ECG-patch assessment of atrial fibrillation during the very-early blanking predicts late blanking period recurrence: preliminary data from a prospective registry

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Ablation of atrial fibrillation (AF) is a procedure that causes significant atrial tissue lesions, with transient, albeit significant tissue oedema and inflammation. These mechanisms may trigger early rhythm abnormalities that do not necessarily correlate with future arrhythmias, and, therefore, evaluation of AF recurrence is currently validated by routine ECG and ambulatory 24h Holter monitoring, only after a 3-month blanking period. However, recent data have shown that AF episodes occurring during the blanking period are common and may predict late AF recurrences. The E-Patch (Bio Tel Heart) is an innovative, thin single-use adhesive electrode with extended continuous ECG monitoring for up to 120h. AIM: To assess if continuous extended monitoring in the very-early blanking period can be associated with event recorder data performed in the late blanking period after AF ablation. METHODS: Single-centre, prospective, longitudinal study, including consecutive patients (P) 24h after AF ablation, monitored with the E-patch. The effectiveness of the device in continuously recording within 5 days after ablation was analyzed, as well as the occurrence of AF episodes during an external 7- day loop-recorder, obtained in the 2nd-month post-ablation. RESULTS: A total of 30P were included (57% male, 63±8 years). AF ablation was performed with radiofrequency (RF) energy in 14P and with a balloon of cryoenergy in 16P. All P were in sinus rhythm at the beginning of the recording. The mean number of hours of recording was 113±16, with no discomfort complaints in the use of the device or interpretation artefacts. During the E-patch monitoring, a total of 10P (33%) presented AF (AF burden 6.8% of the recording, IQR 3.0-20%). All 30P underwent an external loop recorder for 7 days 2 months post-ablation, with 40% showing AF periods (> 30 seconds duration). All 10P that had AF detection in the very-early E-patch recording had also recurrence in the 2 nd month of extended 7-day continuous recording. Very- early AF detection had a sensitivity of 83.3% and a specificity of 100% to detect late blanking period AF (ROC 0.916±0.06; 95%CI 080-1.0). CONCLUSIONS: The use of the E-patch very-early after AF ablation is effective for AF detection and is highly predictive of AF recurrence in the late blanking period. These findings require validation in larger studies to assess the potential of very-early assessment in the determination of a higher risk for AF recurrence.