When is it recommended to continue Coumadin (warfarin) for a patient with a history of atrial fibrillation (AF) and hypertension who is scheduled to undergo a thyroidectomy in three weeks?

Perioperative Warfarin Management for Thyroidectomy in Atrial Fibrillation

For a patient with atrial fibrillation and hypertension scheduled for thyroidectomy in three weeks, warfarin should be stopped 5 days before surgery and resumed within 24 hours after the procedure when adequate hemostasis is achieved, without bridging anticoagulation given the low-to-moderate thromboembolic risk. 1, 2

Risk Stratification

Your patient requires assessment of thromboembolic risk to determine if bridging therapy is necessary:

• Patients with nonvalvular atrial fibrillation at low-to-moderate thromboembolic risk (CHA₂DS₂-VASc score <7 or CHADS₂ score <5) should undergo perioperative management without bridging therapy. 2

• Bridging therapy with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) is only recommended for patients with mechanical heart valves, recent stroke or TIA (<3 months), very high thromboembolic risk (CHA₂DS₂-VASc score ≥7 or CHADS₂ score of 5-6), or history of perioperative stroke. 2

• Your patient with atrial fibrillation and hypertension likely has a CHA₂DS₂-VASc score of 2-3 (1 point for hypertension, 1-2 points depending on age and sex), placing them in the low-to-moderate risk category where bridging is not indicated. 1, 2

Specific Timing Protocol

Warfarin Discontinuation:

• Stop warfarin 5 days before the scheduled thyroidectomy. 1, 2
• This allows the INR to return to near-normal levels (typically <1.5) by the time of surgery. 1

Warfarin Resumption:

• Resume warfarin within 24 hours after surgery once adequate hemostasis is achieved. 1, 2
• The surgeon should confirm that bleeding risk at the operative site is controlled before restarting anticoagulation. 1

Why Bridging is NOT Recommended

• For patients with atrial fibrillation who do not have mechanical prosthetic heart valves, it is reasonable to interrupt anticoagulation for up to 1 week without substituting heparin for surgical or diagnostic procedures that carry a risk of bleeding. 1

• The American College of Cardiology specifically recommends that patients with nonvalvular atrial fibrillation at low-to-moderate thromboembolic risk should undergo perioperative management without bridging therapy. 2

• Bridging anticoagulation increases bleeding risk without providing significant thromboembolic protection in low-to-moderate risk patients. 2

Thyroidectomy-Specific Considerations

Thyroidectomy is considered a procedure with moderate bleeding risk where:

• The operative site is well-defined and accessible for local hemostatic measures. 1
• Postoperative bleeding in the neck can cause airway compromise, making meticulous hemostasis critical. 1
• The 5-day warfarin interruption period is appropriate for this procedure's bleeding risk profile. 1, 2

Common Pitfalls to Avoid

• Do not bridge with heparin or LMWH unless the patient has high-risk features (mechanical valve, recent stroke <3 months, CHA₂DS₂-VASc ≥7). 2

• Do not delay warfarin resumption unnecessarily beyond 24 hours post-procedure, as this increases thromboembolic risk without reducing bleeding complications. 2

• Do not restart warfarin if there are ongoing bleeding concerns at the surgical site—wait until the surgeon confirms adequate hemostasis. 1

• Inadequate risk assessment can lead to inappropriate bridging decisions that increase bleeding complications. 2

Monitoring Requirements

• Check INR just prior to the thyroidectomy to confirm it is <1.5 for safe surgery. 1
• After resuming warfarin, check INR within 3-5 days to ensure therapeutic anticoagulation is being re-established. 3
• Continue regular INR monitoring until stable therapeutic range (INR 2.0-3.0) is achieved. 1