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Otto et al 2020 ACC/AHA Guideline for the Management of Valvular Heart Disease February 2, 2021 Circulation. 2021;143:e72–e227. DOI: 10.1161/CIR.0000000000000923 e150 CLINICAL STATEMENTS AND GUIDELINES 11.6.2 Intervention Recommendation for Intervention for Mechanical Prosthetic Valve Thrombosis Referenced studies that support the recommendation are summarized in Online Data Supplement 38. COR LOE Recommendation 1 B-NR 1. For patients with a thrombosed left-sided mechanical prosthetic heart valve who present with symptoms of valve obstruction, urgent initial treatment with either slow-infusion, lowdose fibrinolytic therapy or emergency surgery is recommended.1–12 Synopsis Patients presenting with a thrombosed mechanical valve require urgent therapy. The 2 options of lowdose, continuous-infusion thrombolytic therapy or emergency surgery are both effective, with the decision to proceed with either one based on multiple clinical factors and local experience and expertise. Recommendation-Specific Supportive Text 1. The decision between surgery and systemic fibrinolysis for symptomatic left-sided mechanical valve thrombosis should be individualized (Table 23) after review by the heart valve team, while engaging the patient in a process of shared decision-making and accounting for local experience and expertise. The overall 30-day mortality rate with surgery is 10% to 15%, with a lower mortality rate of <5% in patients with NYHA class I or II symptoms.2,3,7 Recent studies using an echocardiogram-guided, slow-infusion, low-dose fibrinolytic protocol have shown hemodynamic success rates >90%, with embolic event rates <2% and major bleeding rates <2%.13 Systemic fibrinolysis is therefore an acceptable alternative to reoperation in patients at high or prohibitive surgical risk and in patients who have a small thrombus burden, mild HF symptoms (NYHA class I or II), and low bleeding risk. Absence of surgical expertise should be considered in the clinical decision-making process as a factor that favors thrombolytics, whereas recurrent valve thrombosis favors a surgical approach (Table 23). 11.7 Bioprosthetic Valve Thrombosis 11.7.1 Diagnosis of Bioprosthetic Valve Thrombosis Recommendation for Diagnosis of Bioprosthetic Valve Thrombosis COR LOE Recommendation 2a C-LD 1. In patients with suspected bioprosthetic valve thrombosis, 3D TEE or 4D CT imaging can be useful to rule out leaflet thrombosis.1–5 Synopsis Bioprosthetic valve thrombosis is most common in the first 3 months after implantation but also has been described in patients years (typically 1 or 2) after valve implantation, with the longest interval being 6.5 years.6 Bioprosthetic valves are less thrombogenic than their mechanical counterparts. However, the diagnosis of subclinical bioprosthetic valve thrombosis has increased with use of CT imaging and as a function of the increased numbers of implanted bioprosthetic valves, including TAVI.1–5 Recommendation-Specific Supportive Text 1. Bioprosthetic valve thrombosis appears to be more common with transcatheter than with surgical bioprosthetic valves. Leaflet thrombosis often is suspected on the basis of an increased transvalvular velocity on routine echocardiographic monitoring and can be confirmed by the finding of hypoattenuation of the valve leaflets on CMR imaging. When there is clinical evidence of stenosis, 3D TEE or 4D CT imaging may be useful to detect a layer of valve thrombus, which may respond to treatment with oral anticoagulation. 11.7.2 Medical Therapy Recommendation for Medical Therapy Referenced studies that support the recommendation are summarized in Online Data Supplement 39. COR LOE Recommendation 2a B-NR 1. In patients with suspected or confirmed bioprosthetic valve thrombosis who are hemodynamically stable and have no contraindications to anticoagulation, initial treatment with a VKA is reasonable.1–6 Synopsis Patients with an obstructed bioprosthesis may have a thin layer of thrombus causing reduced leaflet motion. VKA treatment may result in resolution of the thrombus and improvement in valve function. Recommendation-Specific Supportive Text 1. Multiple small nonrandomized studies support the use of VKAs to treat patients with clinical and subclinical bioprosthetic valve thrombosis after both SAVR and TAVI.1,3,4,6,7 VKA anticoagulation can result in a significant reduction of transvalvular gradient, improved leaflet motion, and clinical improvement.4,6,8 Downloaded from http://ahajournals.org by on October 7, 2026