Huge Prosthetic Mitral Valve Thrombosis in a Pregnant Woman
A 42-year-old woman in her 30th week of pregnancy who had undergone a mitral valve replacement with a 29-mm St. Jude Medical mechanical prosthetic valve (St. Jude Medical, St. Paul, Minn) 2 years earlier was referred to our hospital with severe dyspnea. She had a history of irregular and subtherapeutic use of enoxaparin 6000 IU/d until admission. Transthoracic echocardiography revealed a mean diastolic mitral transvalvular gradient of 29 mm Hg, mitral valve area of 0.6 cm2, and a giant thrombus with mobile components on the prosthetic valve (Figure 1; online-only Data Supplement Movie I). In spite of the large prosthetic mitral valve thrombosis, she had no history of thromboembolism. Two-dimensional transesophageal echocardiography revealed an unprecedentedly large thrombus (6 cm2 in area) appended to the mitral valve that was restricting the movement of 1 of the leaflets (Figure 2; online-only Data Supplement Movie II). Real-time 3-dimensional transesophageal echocardiography demonstrated restriction of 1 of the leaflets with a thrombus located on the left atrial side of the mitral valve (Figure 3; online-only Data Supplement Movie III). After the patient was given a low-dose (25 mg), slow-infusion (6 hours) tissue plasminogen activator without bolus administration 3 times (for a total of 75 mg), 3-dimensional transesophageal echocardiography showed complete thrombolysis (Figure 4; online-only Data Supplement Movie IV). The mean transprosthetic mitral valve gradient decreased to 4 mm Hg, and mitral valve area increased to 2.7 cm2.
Prosthetic heart valve thrombosis in pregnancy is a life-threatening complication for which management remains controversial. Although review of the literature for management of prosthetic valve thrombosis in a pregnant patient reveals no set guidelines, thrombolytic therapy, thrombectomy, and prosthetic valve replacement are the currently available options. Surgery is usually favored in the current guidelines1 for the management of obstructive prosthetic valve thrombosis; however, the reported operative mortality, depending on the functional class, can be as high as 69%.2 We have reported previously that the high success rate of thrombolysis performed under 2-dimensional transesophageal echocardiographic guidance is independent of valve location and type, morphological characteristics of the prosthetic valve thrombi, and New York Heart Association class at presentation.3 We have also recently shown that a low-dose, slow infusion of tissue plasminogen activator given in discrete successive sessions guided by serial 2-dimensional transesophageal echocardiography is associated with a low risk of complications and a high rate of success even in patients with obstructive thrombosis and New York Heart Association class III or IV.4
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/120/18/e151/DC1.
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