Anticoagulants for the Prevention and Treatment of Venous Thromboembolism in Humans Exposed to Microgravity: A Systematic Review

Importance: Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), poses a significant risk to astronauts during long-duration space missions due to microgravity-induced physiological changes. Understanding the efficacy and safety of anticoagulants in space is essential for mitigating this risk.

Objective: To systematically review the literature on the efficacy and safety of pharmacological anticoagulation for the prevention and treatment of VTE in microgravity-exposed individuals.

Evidence Review: A systematic search was conducted following PRISMA guidelines across MEDLINE (via PubMed), Embase, Scopus, Web of Science, Cochrane Library, CINAHL, NASA Technical Reports Server, European Space Agency archives, ClinicalTrials.gov, NASA Life Sciences Data Archive, ESA Erasmus Experiment Archive, ISS Publications Archive, German Aerospace Center database, and NASA Space Station Research Database. The search included studies investigating pharmacological anticoagulation for VTE prevention or treatment in astronauts or individuals in spaceflight-like conditions. No date or language restrictions were applied. Study selection was based on predefined PICOS criteria. Screening was performed independently by one researcher.

Findings: No studies met the inclusion criteria, highlighting a significant gap in the literature. Despite extensive research on VTE risk and coagulation changes in microgravity, no published data directly evaluated the use of anticoagulants in this setting. This review explores the physiological impact of microgravity on coagulation, venous function, and VTE risk, emphasizing the need for validated space-specific risk assessment models and diagnostic tools. It also discusses potential pharmacologic and non-pharmacologic prevention strategies.

Conclusions and Relevance: The absence of evidence underscores an urgent need for research on anticoagulation strategies in space. Future studies should focus on evaluating anticoagulant efficacy and safety in microgravity, developing tailored risk assessment tools, and optimizing astronaut health protocols to mitigate VTE risk during space missions.