Stroke and systemic embolism are known complications of atrial fibrillation (AF) and atrial flutter (AFL) ablation, but their incidence and procedural associations are not well defined. Published in European Heart Journal, this retrospective global registry initiated by the European Heart Rhythm Association (EHRA) Scientific Committee analyzed embolic events following AF and left AFL ablation between 2017 and 2024.

Data were collected from 204 centers reporting 335,743 ablation procedures, along with detailed records of symptomatic embolic events. A total of 550 events were identified, corresponding to an incidence of 0.16%, with center-level rates ranging from 0% to 3.1%. Most events were cerebral (94%), followed by peripheral (5%) and combined events (1%).

Coronary air embolism accounted for 62% of peripheral events. In terms of timing, 17% of events occurred during the procedure, 78% within 72 hours, and 22% beyond 72 hours, with 23% identified after hospital discharge.

Higher embolic event rates were associated with nonparoxysmal AF compared with paroxysmal AF (0.23% vs 0.15%; P<0.001). Event rates also varied by ablation modality, including radiofrequency (0.16%), cryoballoon (0.16%), pulsed field ablation (0.25%), and laserballoon (0.88%) (P<0.001), as well as by center experience.

The median National Institutes of Health Stroke Scale (NIHSS) score was 4 (interquartile range, 2-9). At 3 months, follow-up data were available for 95% of patients, with 35% experiencing sequelae and 3% mortality.

Symptomatic embolic events were uncommon but associated with measurable morbidity and mortality. Most events occurred early, although a proportion developed later, with higher rates observed with laser ablation and possibly with pulsed field ablation.