Anticoagulation Therapy for Patients with Mechanical Heart Valves

Evidence Against DOACs in Mechanical Heart Valves

The American College of Cardiology and American Heart Association guideline explicitly states that for patients with a mechanical valve prosthesis, anticoagulation with the direct thrombin inhibitor, dabigatran, is contraindicated (Class III: Harm; Level of Evidence: B-R) 1, 2
The American College of Cardiology and American Heart Association guideline states that for patients with a mechanical valve prosthesis, the use of anti-Xa direct oral anticoagulants has not been assessed and is not recommended (Class III: Harm; Level of Evidence: C-EO) 1, 2

The RE-ALIGN trial showed an increase in thromboembolic and bleeding complications with dabigatran compared to warfarin in patients with mechanical heart valves, leading to early termination of the trial 3

The American College of Cardiology recommends that all patients with mechanical valves require lifelong anticoagulation with a Vitamin K antagonist (VKA) to decrease the incidence of thromboembolism and associated morbidity 1, 4
For patients with a mechanical aortic valve replacement without risk factors for thromboembolism, VKA therapy with a target INR of 2.5 (range 2.0-3.0) is recommended 4, 5
For patients with a mechanical aortic valve replacement with additional risk factors or an older-generation mechanical valve, a higher target INR of 3.0 (range 2.5-3.5) is recommended 4, 5
For patients with a mechanical mitral valve replacement, anticoagulation with a VKA to achieve an INR of 3.0 (range 2.5-3.5) is indicated 4

Regular INR monitoring is essential for patients with mechanical valves on VKA therapy 5
For patients with mechanical heart valves who experience a stroke or systemic embolic event while in therapeutic range on VKA anticoagulation, it is reasonable to increase the INR goal or add daily low-dose aspirin (75-100 mg), with assessment of bleeding risk 6
The addition of low-dose aspirin (75-100 mg daily) to VKA therapy may be considered in patients with a mechanical valve who are at low risk of bleeding 1, 4
For patients with a mechanical On-X AVR and no thromboembolic risk factors, a lower INR target (1.5-2.0) may be reasonable starting ≥3 months after surgery, with continuation of aspirin 75-100 mg daily 1, 4

For patients with mechanical heart valves undergoing minor procedures where bleeding is easily controlled, continuation of VKA anticoagulation with a therapeutic INR is recommended 6, 7
Bridging anticoagulation therapy during interruption of VKA therapy should be individualized based on valve type, position, and patient risk factors 7