From the Guidelines
The International Normalized Ratio (INR) goal for a bioprosthetic aortic valve is 2.5.
Rationale
- The American College of Cardiology/American Heart Association (ACC/AHA) guidelines recommend an INR goal of 2.5 for patients with a bioprosthetic aortic valve, particularly in the first 3 to 6 months after surgery 1.
- This recommendation is based on observational studies that have reported an increased risk of ischemic stroke early after bioprosthetic valve surgery 1.
- The potential benefit of anticoagulation therapy must be weighed against the risk of bleeding, particularly in patients who are at low risk for thromboembolism 1.
- After 3 to 6 months, long-term therapy with only aspirin 75 to 100 mg daily is recommended 1.
- The ACC/AHA guidelines also provide a summary of antithrombotic therapy for prosthetic valves, including the recommended INR goal for bioprosthetic valves 1.
Key Points
- INR goal of 2.5 for bioprosthetic aortic valve
- Recommended for at least 3 months and up to 6 months after surgery
- Aspirin 75 to 100 mg daily recommended after 3 to 6 months
- Potential benefit of anticoagulation must be weighed against risk of bleeding
- Guidelines provide a summary of antithrombotic therapy for prosthetic valves, including recommended INR goals 1
From the Research
International Normalized Ratio (INR) Goal for Bioprosthetic Aortic Valve
- The INR goal for a bioprosthetic aortic valve is not explicitly stated in the provided studies, as most of the studies focus on mechanical heart valves.
- However, one study 2 mentions that patients with bioprosthetic valves in the aortic position may be at risk for thromboemboli during the first 3 months after operation, and that oral anticoagulants at an INR of 2.0 to 2.3 were as effective as an INR of 2.5 to 4.0 and were associated with fewer bleeding complications during the first 3 months after operation.
- Another study 2 suggests that aspirin may reduce the long-term frequency of thromboembolism in patients with bioprosthetic valves.
Comparison with Mechanical Valves
- The INR goals for mechanical aortic valves are more established, with a range of 2.0 to 3.0 for low-risk patients and 2.5 to 3.5 for high-risk patients 3.
- Some studies suggest that lower INR targets may be safe and feasible for low-risk patients with mechanical aortic valves, with similar thrombotic events and reduced bleeding occurrence 4.
- However, the optimal INR goal for bioprosthetic aortic valves remains unclear, and more research is needed to determine the best approach for anticoagulation therapy in these patients.