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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 e152 CLINICAL STATEMENTS AND GUIDELINES to the valve, which is not possible with fluoroscopy. When excessive gradients are present with normal leaflet motion and no thrombus, either patient–prosthesis mismatch or pannus formation is present (or both). 3. Stenosis of a bioprosthesis may occur because of progressive structural valve degeneration or pannus formation. However, stenosis can also occur because of a thin layer of thrombus on the valve cusps, which is reversible with oral anticoagulation therapy. Bioprosthetic valves are less thrombogenic than their mechanical counterparts. However, the diagnosis of subclinical bioprosthetic valve thrombosis has increased with the use of CT imaging and as a function of the increased numbers of implanted bioprosthetic valves, including TAVI.3–7 When there is clinical evidence of bioprosthetic valve stenosis, 3D TEE or 4D CT imaging may be useful to detect a layer of valve thrombus as the cause of the obstruction. 11.8.2 Intervention for Prosthetic Valve Stenosis Recommendations for Intervention for Prosthetic Valve Stenosis Referenced studies that support the recommendations are summarized in Online Data Supplement 40. COR LOE Recommendations 1 B-NR 1. In patients with symptomatic severe stenosis of a bioprosthetic or mechanical prosthetic valve, repeat surgical intervention is indicated unless surgical risk is high or prohibitive.1–3 2a B-NR 2. For severely symptomatic patients with bioprosthetic aortic valve stenosis and high or prohibitive surgical risk, a transcatheter ViV procedure is reasonable when performed at a Comprehensive Valve Center.4,5 2a B-NR 3. For patients with significant bioprosthetic valve stenosis attributable to suspected or documented valve thrombosis, oral anticoagulation with a VKA is reasonable.6–13 Synopsis Cumulative survival rates are higher with reoperative AVR than with transcatheter ViV treatment for prosthetic valve stenosis, and a surgical approach is associated with a reduced incidence of patient–prosthesis mismatch, reduced incidence of paravalvular leak, and lower aortic valve gradients.14 The VIVID (Valve-In-Valve International Data) registry examined outcomes with ViV treatment of 459 patients, of whom 40% had isolated stenosis and 30% had mixed lesions.4 Within 1 month after the ViV procedure, 7.6% of patients died and 1.7% had a major stroke. Of the survivors, 93% experienced good functional status (NYHA class I or II), with an overall 1-year survival rate of 83.2%.4 Some systematic reviews comparing outcomes of transcatheter ViV with those of repeat SAVR suggest that hemodynamic outcomes are similar, but stroke and bleeding risks are lower with ViV.15 There is a subset of patients with bioprosthetic valve stenosis attributable to thrombus on the leaflets who may respond to oral anticoagulation with a VKA (Figure 14).6–13 Recommendation-Specific Supportive Text 1. Reoperative surgery for prosthetic valve stenosis is associated with acceptable mortality and morbidity rates in the current era, but the risks are typically higher than those estimated at the time of initial surgery because of older patient age, clinical status at the time of intervention, and reoperative status.2,16 The decision to proceed with surgical versus transcatheter intervention is based on available expertise, individual patient and valve characteristics, and shared decision-making. 2. Catheter-based therapy with transcatheter ViV has emerged as an acceptable alternative to reoperative surgery for the treatment of high– and prohibitive–surgical risk patients with bioprosthetic AS.4,5 Although coronary artery obstruction is more common with aortic ViV procedures than with TAVI for native AS, rates of paravalvular leak and permanent pacemaker implantation are lower with aortic ViV procedures than with TAVI for native AS. Annulus rupture has not been reported. Transcatheter ViV also has been successfully performed for failed surgical bioprostheses in the mitral, pulmonic, and tricuspid positions, although LV outflow obstruction may occur after mitral ViV implantation. 3. A subset of patients presents with stenosis of a bioprosthetic valve attributable to leaflet thrombosis that results in decreased mobility of the leaflets. Leaflet thrombosis can occur from 1 month to years after implantation. If the patient is stable and has no contraindication to long-term anticoagulation, a trial of oral anticoagulation with VKA may result in resolution of the thrombus and improvement in hemodynamics.6–13 However, these patients are at increased risk of recurrent thrombosis (if the anticoagulation is stopped) and early structural deterioration, and thus they require close follow-up.17 11.9 Prosthetic Valve Regurgitation Regurgitation in a mechanical prosthetic valve may be transvalvular, caused by impaired motion of the valve disk secondary to pannus, thrombus, or vegetation interfering with complete closure of the valve occluders, or paravalvular, caused by suture line disruption related to technical error at implantation, suture failure, annular disruption, or endocarditis. Patients with severe mitral annular calcification are particularly vulnerable to developing late paravalvular leak. Regurgitation in bioprosthetic valves may be paravalvular but more often is Downloaded from http://ahajournals.org by on October 7, 2026