2018 Volume 82 Issue 8 Pages 2210-2211
An 80-year-old woman was admitted with acute heart failure to the Department of Acute Cardiology, National Institute of Cardiovascular Diseases, Slovakia. Seven years before the admission, she had undergone coronary artery bypass grafting surgery and mitral annuloplasty with semi-rigid St. Jude Seguin ring, N.30 (Figure A). Seven months before the present admission she had undergone simultaneous transapical, transcatheter aortic valve and mitral valve-in-ring implantation with Edwards Sapien 3, N.23 and Edwards Sapien XT, N.29, respectively (Figure B,C) due to severe, symptomatic aortic stenosis, recurrent mitral regurgitation and high risk for surgery. The procedure was successful with a mean, mitral pressure gradient of 6 mmHg, left atrial (LA) diameter of 53 mm and a grade I spontaneous echo contrast. The cardiosurgeon advised warfarin for 6 months after the procedure with a target international normalized ratio (INR) of 2–3 and acetylsalicylate acid lifelong. According to the recommendation, the patient stopped the warfarin after 6 months and for 3 weeks she was on the acetylsalicylate acid with subsequent rapid onset of orthopnea and intermittent, retrosternal chest pain occurring at rest. Acute heart failure was diagnosed. Transthoracic echocardiography showed severe mitral stenosis with a mean pressure gradient of 16 mmHg and a dilated LA to 55 mm with a grade II spontaneous echo contrast. I.v. loop diuretics were given with good clinical effect. Subsequent transesophageal echocardiography (TEE) showed an oval formation 11×10 mm on the lateral side of the mitral prosthesis (Figure D, asterisk). The 3-D TEE showed a rigid motion of a sole thickened cusp, free of calcification, with a smooth atrial side (Figure E,F; Movie S1). Based on its appearance and acute symptom onset, thrombus was suspected and unfractionated heparin was started empirically as a bridge to warfarin with a target INR 3–3.5. Ten days later the mean mitral pressure gradient decreased to 9 mmHg. The patient was discharged symptomless with target INR 2–3. Control TEE after 3 weeks showed mobile cusps, free of thrombus and with a baseline mean, mitral pressure gradient of 6 mmHg (Figure G–I; Movie S2).
(A) 3D transesophageal echocardiography of the semi-rigid St. Jude Seguin mitral ring. (B) Guide wire in the mitral ring imaged with the 3D transesophageal echocardiography. (C) Placement of the transcatheter mitral valve in the mitral ring. (D) Oval formation in the lateral side of the mitral prosthesis depicted with the red asterisk. (E) Thrombotic, transcatheter mitral valve prosthesis – closed. (F) Thrombotic transcatheter mitral valve prosthesis with the rigid cusp – opened. (G) Resolution of the thrombus. (H) Transcatheter mitral valve prosthesis after anticoagulation – closed. (I) Transcatheter mitral valve prosthesis after anticoagulation – opened.
The key question in this case was whether the prosthetic mitral valve dysfunction was due to an early pannus-valve degeneration or to thrombosis. There are several distinguishing characteristics in the differential diagnosis of pannus and thrombus. Pannus is usually formed around the aortic prosthesis whereas thrombus is usually attached to the mitral prosthesis. If pannus is formed around the mitral prosthesis, it is usually embedded in the atrial side, in comparison with the ventricular location of thrombus. Another characteristic of pannus is that the annular shape and symptoms caused by the valve dysfunction are chronic in nature. A thrombotic prosthetic complication is usually related to anticoagulation therapy withdrawal or inefficiency, with acute onset of symptoms.1,2 These criteria helped considerably in determining the correct diagnosis. Furthermore, we showed that 3-D TEE is useful in diagnosing the etiology of transcatheter prosthetic valve dysfunction.
Due to lack of data, the optimal anti-thrombotic therapy after this kind of procedure is unknown. Due, however, to the combination of slow flow in the mitral position and the anatomy of the mitral prosthesis with a prominent frame into the left ventricle, the prothrombotic potential of transcatheter mitral valve prosthesis might be greater than that of transcatheter aortic valve prosthesis, and coagulation factors might have a bigger impact on thrombus formation than platelet aggregation. As a consequence, anticoagulation therapy might be used.3 The optimal duration of anticoagulation is challenging but when other risk factors such as dilated LA and spontaneous echo contrast are present, warfarin with INR 2–3 might be maintained in the long term.4
The authors declare no conflict of interest.
Supplementary File 1
Movie S1. Thrombosis of the mitral valve prosthesis with a rigid motion of one cusp.
Supplementary File 2
Movie S2. Mitral valve prosthesis after the anticoagulation with mobile cusps.
Please find supplementary file(s);
http://dx.doi.org/10.1253/circj.CJ-17-0740
