NASA Working Group Recommends No Change to Astronaut PFO Selection, Calls for Risk‑Mitigation Protocols

NASA’s latest working‑group report on decompression sickness (DCS) and venous thromboembolism (VTE) for Artemis missions has clarified how patent foramen ovale (PFO) status should be handled. The panel, which reviewed recent data and updated standards, concluded that a small PFO (grade 1‑2) does not increase DCS risk and that PFO presence is not a major VTE risk factor. Consequently, NASA will not alter astronaut selection criteria for PFOs. However, crews that undergo PFO screening will be fully informed of their status and offered closure for large PFOs (grade 3+), while protocols will be adjusted to mitigate risk. The group also called for clear clinical guidance on pre‑EVA aspirin use and on analgesics that could mask DCS symptoms. These measures aim to keep astronauts safe during lunar surface operations.