Aim: Atrial fibrillation (AF) is associated with an increased risk of stroke and high frequency of atrial ectopy (AE) is associated with an increased risk of AF. Extended ambulatory cardiac monitoring (EACM) is recommended to detect subclinical atrial fibrillation (AF) following a stroke episode. We aimed to compare the incidence of AF and the burden of AE detection in stroke and general cardiology patients referred for clinically relevant EACM.
Methods: A retrospective cohort study was completed in patients from stroke and cardiology clinics referred for continuous 28-day EACM (HeartBug Pty Ltd, Australia). AF and atrial ectopy (AE) was diagnosed by cardiac electrophysiologists.
Results: Stroke patients (n=9346) were older (median age 68 years) than the cardiology group (n=65578, 60 years, (p<0.001) and more likely to be male (57% vs 40%, p<0.001). AF was detected less frequently in stroke patients (4.66%) than cardiology patients (8.87%, OR 0.502 [0.454, 0.554], p<0.001). After adjustment for age, stroke remained independently associated with reduced rates of AF detection (aOR 0.420, [0.377, 0.468], p<0.001). AE burden was higher in stroke patients (90.15% vs 84.02%; aOR 1.110, [1.031, 1.195], p=0.006).
Conclusion: The rate of AF detection with EACM is lower in stroke patients, relative to those referred from cardiologists. Conversely, AE burden is increased in stroke, and this may better reflect the electrophysiologic phenotype associated with stroke than paroxysmal AF alone.