Direct-acting oral anticoagulants versus warfarin in relation to risk of gastrointestinal bleeding: a systematic review and meta-analysis of randomized controlled trials

Background Direct-acting oral anticoagulants (DOACs) are increasingly used, with studies showing a lower risk of gastrointestinal bleeding (GIB), but overall data for GIB risk remains debatable. The objective was to assess non-fatal and fatal GIB risk in patients on DOACs compared with warfarin from randomized clinical trials (RCTs). Methods RCTs comparing warfarin and DOACs for various indications (atrial fibrillation, thromboembolism, insertion of mechanical heart valves) were included. The primary endpoint was any GIB event. Other clinical events, such as fatal GIB, and effects of age (<= 60 years or older), time in therapeutic range for warfarin, and choice of individual DOACs on GIB risk, were also assessed. Results 14 RCTs were included, comprising 87,407 participants (DOACs n=46,223, warfarin control n=41,184). The risk of GIB with DOACs was similar to that of warfarin (relative risk [RR] 1.04, 95% confidence interval [CI] 0.85-1.27). Compared with warfarin, rivaroxaban (RR 1.23, 95%CI 1.03-1.48) and dabigatran (RR 1.38, 95%CI 1.12-1.71) had a higher risk of any GIB, whereas fatal GIB risk was lower in the DOACs group (RR 0.36, 95%CI 0.15-0.82). The risk of DOAC-related fatal GIB was lower in patients aged <= 60 years and in those with poor coagulation control (RR 0.39, 95%CI 0.15-0.98). Conclusions DOACs compared with warfarin have a lower risk of fatal GIB, especially in those aged <60 years and those with poor coagulation control. However, the risk of GIB was comparable with warfarin and DOACs, except for rivaroxaban and dabigatran.