Correspondence

Nonbacterial Thrombotic Endocarditis in Three Members of a Family

N Engl J Med 1997; 336:1677-1678June 5, 1997

Article

To the Editor:

Nonbacterial thrombotic endocarditis is a rare clinical entity whose cause is poorly understood.1-4 We describe a father and his two daughters who had this disorder and associated cerebral embolic strokes.

A 34-year-old, previously healthy woman who was 27 weeks pregnant presented with sudden left-sided facial and upper-body weakness. She reported no history of neurologic diseases, other medical illnesses, or intravenous drug use. Magnetic resonance imaging of the brain showed an ischemic lesion in the right insular and low frontal territories due to occlusion of the right middle cerebral artery, with no evidence of hemorrhage, masses, or cortical venous thrombosis. Multiple blood and urine cultures were negative, as were tests for autoimmune diseases and hypercoagulable states. Doppler studies of the lower extremities and carotid ultrasonography were normal.

Two transthoracic echocardiograms were normal, but a transesophageal echocardiogram showed several small, oscillating masses 9 mm in length at the commissural level of both the anterior and the posterior mitral-valve leaflet (Figure 1Figure 1Transesophageal Echocardiogram of the Mitral Valve in the Longitudinal Plane, Showing Small Vegetations (Arrow) on the Anterior and Posterior Leaflets.). Intravenous heparin was given for the remainder of the pregnancy and puerperium, with nearly complete recovery.

A healthy female infant was delivered vaginally at term, and the mother was started on warfarin therapy. Two weeks post partum, anticoagulant treatment was interrupted because of vaginal bleeding. Another stroke with a new lesion in the left parietal cortex occurred, which prompted the reinstitution of warfarin. The patient has remained asymptomatic for 12 months.

The patient's father had 10 embolic strokes, the first at the age of 27. At the age of 40, he died after an acute, massive myocardial infarction caused by embolism from aortic-valve vegetations. Left-sided hemiparesis developed suddenly in the patient's sister at the age of 36. Cerebral imaging showed a new infarct in the territory of the right middle cerebral artery and evidence of numerous older infarcts. An echocardiogram identified a large vegetation on the mitral valve. Neither the father nor the sister had clinical evidence of infective endocarditis. The patient's brother underwent surveillance echocardiography that showed a bicuspid aortic valve and thickening of the mitral-valve leaflet. No cancers were diagnosed in the patients studied.

The familial aggregation of nonbacterial thrombotic endocarditis with associated cerebral embolic events suggests that a genetic predisposition to the valvular endocardial structural abnormalities may play a part in the pathogenesis of the disorder in this family.

Karen L. Leung, M.D.
Dianna M. Milewicz, M.D., Ph.D.
Martin D. Phillips, M.D.
Eddy Barasch, M.D.
University of Texas–Houston Medical School, Houston, TX 77030

4 References

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   Lopez JA, Ross RS, Fishbein MC, Siegel RJ. Nonbacterial thrombotic endocarditis: a review. Am Heart J 1987;113:773-784
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   Rogers LR, Cho ES, Kempin S, Posner JB. Cerebral infarction for non-bacterial thrombotic endocarditis: clinical and pathological study involving the effects of anticoagulation. Am J Med 1987;83:746-756
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   Tsanaclis AM, Robert F. Cerebral embolism in nonbacterial thrombotic endocarditis associated with carcinoma: a clinico-pathological study. Acta Neurol Latinoam 1976;22:86-103
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