Do I need to take daily low‑dose aspirin after mitral valve repair?

Aspirin After Mitral Valve Repair

For patients with mitral valve repair who remain in normal sinus rhythm, daily low-dose aspirin (75-100 mg) is reasonable and provides adequate antithrombotic protection without the bleeding risks of warfarin. 1

The Core Recommendation

Aspirin 75-100 mg daily is the appropriate long-term therapy after mitral valve repair for patients without atrial fibrillation or other high-risk features. 2, 1 This recommendation is based on the substantially lower thrombotic risk of repaired native valves compared to prosthetic valve replacements, where the preserved valve architecture reduces thromboembolic potential. 1

Initial Post-Operative Period (First 3 Months)

• Start aspirin 75-100 mg daily immediately after surgery rather than warfarin for patients in normal sinus rhythm with a prosthetic annuloplasty band. 1
• The American College of Chest Physicians specifically recommends aspirin over warfarin during this period due to lower thrombotic risk compared to prosthetic valves. 1
• A study of 162 patients demonstrated significantly fewer thromboembolic events with antiplatelet therapy compared to warfarin (RR 0.16,95% CI 0.03-0.86), with no difference in hemorrhage rates. 1
• The bleeding risk with warfarin outweighs benefits in this lower-risk population. 1

Long-Term Management (Beyond 3 Months)

• Continue aspirin 75-100 mg daily indefinitely for patients who remain in normal sinus rhythm. 2, 1
• The annual thromboembolic risk after mitral valve repair is substantially lower than after valve replacement, supporting aspirin alone rather than warfarin. 1
• This provides adequate stroke prevention while minimizing bleeding complications. 1

Critical Exceptions Requiring Warfarin Instead of Aspirin

Switch to warfarin (INR 2.0-3.0) if any of the following develop: 1

• Atrial fibrillation (the most common reason for warfarin) 1, 3
• Previous thromboembolic event 1
• Left ventricular systolic dysfunction 1
• Hypercoagulable condition 1
• Left atrial thrombus 1

In these situations, the stroke risk is driven by the comorbidity rather than the repaired valve itself, making warfarin mandatory. 1

Key Clinical Pitfalls to Avoid

• Always verify the patient is in normal sinus rhythm before continuing aspirin-only therapy. 1 If atrial fibrillation is present or develops at any point, warfarin becomes mandatory regardless of the valve repair. 1
• Do not confuse mitral valve repair with mitral valve replacement—replacement requires more aggressive anticoagulation (warfarin for 3-6 months minimum for bioprosthetic valves, lifelong warfarin for mechanical valves). 4, 3
• The aspirin-only strategy applies specifically to repair without the high-risk features listed above. 1

Supporting Evidence Quality

The 2020 ACC/AHA guidelines provide the most current framework, designating aspirin 75-100 mg daily as reasonable (Class IIa, Level B-R) for bioprosthetic and repaired valves in the absence of other anticoagulation indications. 2 This recommendation extends logically to mitral valve repair, where the native valve architecture is preserved and thrombotic risk is lower than with any prosthetic material. 1