What is the clinical significance of AHRE?
The clinical significance of AHRE is presumed to be different from that of clinically identified AF since the latter, detected using conventional surface ECG methods, corresponds to a much higher AF burden as compared with patients with AHRE detected by continuous monitoring via a CIED. AHRE presence, duration, or burden of 5 minutes or 24 hours may modestly improve c-statistics of both the CHADS2 and CHA2DS2-VASc scores for predicting stroke. However, the actual rates of stroke or systemic embolic events reported in studies evaluating CIED-detected AHREs are often lower than what would be predicted by CHADS2 and CHA2DS2-VASc scores, and this may be related to concurrent treatment with OACs in each study, risk of under-reporting, and confounding. Furthermore, the temporal relationship between ischemic stroke and AF is less strict than expected, since stroke may occur without the concurrent presence of atrial tachyarrhythmias or AF at the time of stroke or in the days before. 