4-year ischaemic stroke risk higher after patent foramen ovale closure

Patients with patent foramen ovale (PFO) closure have a greater risk of ischaemic stroke at 4 years than those in the general population, according to a study.

Nationwide population-based Danish registries were used in this cohort study, which involved patients with PFO closure from 2008 to 2021 (n=1,162) and a birth year- and sex-matched comparison cohort from the general population (n=11,620).

The investigators calculated the absolute and relative risks of ischaemic stroke within 4 years after PFO closure. They also estimated the adjusted hazard ratios (HRs) of the association between PFO closure vs the general population and ischaemic stroke using weighted Cox regression.

The absolute risks of ischaemic stroke in patients with PFO closure were 1.4 percent (95 percent confidence interval [CI], 0.8–2.3) at 1 year, 1.4 percent (95 percent CI, 0.8–2.3) at 2 years, 2.2 percent (95 percent CI, 1.3–3.5) at 3 years, and 2.5 percent (95 percent CI, 1.5–4.0) at 4 years.

The absolute risks in the general population were much lower at 0.1 percent (95 percent CI, 0.0–0.1), 0.2 percent (95 percent CI, 0.2–0.4), 0.4 percent (95 percent CI, 0.2–0.5), and 0.4 percent (95 percent CI, 0.3–0.6) at 1, 2, 3, and 4 years, respectively.

Overall, the absolute 4-year risk of ischaemic stroke was higher by 2.1 percent (95 percent CI, 0.9–3.3) in patients with PFO closure than in the general population, with an adjusted hazard ratio of 6.3 (95 percent CI, 3.1–12.6).