Is it necessary to discontinue anticoagulation (blood thinner) therapy in patients with aortic metallic valve replacements before undergoing dental procedures?

Anticoagulation Management for Dental Procedures in Patients with Aortic Mechanical Valve Replacement

Do not discontinue anticoagulation for dental procedures in patients with aortic metallic valve replacements—continue warfarin at therapeutic INR levels, as bleeding from dental work is easily controlled locally and the thromboembolic risk of stopping anticoagulation outweighs the minimal bleeding risk. 1

Primary Recommendation

For patients with mechanical heart valves undergoing minor dental procedures (such as dental extractions, dental cleaning, or simple treatment for dental caries), continuation of vitamin K antagonist (VKA) anticoagulation with a therapeutic INR is the Class I recommendation. 1 This is the highest level of guideline recommendation from both the 2014 and 2021 ACC/AHA guidelines.

Rationale for Continuing Anticoagulation

• Bleeding from dental procedures is easily controlled using local hemostatic measures and tranexamic acid mouthwashes, making the bleeding risk minimal and manageable. 1, 2

• The thromboembolic risk of interrupting anticoagulation, even briefly, poses a greater threat to patient morbidity and mortality than the bleeding risk from dental work. 1

• Antithrombotic therapy should not be stopped for procedures where bleeding is unlikely or would be inconsequential if it occurred, which specifically includes dental cleaning and simple dental caries treatment. 1

When Interruption May Be Considered (Major Oral Surgery Only)

For major oral and maxillofacial surgery (not routine dental procedures), temporary interruption of VKA anticoagulation without bridging agents is recommended only in patients with a bileaflet mechanical aortic valve replacement (AVR) and no other risk factors for thromboembolism. 1

Risk Stratification for Interruption

Low-risk patients (can interrupt without bridging):

• Bileaflet mechanical AVR in aortic position 1
• No atrial fibrillation 1
• No prior thromboembolism 1
• No hypercoagulable condition 1
• Normal left ventricular function (LVEF >30%) 1
• No left atrial enlargement 3
• Only one mechanical valve 1

High-risk patients (require bridging if interruption necessary):

• Mechanical mitral valve replacement 1
• Older-generation mechanical valves (caged ball, caged disk) 1
• Mechanical AVR with any thromboembolic risk factor 1
• Multiple mechanical valves 1

Practical Management Protocol

For Routine Dental Procedures (Extractions, Cleanings, Fillings)

1. Check INR within 24-72 hours before the procedure to ensure it is in therapeutic range (2.0-3.0 for most aortic valves). 1, 4

2. Continue warfarin at the usual dose without interruption. 1

3. Ensure INR is <4.0 at the time of procedure—if INR is ≥4.0, consider delaying the procedure or adjusting warfarin dose. 2

4. Use local hemostatic measures: Apply local pressure, hemostatic agents, and sutures as needed at the surgical site. 1, 2

5. Prescribe tranexamic acid mouthwash (10 mL of 5% solution, four times daily for 5-7 days post-procedure) to minimize bleeding. 2

For Major Oral/Maxillofacial Surgery (If Truly Necessary)

Only for low-risk patients (bileaflet AVR, no risk factors):

1. Stop warfarin 2-4 days before surgery to allow INR to fall to <1.5. 1

2. Do not use bridging anticoagulation in these low-risk patients—the inconvenience and expense of bridging can be avoided. 1

3. Restart warfarin 12-24 hours after surgery as soon as bleeding risk allows. 1

4. Monitor INR closely until therapeutic range is re-established. 4

For high-risk patients (mitral valve, older valves, or AVR with risk factors):

1. Stop warfarin 2-4 days before surgery. 1

2. Initiate bridging anticoagulation with either intravenous unfractionated heparin (UFH) or subcutaneous low-molecular-weight heparin (LMWH) when INR falls below therapeutic range. 1

3. Stop LMWH ≥12 hours before procedure or stop UFH 4 hours before procedure. 1

4. Resume bridging anticoagulation 12-24 hours post-operatively and restart warfarin simultaneously. 1

5. Continue bridging until INR returns to therapeutic range. 1

Critical Pitfalls to Avoid

Never use direct oral anticoagulants (DOACs) in patients with mechanical valves—dabigatran, apixaban, and rivaroxaban are contraindicated due to excessive thrombotic complications and increased bleeding risk demonstrated in the RE-ALIGN trial. 1, 5

Do not use dual antiplatelet therapy (DAPT) alone as a substitute for warfarin in mechanical valve patients undergoing procedures—the PROACT trial showed excess cerebral thromboembolic events (3.12% vs. 0.29% per patient-year, p=0.02) with DAPT compared to warfarin. 6

Avoid high-dose vitamin K (>2 mg) for INR reversal, as this creates difficulty re-establishing therapeutic anticoagulation post-procedure. 1

Do not routinely discontinue anticoagulation for "minor" procedures—this outdated practice increases thromboembolic risk without meaningful reduction in bleeding complications. 1

Emergency Reversal (If Severe Bleeding Occurs)

For life-threatening bleeding during or after a dental procedure in a patient on warfarin:

1. Administer 4-factor prothrombin complex concentrate (PCC) intravenously—onset of effect within 5-15 minutes, duration 12-24 hours. 1

2. Add low-dose oral vitamin K (1-2 mg) to prolong the reversal effect beyond the short half-life of PCC. 1

3. Fresh frozen plasma is an alternative if PCC unavailable, though onset is slower (1-4 hours) and duration shorter (<6 hours). 1

4. Restart anticoagulation as soon as bleeding is controlled, balancing the location and severity of bleeding against thromboembolic risk. 1