What is the treatment plan for post-mitral valve replacement (MVR) prosthetic valve thrombosis, specifically the dose of reteplase for stuck valve thrombosis?

Reteplase Dosing for Prosthetic Valve Thrombosis

For prosthetic mitral valve thrombosis, reteplase should be administered as a 10 mg bolus followed by 10 mg 30 minutes later, with close monitoring for resolution of valve thrombosis via echocardiography.

Assessment and Decision Making for Prosthetic Valve Thrombosis

Prosthetic valve thrombosis (PVT) is a life-threatening complication requiring prompt intervention. The management approach depends on several factors:

Indications for Thrombolysis vs. Surgery

Thrombolysis is appropriate in the following scenarios 1:

• Critically ill patients with serious comorbidities who are unlikely to survive surgery
• Situations where surgical treatment is not immediately available
• Thrombosis of tricuspid or pulmonary valve replacements
• Left-sided prosthetic valve thrombosis with recent onset (<14 days) of NYHA class I-II symptoms and small thrombus (<0.8 cm) 1

Surgery is preferred for 1:

• Obstructive thrombosis in critically ill patients (NYHA class III-IV) without serious comorbidities
• Large thrombus burden
• Contraindications to thrombolysis

Reteplase Protocol for Prosthetic Valve Thrombosis

When thrombolysis is deemed appropriate for prosthetic valve thrombosis, the recommended reteplase dosing protocol is:

1. Initial bolus: 10 mg IV over 2 minutes
2. Second bolus: 10 mg IV over 2 minutes, administered 30 minutes after the first dose

This dosing is adapted from the standard reteplase protocol for acute coronary syndromes but applied to valve thrombosis based on clinical experience.

Monitoring During Thrombolysis

• Continuous cardiac monitoring and frequent vital sign checks
• Serial echocardiography (TTE/TEE) to assess thrombus resolution and valve function 1
• Monitor for bleeding complications at all sites
• Check aPTT before initiating heparin after thrombolysis

Post-Thrombolysis Management

After successful thrombolysis 1:

1. Begin heparin infusion (without loading dose) when aPTT decreases to less than twice normal
2. Target aPTT 1.5-2 times normal (55-80 seconds)
3. Initiate warfarin simultaneously with heparin
4. For mechanical mitral valves, target INR of 3.0 1
5. Add aspirin 75-100 mg daily 1
6. Perform monthly echocardiography for the first 6 months, then every 6 months 1

Complications and Their Management

Bleeding Complications

• Minor bleeding at puncture sites: Apply local pressure
• Major bleeding: Immediately terminate thrombolysis, consider fresh-frozen plasma or prothrombin complex concentrate 1

Embolic Complications

• Monitor for signs of systemic embolism
• If stroke occurs, obtain immediate CT scan to rule out hemorrhage 1
• If non-hemorrhagic, anticoagulation may be continued

Important Considerations

• Thrombolysis has shown success rates of up to 85.3% in some studies 2
• Recurrent thrombosis can occur in approximately 16% of cases but can often be successfully retreated with thrombolysis 2
• DOACs (direct oral anticoagulants) are contraindicated for mechanical valve prostheses 1, 3
• Close monitoring of anticoagulation status is essential to prevent recurrent thrombosis

Thrombolysis with reteplase offers a non-invasive alternative to surgery with reasonable success rates when used in appropriate patients with prosthetic valve thrombosis.