Effectiveness and Safety of Direct Oral Anticoagulants Versus Warfarin in Patients With Mechanical Heart Valves: A Systematic Review

Patients with mechanical heart valves require lifelong anticoagulation primarily due to the thrombogenic nature of these valves. Warfarin has been the mainstay of therapy, but its drug-drug interactions and frequent monitoring requirements have diverted attention toward DOACs (direct oral anticoagulants) such as apixaban, rivaroxaban, and dabigatran. However, the use of DOACs in this group of patients remains controversial, particularly after negative outcomes in earlier trials. This systematic review focuses on the efficacy of DOACs compared to warfarin for preventing thromboembolic events and associated bleeding risks in patients with mechanical heart valves. Most evidence comes from observational studies and meta-analyses. More limited data exist for patients with mechanical heart valves. We systematically searched PubMed, PubMed Central, and Google Scholar for English-language studies published between January 2015 and May 5, 2025. Eligible studies included randomized controlled trials (RCTs), observational studies, systematic reviews, and meta-analyses comparing DOACs and warfarin in adults with mechanical heart valves and related comorbidities such as atrial fibrillation and valvular heart disease. Articles were screened and assessed using standard quality appraisal tools. We included three observational studies, two RCTs, and six systematic reviews and meta-analyses. Most of the studies favored warfarin as the standard therapy for patients with mechanical heart valves, while DOACs showed relatively inferior outcomes. Current practice guidelines from the American College of Cardiology Foundation/American Heart Association Task Force suggest warfarin as the standard treatment for patients with mechanical heart valves. There is a further need for long-term, high-quality clinical trials using a newer generation of DOACs among this high-risk group.