Design and rationale of the GUARD-OAC: A randomized controlled trial evaluating proton pump inhibitor cotherapy for gastrointestinal protection in patients requiring direct oral anticoagulants. - Ahn HJ; Lee SR; Kwon S; Rhee TM; Lee YS; Han SJ; Kang KW; Shim J; Yu HT; Oh IY; Park HS; Park JK; et al. (American heart journal, 2026)