抗リン脂質抗体症候群に起因する非細菌性血栓性心内膜炎の1例

Nonbacterial Thrombotic Endocarditis Caused by Antiphospholipid Antibody Syndrome：Report of a Case

はじめに　非細菌性血栓性心内膜炎（nonbacterial thrombotic endocarditis：NBTE）では，自己免疫疾患や悪性腫瘍に限らず，心内膜障害をきたすさまざまな病態により，主に僧帽弁や大動脈弁に血小板とフィブリンからなる疣贅が形成される1）．治療法は原疾患の治療と抗凝固療法であるが2），弁膜変化から心不全をきたす症例や再発する塞栓症例では手術を考慮する．

A 73-year-old woman with multiple episodes of cerebral infarction was diagnosed with nonbacterial thrombotic endocarditis （NBTE） and antiphospholipid antibody syndrome. Transesophageal echocardiography revealed highly mobile tumors both in the mitral and the aortic valve, and the patient underwent aortic and mitral valve replacement. Pathologically, tumor of the mitral valve was a thrombus, and that of the aortic valve was a papillary fibroelastoma. Early after surgery, a recurrent thrombus was found in the left atrium, but no organ embolization ensued, and the patient had no adverse event for six months thereafter. Surgery is indicated only in limited cases of NBTE, because postoperative anticoagulation therapy is hard to manage and clinical outcome is poor.