[Severe gastrointestinal bleeding in patients with atrial fibrillation receiving oral anticoagulants (based on REGistry of long-term AnTithrombotic TherApy - REGATTA)].

Background: The rate of major bleeding in patients with atrial fibrillation receiving oral anticoagulants is 25% per year. Gastrointestinal bleedings are at least a half of major hemorrhagic complications. Currently, there is no optimal scale to calculate the risk of bleeding, and therefore the search for clinical predictors of gastrointestinal bleeding remains relevant.

Aim: To assess the frequency and structure of large gastrointestinal bleeding, as well as to identify clinical predictors of their development based on long-term prospective observation of patients with atrial fibrillation receiving oral anticoagulants.

Materials And Methods: Data were obtained from single center prospective REGistry of long-term AnTithrombotic TherApy (REGATTA NCT043447187). Investigation based on a 20-year follow-up with 510 patients with atrial fibrillation with a high thromboembolic risk (median CHA2DS2-VASc was 4 points). The REGATTA registry assessed the frequency and structure of major gastrointestinal bleeding. Predictors of the development of 32 large gastrointestinal bleeding were identified based on the analysis of pairs with univariate and multivariate analyses.

Results: The frequency of major gastrointestinal bleeding in patients with atrial fibrillation receiving oral anticoagulants at 1 year was 1.42 per 100 patients; the predominant localization was upper gastrointestinal tract. Predictors of the development of major gastrointestinal bleeding according to multiple regression data analysis were hemoglobin level 14.55 g/dL, body mass index 28.4 kg/m2, gastrointestinal ulcer or erosive lesion and major hemorrhagic complications in history of disease. In 1/2 cases the sourse of bleeding remained unclear.

Conclusion: Searching for clinical predictors of gastrointestinal bleeding can identify patients receiving oral anticoagulants who is need of intensive monitoring risk factors to prevent the development of life-threatening bleeding and to provide with adequate anticoagulant therapy.