Long-term Outcomes After Percutaneous Patent Foramen Ovale Closure (Severance PFO Registry)

Patent foramen ovale (PFO) is a congenital interatrial communication present in about one quarter of the general population and is recognized as a major cause of cryptogenic stroke. Percutaneous PFO closure reduces recurrent stroke, but a residual right-to-left shunt persists in 20 to 40 percent of patients after device implantation. Long-term data on device performance, the evolution of residual shunt over time, new-onset atrial fibrillation and other prognostic factors remain limited. This single-center registry evaluates the long-term efficacy and safety of percutaneous PFO closure and identifies the clinical, anatomical, procedural and pharmacological factors associated with clinical and echocardiographic outcomes. The registry combines a retrospective cohort of patients treated at Severance Hospital between 2010 and March 2026 with a prospective registry extension that enrolls patients undergoing PFO closure after institutional review board approval, with follow-up for up to 119 months. Clinical outcomes include recurrent ischemic stroke or transient ischemic attack, all-cause death, device-related complications and new-onset atrial fibrillation. Echocardiographic outcomes are assessed by serial agitated saline transthoracic echocardiography, which allows the presence, grade and longitudinal trajectory of residual shunt to be characterized.