Is prophylactic anticoagulation (blood thinner) therapy safe in patients with infective endocarditis (infection of the heart valves) and septic embolism (infection-related blood clots)?

From the Guidelines

Prophylactic anticoagulation is generally not recommended in patients with infective endocarditis and septic embolism due to increased risk of hemorrhagic complications. In these patients, the risk of bleeding, particularly intracranial hemorrhage, often outweighs the potential benefits of preventing further embolic events. For patients already on anticoagulation therapy (such as those with mechanical heart valves or atrial fibrillation), the decision becomes more complex and requires careful consideration of individual risk factors, as stated in the 2014 AHA/ACC guideline for the management of patients with valvular heart disease 1.

The evidence suggests that the routine use of anticoagulation does not reduce the incidence of emboli in patients with native valve endocarditis (NVE) who have no other indication for anticoagulation 1. Furthermore, continuing anticoagulant therapy in the face of infective endocarditis (IE) potentially increases the risk of hemorrhagic transformation of an embolic stroke or accentuation of bleeding from septic arteritis or mycotic aneurysms should they occur 1.

If anticoagulation is deemed necessary, the choice of agent and timing should be carefully considered. Unfractionated heparin may be preferred over other agents as it has a shorter half-life and can be reversed quickly if bleeding occurs. The timing of anticoagulation should be delayed until after the period of highest risk for hemorrhagic transformation of embolic lesions, typically at least 2 weeks after a cerebral embolic event. This approach is supported by the pathophysiology of infective endocarditis, where vegetations on heart valves are friable and prone to fragmentation, and septic emboli can cause tissue necrosis and vessel wall weakening, increasing bleeding risk when anticoagulants are administered.

Decisions about continued anticoagulation and antiplatelet therapy should ultimately be directed by the patient’s consulting cardiologist and cardiothoracic surgeon in consultation with a neurology specialist if neurological findings are clinically present or noted on imaging, as recommended by the 2014 AHA/ACC guideline 1. The use of anticoagulants in prosthetic valve endocarditis (PVE) must also steer a path between the potential for thromboembolism and the risk of serious bleeding, including intracranial hemorrhage, as discussed in the antithrombotic and thrombolytic therapy for valvular disease guidelines 1.

Key considerations include:

• The risk of thromboembolic events in PVE is higher than that in native valve endocarditis 1
• Antimicrobial therapy remains the mainstay of embolization prevention; delay in therapy is related to the frequency of embolic stroke within 3 days of diagnosis 1
• The majority of studies suggest the risk of continuing anticoagulation in this disorder outweighs the potential benefits 1
• The consequences of intracranial hemorrhage may be irreversible and not infrequently fatal 1

Overall, the management of anticoagulation in patients with infective endocarditis and septic embolism requires a careful balance of the risks and benefits, with a focus on minimizing the risk of hemorrhagic complications while preventing further embolic events.

From the Research

Safety of Prophylactic Anticoagulation in Infective Endocarditis

• The use of anticoagulation therapy in patients with infective endocarditis (IE) and septic embolism is a topic of ongoing debate 2, 3.
• Observational studies have shown that anticoagulant treatment failed to reduce the risk of ischemic stroke in patients with IE, suggesting that IE alone is not an indication for anticoagulation 2.
• However, in patients who have other indications for antiplatelet or anticoagulant treatment, the continuation of this treatment is deemed safe in the absence of hemorrhagic complications 3.

Embolic Complications and Bleeding Risk

• A pilot study found that patients with IE receiving anticoagulant/antiplatelet therapy may be at an increased risk for embolic episodes versus those who are not 4.
• Another study found that long-term daily use of aspirin does not reduce the risk of embolic events but may be associated with a higher risk of bleeding in patients with endocarditis 5.
• A case report suggests that anticoagulation in patients with infective endocarditis and embolic stroke may cause no harm and could potentially offer some benefit, although more research is needed to confirm this 6.

Clinical Considerations

• A multidisciplinary approach and patient engagement are required to determine the timing and regimen of anticoagulation in patients with IE, especially in specific situations such as cerebral embolism or ischemic stroke 2.
• Individualized strategies on anticoagulation management of IE should be based on clinical evaluation, available evidence, and patient engagement, and ultimately be developed by the multidisciplinary team 2.