A 75-year-old woman with a history of failed surgical mitral valve repair presented with severe symptomatic mitral regurgitation (MR) and underwent surgical mitral valve replacement (MVR) with a 25-mm Carpentier-Edwards Perimount Magna (Edwards Lifesciences; Irvine, CA) bovine bioprosthesis.
The patient presented 2 years later with severe progressive dyspnea on exertion. Diuretics afforded her only minimal relief. Cardiac catheterization revealed angiographically normal coronaries, moderate pulmonary hypertension (pulmonary artery pressures 50/27(35) mmHg), and markedly elevated pulmonary artery wedge pressure (33 mmHg). Three-dimensional (3D) transesophageal echocardiography (TEE) demonstrated severe stenosis of the mitral bioprosthesis (mitral valve area of 0.6 cm2 by 3D planimetry) (Video 1) secondary to commissural fusion, as well as mild transvalvular MR. Left ventricular systolic function remained normal.
Because the patient was deemed to be at high risk for repeat surgical MVRwith morbidity or mortality estimated to be 38% using the Society of Thoracic Surgeons (STS) calculatoran alternative approach was sought. She underwent percutaneous mitral balloon valvuloplasty (PMBV) (Video 2). PMBV produced a 2.5-fold increase in the mitral valve area to 1.5 cm2 by 3D TEE planimetry and a decrease in mean mitral valve gradient from 16 mmHg to 6 mmHg.
The patient experienced a dramatic improvement in her symptoms. However, she returned 2 years later with recurrent profound dyspnea and was found to have severe restenosis of her bioprosthetic mitral valve (mitral valve area of 0.8 cm2).
Which intervention is most appropriate for this patient at this time?
The correct answer is: C. Perform percutaneous mitral valve-in-valve implantation
A. Surgical MVR
The patient has numerous risk factorsincluding advanced age, female sex, prior valve surgery, and severe mitral stenosisthat together make her a poor surgical candidate. Her STS score for MVR estimated an 11% risk of operative mortality and a 38% cumulative risk of operative morbidity or mortality.
B. Repeat PMBV
Although PMBV is the treatment of choice for native MV stenosis due to commissural fusion, data for this treatment of bioprosthetic MV stenosis are limited, so its safety and efficacy remain uncertain. Because bioprosthetic valve stenosis is often due to cusp fibrosis and calcification rather than commissural fusion, PMBV may cause cuspal fractures or dislodgment of calcific debris that lead to significant MR or embolic phenomena.1 Nevertheless, several case reports do suggest a role for PMBV in specifically selected patients who are high risk for both open surgical MVR and the increasingly available technique of percutaneous valve-in-valve implantation.2-4 Our patient initially underwent PMBV because no other surgical or percutaneous option was available at the time.
C. Percutaneous Mitral Valve-in-Valve Implantation
Percutaneous valve-in-valve replacement was initially developed to treat bioprosthetic aortic valve failure. In 2009, Cheung and colleagues reported its first use for mitral bioprosthesis dysfunction.5 Since then, it has become an attractive option for patients with severe symptoms who are poor surgical candidates.6 A recent retrospective analysis of 121 patients with degenerated mitral bioprostheses who had undergone either open surgical or percutaneous MVR indicated that patients whose valve replacements were performed using the transcatheter approach were indeed older and had significantly higher STS scores.7 The procedure time, intensive care time, and post-procedure length of stay were all shorter in the group that received percutaneous intervention. Mitral valve pressure gradients and severity of MR were similar in both groups at 30 days, with slightly higher pressure gradients but no difference in MR reported in the percutaneous group at 1 year. Mortality in the two groups was equivalent at 1 year. These data are encouraging, but larger, randomized studies with longer-term follow-up are still needed to rigorously validate the efficacy of the transcatheter approach.
Our patient underwent percutaneous mitral valve-in-valve replacement with a 26-mm Edwards SAPIEN XT (Edwards Lifesciences; Irvine, CA) valve deployed within her 25-mm Carpentier-Edwards Perimount Magna bioprosthesis (Video 3). Her mitral valve gradient immediately post-procedure was 2 mmHg, and her periprocedural course was uncomplicated. One year later, the gradient had increased slightly to 8 mmHg, consistent with recurrent mitral stenosis. But it has remained stable, and the patient has continued to feel well in the ensuing 4 years.8
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Cheung A, Webb JG, Barbanti M, et al. 5-year experience with transcatheter transapical mitral valve-in-valve implantation for bioprosthetic valve dysfunction. J Am Coll Cardiol 2013;61:1759-66.
Kamioka N, Babaliaros V, Morse MA, et al. Comparison of Clinical and Echocardiographic Outcomes After Surgical Redo Mitral Valve Replacement and Transcatheter Mitral Valve-in-Valve Therapy. JACC Cardiovasc Interv 2018;11:1131-8.
Vainrib AF, Moses MJ, Benenstein RJ, et al. Multimodality Imaging of Bioprosthetic Percutaneous Balloon Valvuloplasty Followed by Valve-in-Valve Implantation for Mitral Stenosis Due to Commissural Leaflet Fusion. JACC Cardiovasc Interv 2016;9:e43-e45.