Long-term risk of atrial fibrillation or flutter after transcatheter patent foramen ovale closure: a nationwide Danish study

Aims Transcatheter closure of patent foramen ovale (PFO) is the recommended stroke prevention treatment in patients <= 60 years with cryptogenic ischemic stroke and PFO. Atrial fibrillation or flutter (AF) is a known potential procedure-related complication, but long-term risk of developing AF remains unknown. This paper studied the long-term risk of developing AF following PFO closure. Methods and results A Danish nationwide cohort study was conducted. During 2008-2020, this study identified a PFO closure cohort, a PFO diagnosis cohort without PFO closure, and a general population comparison cohort matched 10:1 to the PFO closure cohort on age and sex. The outcome was first-time AF diagnosis. Risk of AF and multivariable-adjusted hazard ratio (HR) of the association between PFO closure or PFO diagnosis and AF were calculated. A total of 817 patients with PFO closure, 1224 with PFO diagnosis, and 8170 matched individuals were identified. The 5 year risk of AF was 7.8% [95% confidence interval (CI): 5.5-10] in the PFO closure cohort, 3.1% (95% CI: 2.0-4.2) in the PFO diagnosis cohort, and 1.2% (95% CI: 0.8-1.6) in the matched cohort. The HR of AF comparing PFO closure with PFO diagnosis was 2.3 (95% CI: 1.3-4.0) within the first 3 months and 0.7 (95% CI: 0.3-1.7) thereafter. The HR of AF comparing PFO closure with the matched cohort was 51 (95% CI: 21-125) within the first 3 months and 2.5 (95% CI: 1.2-5.0) thereafter. Conclusion Patent foramen ovale closure was not associated with any substantial increased long-term risk of developing AF beyond the well-known procedure-related short-term risk.