Nonbacterial thrombotic endocarditis (NBTE) is a rare clinical condition characterized by the presence of sterile vegetations on valvular leaflets Gross and Friedberg (1936). The most frequent cause of NBTE is antiphospholipid syndrome Hughson and et al. (1993); malignancy, through an intrinsic condition of hypercoagulability, is the second most common cause Thomas (2001). Systemic thromboembolic complications are frequently associated with this condition, but coronary embolism is not common. We report the case of a patient with NBTE secondary to gastric adenocarcinoma with clinical symptoms of coronary and systemic emboli.
A 43-year-old previously healthy woman presented with sudden onset of substernal chest pain that had begun some hours earlier. She had no history of coronary artery disease. Physical examination revealed pulse 98 beats/min and blood pressure 95/60 mm, Hg. Electrocardiogram (ECG) showed ST segment elevation in leads II, III, AVF (Figure
Ecg on admission reveals ST segment elevation in leads II, III, AVF.
Transesophageal echocardiography shows an echodense structure (0.7 cm by 1 cm) on the atrial aspect of the anterior mitral leaflet.
Consequently, the patient was promptly scheduled for a gastrectomy but suddenly developed a right-sided facial droop and further visual disturbances. A second TEE demonstrated persistence and enlargement of the two vegetations previously seen on the mitral leaflets, in spite of the anticoagulant therapy which had been promptly started. Therefore priority was given to valvular surgery and the patient underwent mitral valve replacement with a bioprostheses without complications. At surgery, the echocardiographic preoperative findings were confirmed (Figure
Arrows point to the vegetations on the leaflets.
NBTE is characterized by the formation of vegetations on heart valves in the absence of systemic bacterial infections. The vegetations are made up of fibrin and blood platelets and the valvular tissue is either normal or shows some evidence of inflammatory response. As to the pathogenesis, it has been suggested that NBTE could result from local valvular damage mediated by elevated levels of circulating cytokines (such as tumor necrosis factor or interleukin-1). It may also result from the well-known hypercoagulable state associated with malignancies (increased levels of factor VIII, fibrinogen, and von Willebrand factor) [
The incidence of NBTE is uncertain. However, in three large autopsy series published over the last 30 years [
The major clinical manifestations of NBTE result from systemic emboli rather than valvular dysfunction. In the great majority of these patients an embolism occur specially in the spleen, the kidneys, or the central nervous system [
Treatment of NBTE includes systemic anticoagulation to prevent recurrent thromboembolism. However, in patients with malignancy-related NBTE, warfarin is often ineffective, probably because of the presence of some nonvitamin K-dependent procoagulant agents which relate to the underlying neoplasm [
The indications and appropriate timing of surgical therapy in NBTE have not been formally evaluated. However, in patients with cancers that are potentially curable, the recurrence of embolic events despite anticoagulation and the presence of valvular dysfunction could suggest the need to give priority to the cardiac procedure.
In the case reported, clinical presentation was unusual: at the onset, embolism first affected coronary circulation, with electrocardiographic and clinical signs of acute inferior myocardial infarction, and later central nervous system. On the basis of the recurrent embolic events registered (despite a correct anticoagulant therapy) and given that the underlying gastric cancer was considered curable, a preliminary valvular surgery seemed advisable.