Percutaneous closure of an interatrial shunt significantly improves oxygenation and symptoms in patients with platypnea-orthodeoxia syndrome (POS), with a low procedural complication rate. A systematic review of 196 studies involving 469 patients (mean age 68.3 years; 51% female) characterized the clinical features, anatomical contributors, and outcomes of percutaneous closure of a patent foramen ovale (PFO) or atrial septal defect (ASD). The most common presentation was orthodeoxia, or a drop in oxygen saturation when upright (95%), followed by exertional dyspnea (42%) and platypnea, or breathlessness when upright (35%). The median time from symptom onset to diagnosis was 13 weeks. Common anatomical contributors included aortic dilation (33%), thoracic structural abnormalities or prior surgery (33%), and right heart disorders (15%). Following shunt closure, mean oxygen saturation increased substantially from 79.5% to 94.5%, and symptomatic improvement was reported in 82% of cases, while procedural complications occurred in only 5%. These findings highlight that POS remains underdiagnosed and should be considered in patients with positional oxygen desaturation and otherwise unexplained hypoxemia. Percutaneous shunt closure offers substantial physiological and symptomatic benefits with a favorable safety profile. Source: https://heart.bmj.com/
