Risk stratification for discontinuation of warfarin therapy with respect to the requirement for heparin bridging
| High risk of thromboembolism | Low risk of thromboembolism |
| Prosthetic metal heart valve in mitral or aortic* position | Xenograft heart valve |
| Prosthetic heart valve and atrial fibrillation | |
| Atrial fibrillation and mitral stenosis | |
| Atrial fibrillation with previous stroke or transient ischaemic attack+3 or more of: Congestive cardiac failure Hypertension† Age>75 years Diabetes mellitus | Atrial fibrillation without high-risk factors (CHADS2 <4) |
| Atrial fibrillation and previous stroke or transient ischaemic attack within 3 months | |
| <3 months after venous thromboembolism‡ | >3 months after venous thromboembolism |
| Previous venous thromboembolism on warfarin, and target INR now 3.5 |
Thrombophilia syndromes do not usually require heparin bridging, but individual cases should be discussed with a haematologist.
*Heparin bridging for a metal aortic valve is recommended by European Society of Cardiology and the European Association for Cardio-Thoracic Surgery guidelines 2017,33 but this varies between international guidelines31 32 and local guidance should be established in conjunction with cardiology or cardiothoracic services.
†Blood pressure>140/90 mm Hg or on antihypertensive medication.
‡The majority of patients are now on direct oral anticoagulants for venous thromboembolism and bridging is not appropriate. Consider deferring a high-risk procedure beyond 3 months therapy in this high-risk group for thromboembolism.
INR, international normalised ratio.