"Arterial EMBOLism After Catheter Ablation of Atrial Fibrillation (EMBOL AF)"

BACKGROUND

Arterial embolisms, particularly brain embolism (stroke or TIA) is one of the most clinically relevant complications of AFAbl procedures. According to the 2017 HRS/EHRA/ECAS/APHRS/SOLAECE consensus the incidence is reported to be very variable (0-7%) and the high-risk period extends for the first two weeks following ablation . A strict management of uninterrupted oral anticoagulation and an intraprocedural activated clotting time (ACT) target >300 s along with careful use of imaging techniques to rule out interatrial thrombus and high-flow perfusion of sheaths placed in the heart are necessary measures to reduce the incidence of this complication. However, the real incidence of periprocedural stroke / TIA remains high, as exemplified by the results of the CABANA trial where 26 out of 1.006 (2.58%) patients in the ablation group (who actually underwent ablation) had stroke or TIA. More recently, the incidence of stroke when extensive ablation in the LA in addition to the PVI ablation has been 1.5% in the DECAAF trial, 0.4% in the STABLE-SR II trial and 0% in the ERASE-AF trial. The Spanish Catheter Ablation Registry has reported an incidence of stroke of 0.2% in 2020 and 2021, but these numbers may be underestimated due to the voluntary self-reported data collection of this registry. In another population-based registry the incidence of stroke among octogenarian patients after AFAbl was 0.6%.

Although the relevance of this complication is well established in terms of incidence and clinical impact, two critical aspects remain insufficiently investigated. Firstly, little is known about the acute clinical characteristics, therapeutic management and sequelae of stroke or TIA after AFABl. Secondly, the occurrence of stroke/TIA might be more frequent with certain ablation techniques. The widespread use of newer ablation techniques in the last years, such as different modalities of cryoablation, laser ablation and pulsed-field ablation, may influence the incidence or severity of embolic events. In consequence, a large international registry is justified to further clarify these less known aspects.

The EMBOL-AF is a multicenter, international, observational study designed as a retrospective registry that will investigate the characteristics of systemic arterial embolic events after treatment of atrial fibrillation by catheter ablation. Due to the retrospective nature of the study, the registry is specially focused on cerebral embolism (stroke and TIA) because these are not only the most frequent and clinically relevant but also the most susceptible to underreporting. However, all embolism associated to AFAbl will be included.

This study will gather all clinically relevant aspects and data of all cases of arterial embolism that have occurred over the last 5 years in the centers that will participate in the registry. Based on these reported cases, the incidence, management and outcomes of embolic events (particularly stroke and TIA) will be studied.