prolonged rhythm monitoring is likely to lead to a reduction of recurrent stroke by prompting adequate anticoagulation therapy. Still, prolonged AFib screening after stroke is currently suboptimal due to a limitation of resources, loss to follow-up, invasiveness of procedures, and costs. Wearables like smartwatches have recently been shown to adequately detect AFib in the general population. Compared to implantable event recorders, smartwatch based AFib diagnosis in the general population exhibits a sensitivity of 97.5% for AFib episodes >1h and a sensitivity of 100% for AFib detection per patient. As the implantation of one event recorder costs more than 3000 euro, smartwatches can also drastically reduce economic costs in our health systems. In conclusion, we hypothesize that AFib detection via smartwatch in patients suffering from cryptogenic transient ischemic attack or stroke is accurate compared to AFib detection via implantable event recorder and might therefore be a non-invasive, cost-effective, widely available alternative, which could potentially improve the current standard post-stroke treatment and lead to a reduction of further ischemic events, death and disability. To test our hypothesis we intend to compare sensitivity and specificity of AFib detection by continuously monitored and automatically analyzed heart rhythm via smartwatch with automated analysis via insertable event recorders. The trial is planned as a nation-wide, prospective, multicentric, single arm, observer blind, clinical study with an intraindividual control and will recruit 400 patients within 1.5 years. The choice of an intraindividual control does a) guarantee an accurate evaluation of sensitivity and specificity compared to a standard diagnostic device for detection of occult AFib (i.e. implantable event recorder), and b) ensures that all participants receive appropriate diagnostics and subsequent anticoagulation therapy if indicated. As the study intervention consists of additionally wearing a smartwatch, we consider the trial-associated risk for the individual participant as minimal, whereas the potential medical and economical benefit for the concerned population and health system is high.

• DFG Programme: Clinical Trials
• Co-Investigators: Dr. Eimo Martens; Dr. Horst Penkert