Diagnosis and Treatment of Patent Foramen Ovale-associated Cryptogenic Stroke.

Patent foramen ovale (PFO) is an important cause of cryptogenic stroke (CS), and its pathogenic mechanisms involve paradoxical embolism, in situ thrombus, hemodynamic changes caused by atrial remodeling, and high-risk anatomical features such as atrial septal aneurysm. Clinical assessment requires multidisciplinary evaluation of anatomical high-risk features, stroke imaging characteristics, and Risk of Paradoxical Embolism (RoPE) score to determine treatment plans. Currently, interventional closure and oral antithrombotic therapy are recommended, but the determination of interventional indications and the choice between anticoagulants and antiplatelet drugs remain controversial. From the perspective of pathological mechanisms, patients with PFO-related CS may have venous emboli caused by right-to-left shunting, and anticoagulant therapy can more precisely intervene in the chain reaction of embolism by inhibiting venous thrombus formation and promoting the dissolution of in situ thrombi. Based on the PICO principle, this review summarizes currently published studies on PFO, including clinical trials, guideline statements, and position papers. It summarizes the diagnosis and treatment of PFO and proposes mechanism-based hypotheses for validation in future large-scale clinical studies.