SENIOR: Stroke Prevention in the Elderly by Patent Foramen Ovale closuRe vs Anticoagulation

Patent foramen ovale (PFO) is an important mechanism of embolic stroke of undetermined source (ESUS). Current guidelines recommend PFO closure for high-risk PFO in patients younger than 60 years, and a recent retrospective cohort study from Taichung Veterans General Hospital has shown that closure is effective and safe in older adults; however, the optimal treatment strategy for those \>60 years and direct head-to-head comparisons of PFO closure versus direct oral anticoagulants (DOACs) remain insufficient. Robust evidence from a multicenter study combining prospective and retrospective cohorts is warranted.

The SENIOR study is a multicenter observational cohort registry with a combined retrospective and prospective design. The prospective period is from September 15, 2025 to December 31, 2031, and the retrospective period covers January 1, 2013 to September 1, 2025; target sample sizes are 400 (prospective) and 500 (retrospective). We will enroll adults with ESUS and PFO; the prospective arm will focus on patients aged \>60 years with PFO related stroke. Treatments will be assigned as PFO closure, standard-dose DOAC, or antiplatelet agents (if DOAC intolerance) by local principal investigator. The primary outcome is recurrent ischemic stroke or transient ischemic attack. Secondary outcomes include 6-month functional outcome, all stroke, and serial comparison of atrial cardiopathy changes. Safety endpoints include peri-procedural adverse events (including newly-onset atrial fibrillation), hemorrhagic stroke, and all caused mortality. Clinical presentation, imaging, cardiac testing, biomarker, and genetic data will be collected for stratified and multivariable analyses.