Background: Acute mesenteric ischemia (AMI) is associated with low survival rates. It is recommended to start early a full dose of anticoagulation therapy in patients with AMI, regardless of etiology, surgical or procedural perspective, or coagulation status. However, there are no international studies addressing the impact of timing and dose of anticoagulation therapy on outcome in AMI patients hospitalized in the intensive care unit (ICU). Methods: This international study combined data from 33 ICU centers in 19 countries. The primary outcome was 30-day survival. Secondary outcomes assessed duration of mechanical ventilation, ICU length of stay, occurrence of hemorrhagic complications and 90-day survival. We also identified independent risk factors for 30-day survival. Results: Among the 370 analyzed patients, 183 received early full-dose anticoagulation therapy and 187 did not. The 30-day survival was 53.5% (n = 98) in patients receiving early full-dose anticoagulation therapy and 41.7% (n = 78) in patients who did not (p = 0.01), with a number needed to treat (NNT) of n = 8. Early full-dose anticoagulation was associated with a longer duration of mechanical ventilation (p = 0.01). No differences were observed in ICU length of stay or hemorrhagic complications. Improved survival persisted in patients receiving early full-dose anticoagulation at 90 day (p = 0.02). We defined four multivariate Cox hazard models for 30-day survival. Only two intervention therapies were associated with survival: early full-dose anticoagulation and revascularization and/or bowel resection. Conclusion: This study suggests a significant survival benefit of early full-dose anticoagulation in ICU patients with acute mesenteric ischemia and no difference in hemorrhagic complications. Early full-dose anticoagulation and revascularization and/or bowel resection were associated with survival.
