Is anticoagulation reversal recommended in patients with mechanical heart valves undergoing surgery?

From the Guidelines

Anticoagulation reversal is generally not recommended for patients with mechanical heart valves undergoing surgery, as these patients require continuous anticoagulation to prevent potentially fatal valve thrombosis. Instead, a carefully managed perioperative bridging strategy is typically employed. For most surgeries, warfarin (the standard anticoagulant for mechanical valves) should be discontinued 2 to 4 days before the procedure to allow the INR to fall below 1.5, as recommended by the 2021 ACC/AHA guideline for the management of patients with valvular heart disease 1. During this period, bridging with intravenous unfractionated heparin or subcutaneous low molecular weight heparin is recommended, especially for patients with mitral mechanical valves or older aortic mechanical valves who are at higher thrombotic risk. Some key points to consider in the management of anticoagulation in patients with mechanical heart valves undergoing surgery include:

• The risk of thromboembolism after stopping anticoagulation with a vitamin K antagonist (VKA) is small if the drug is withheld for only a few days in patients with a bileaflet mechanical aortic valve replacement (AVR) and no other risk factors 1.
• In patients with mechanical valves on long-term VKA therapy who require emergency surgery or invasive procedures, anticoagulation can be reversed by administration of intravenous prothrombin complex concentrate, which replaces the coagulation factors that are decreased by VKAs 1.
• The decision to use bridging anticoagulation should be individualized and should account for the trade-offs between thrombosis and bleeding, as there are no randomized comparative-effectiveness trials evaluating a strategy of bridging versus no bridging in adequate numbers of patients with prosthetic heart valves needing temporary interruption of oral anticoagulant therapy 1.
• Administration of fresh frozen plasma or prothrombin complex concentrate is reasonable in patients with mechanical valves receiving VKA therapy who require emergency noncardiac surgery or invasive procedures 1. Heparin should be stopped 4-6 hours (unfractionated) or 12 hours (LMWH) before surgery and resumed 12-24 hours after surgery when hemostasis is adequate. Warfarin should be restarted within 24 hours post-surgery. For minor procedures with low bleeding risk, warfarin may be continued with target INR temporarily reduced to 2.0-2.5. Complete reversal with vitamin K or prothrombin complex concentrate is reserved only for life-threatening bleeding or emergency surgery, as it creates a high-risk period for valve thrombosis that can lead to catastrophic outcomes including stroke, valve dysfunction, or death.

From the FDA Drug Label

For all patients with mechanical prosthetic heart valves, warfarin is recommended. For patients with a St. Jude Medical (St. Paul, MN) bileaflet valve in the aortic position, a target INR of 2.5 (range, 2.0 to 3. 0) is recommended. For patients with tilting disk valves and bileaflet mechanical valves in the mitral position, the 7th ACCP recommends a target INR of 3.0 (range, 2.5 to 3.5).

The FDA drug label does not directly answer the question of whether anticoagulation reversal is recommended in patients with mechanical heart valves undergoing surgery. However, it provides guidance on the management of anticoagulation in patients with mechanical heart valves, suggesting that warfarin is recommended for these patients.

• Key points:
  • Warfarin is recommended for patients with mechanical prosthetic heart valves.
  • Target INR ranges are provided for different types of mechanical heart valves.
  • The label does not provide specific guidance on anticoagulation reversal for surgery. 2

From the Research

Anticoagulation Reversal in Patients with Mechanical Heart Valves Undergoing Surgery

• The decision to reverse anticoagulation in patients with mechanical heart valves undergoing surgery depends on various factors, including the type of surgery, the patient's risk of thromboembolism, and the risk of bleeding 3, 4, 5, 6, 7.
• Studies have shown that reversing anticoagulation with prothrombin complex concentrate (PCC) or fresh frozen plasma (FFP) can be effective in patients with mechanical heart valves undergoing surgery 3.
• However, the optimal strategy for perioperative anticoagulation management is still debated, and different guidelines and expert opinions may vary 4, 5, 6.
• A survey of Italian physicians found that the majority of respondents would use low-molecular-weight heparin (LMWH) or subcutaneous unfractionated heparin (UH) as the preferred pre- and postoperative anticoagulant in patients with mechanical heart valves undergoing surgery 5.
• Another study found that significant variation in practice exists among clinicians caring for patients with mechanical heart valves who require temporary cessation of their warfarin therapy 6.
• The risk of thromboembolic and bleeding complications in patients with mechanical heart valve prostheses undergoing non-cardiac surgery under different regimens of perioperative anticoagulation has been studied, and the results suggest that minor surgical procedures can be performed safely without discontinuing anticoagulation, while major non-cardiac surgery may require discontinuing oral anticoagulation and starting perioperative intravenous heparin to minimize bleeding and thromboembolic risks 7.

Perioperative Anticoagulation Management

• The management of perioperative anticoagulation in patients with mechanical heart valves undergoing surgery involves careful consideration of the patient's individual risk factors and the type of surgery being performed 3, 4, 5, 6, 7.
• Different strategies for perioperative anticoagulation management have been proposed, including the use of LMWH or UH, and the timing of anticoagulation reversal 4, 5, 6.
• The use of PCC or FFP for anticoagulation reversal has been studied, and the results suggest that these agents can be effective in reversing anticoagulation in patients with mechanical heart valves undergoing surgery 3.

Risks and Complications

• The risks and complications associated with perioperative anticoagulation management in patients with mechanical heart valves undergoing surgery include thromboembolic events, bleeding complications, and hospital mortality 3, 4, 5, 6, 7.
• The risk of thromboembolic complications is higher in patients with prosthetic mitral valve and atrial fibrillation, while the risk of bleeding complications is higher in patients undergoing major non-cardiac surgery 7.
• The timing of anticoagulation reversal and the use of perioperative intravenous heparin can help minimize the risk of bleeding and thromboembolic complications 4, 7.