Do patients require temporary anticoagulation (anticoagulant therapy) after annuloplasty for mitral valve repair?

From the Guidelines

Patients typically need temporary anticoagulation after mitral valve annuloplasty, with a recommended duration of at least 3 months and up to 6 months, as supported by the 2017 AHA/ACC focused update 1. The standard regimen includes warfarin (Coumadin) with a target INR of 2.0-3.0 for approximately 3 months post-procedure. During the initial hospital stay, patients often receive bridging therapy with intravenous unfractionated heparin or subcutaneous low molecular weight heparin (such as enoxaparin 1 mg/kg twice daily) until the INR reaches therapeutic range on warfarin. After the 3-month period, most patients can transition to aspirin 81-325 mg daily for long-term therapy, unless they have other indications for continued anticoagulation such as atrial fibrillation. This temporary anticoagulation is necessary because the newly repaired valve and implanted annuloplasty ring present a thrombogenic surface until endothelialization occurs, typically within 3 months. Additionally, patients may have post-operative atrial fibrillation or reduced mobility that increases thrombosis risk. Regular INR monitoring is essential during the warfarin treatment period, with testing initially twice weekly, then weekly once stable, adjusting the dose as needed to maintain the target range. Some key points to consider include:

• The 2017 AHA/ACC focused update recommends anticoagulation with a VKA to achieve an INR of 2.5 for at least 3 months and up to 6 months after surgical bioprosthetic MVR or AVR in patients at low risk of bleeding 1.
• The potential benefit of anticoagulation therapy must be weighed against the risk of bleeding, and patients with a bioprosthetic MVR who received anticoagulation had a lower rate of thromboembolism than those who did not receive therapy with VKA 1.
• Aspirin 75 mg to 100 mg daily is recommended in addition to anticoagulation with a VKA in patients with a mechanical valve prosthesis, and is also reasonable in all patients with a bioprosthetic aortic or mitral valve 1. The previous guideline from 2008 also supports the use of oral anticoagulation for the first 3 months after MV repair, with a Level of Evidence of C 1. However, the more recent and higher-quality study from 2017 takes precedence in guiding clinical decision-making 1.

From the Research

Anticoagulation After Mitral Valve Repair

• The need for temporary anticoagulant after annuloplasty for mitral valve repair is a topic of discussion among cardiologists and surgeons 2.
• A study published in the Journal of Cardiac Surgery found that postoperative warfarin use was associated with a reduced composite of bleeding and thromboembolic complications, and superior long-term survival 2.
• However, the use of anticoagulants in patients with atrial fibrillation who have undergone mitral valve repair is not well-established, and guidelines are limited 3.
• Another study found that the overall use of anticoagulation was unchanged between 2014 and 2018, and roughly 30% of patients were not treated with any anticoagulant within 90 days of discharge, despite an elevated stroke risk in the cohort 3.

Durability of Annuloplasty

• The durability of mitral valve repair with complete ring or flexible band annuloplasty in patients with atrial functional mitral regurgitation associated with atrial fibrillation is excellent, with freedom from moderate/severe mitral regurgitation at 10 years being 89% 4.
• A study published in The Journal of Thoracic and Cardiovascular Surgery found that the presence of postoperative atrial fibrillation was not associated with a greater likelihood of recurrence of mitral regurgitation 4.
• Another study found that patients with atrial functional mitral regurgitation do well after mitral valve repair using an annuloplasty ring, with low rates of reoperation, mortality, and recurrence of mitral regurgitation 5.

Surgical Strategy and Outcomes

• The optimal strategy for functional mitral regurgitation remains unclear, and outcomes are poor 5.
• A study published in The Journal of Thoracic and Cardiovascular Surgery found that subdividing patients with functional mitral regurgitation caused by atrial versus ventricular pathology might be important, and that patients with atrial functional mitral regurgitation have excellent outcomes after mitral valve repair using an annuloplasty ring 5.
• The use of anticoagulants in patients with atrial fibrillation who have undergone mitral valve repair should be considered on a case-by-case basis, taking into account the individual patient's risk factors and medical history 3, 2.