Key result
Vitamin K antagonists remain essential for mechanical heart valves and preferred over DOACs in rheumatic atrial fibrillation and high-risk triple-positive antiphospholipid syndrome.
Why the study?
Although DOACs have transformed anticoagulation, their success cannot be extrapolated to every thrombotic substrate, motivating an examination of the contemporary boundaries of warfarin and VKA therapy.
In which contemporary cardiovascular and thrombotic substrates does vitamin K antagonist therapy remain necessary, preferred, replaceable, or uncertain compared with direct oral anticoagulants?
In which contemporary cardiovascular and thrombotic substrates does vitamin K antagonist therapy remain necessary, preferred, replaceable, or uncertain compared with direct oral anticoagulants?
Contemporary anticoagulation requires a substrate-centered approach wherein vitamin K antagonists remain mandatory for mechanical heart valves and preferred for rheumatic mitral stenosis-associated atrial fibrillation and high-risk triple-positive antiphospholipid syndrome, despite widespread replacement by direct oral anticoagulants in conventional atrial fibrillation.
Warfarin is one of the most enduring drugs in cardiovascular medicine. Although direct oral anticoagulants (DOACs) have transformed anticoagulation, especially in atrial fibrillation (AF) eligible for DOAC therapy, their success cannot be extrapolated to every thrombotic substrate. This review examines the contemporary boundaries of warfarin and vitamin K antagonist (VKA) therapy. Mechanical heart valves remain the clearest setting in which lifelong international normalized ratio (INR)-guided VKA therapy is required; randomized attempts to substitute dabigatran or apixaban have failed. In rheumatic heart disease-associated AF, INVICTUS favored VKA therapy over rivaroxaban, supporting the VKA class rather than warfarin specifically. High-risk thrombotic antiphospholipid syndrome, particularly triple-positive disease, is another VKA-preferred setting. Left ventricular thrombus (LVT) occupies an evolving position in which warfarin remains established, while randomized evidence supports rivaroxaban as a potential alternative in selected acute post-myocardial infarction LVT. Pregnancy with mechanical valves requires dynamic maternal–fetal risk balancing, whereas advanced chronic kidney disease and dialysis represent areas of uncertainty rather than intrinsic indications for warfarin. The global relevance of warfarin also depends on total anticoagulation burden, including INR monitoring, travel, treatment continuity, quality of anticoagulation, and reversal capacity. The persistence of VKA efficacy in selected highly thrombogenic environments raises a biologically plausible hypothesis that broader suppression of vitamin K-dependent factors may matter, but this mechanism is not established by clinical trials. Contemporary anticoagulation should therefore be substrate-centered: VKA therapy remains necessary in some conditions, preferred in others, increasingly replaceable in several, and uncertain in a few.
No takes yet. Share an insight, caveat, or question.
Leite et al. (2026) conducted a review in Thromboembolic cardiovascular conditions requiring oral anticoagulation (mechanical heart valves, rheumatic heart disease-associated atrial fibrillation, antiphospholipid syndrome, left ventricular thrombus). Warfarin and vitamin K antagonists (VKAs) vs. Direct oral anticoagulants (DOACs: dabigatran, rivaroxaban, apixaban, edoxaban) was evaluated. Vitamin K antagonists remain essential for mechanical heart valves and preferred over DOACs in rheumatic atrial fibrillation and high-risk triple-positive antiphospholipid syndrome.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: