Abstract
Nonbacterial thrombotic endocarditis is frequently diagnosed in postmortem autopsies. However, in some patients with systemic diseases it is diagnosed in the context of multiple embolic events, so a high degree of clinical suspicion must be maintained to offer the best treatment to these patients.
We report a case of a 59-year-old woman with diagnosis of stage IV lung adenocarcinoma in the context of first episode of cardiac tamponade requiring urgent pericardiocentesis.
She was admitted to the emergency department for an acute ischemic stroke, so antiplatelet therapy was started and chemotherapy discontinued. After few weeks, she required new admission due to progression of the oncological disease and bilateral pulmonary thromboembolism secondary to deep vein thrombosis of the lower extremities. Given the progression of the disease, it was decided not to return to chemotherapy and to start anticoagulant therapy with low molecular weight heparin.
A transthoracic echocardiogram (TTE) was requested, which highlighted a thickened mitral valve with severe mitral regurgitation, not present in the TTE performed one year before. She was asymptomatic, without fever, with repeatedly negative blood cultures and absence of infectious markers. A new TTE was repeated 4 weeks later, beeing under antiplatelet and anticoagulant treatment, observing a greater thickening of both mitral leaflets with nodular image on the anterior mitral leaflet, persisting a severe mitral regurgitation. Given the low probability of infective endocarditis, these findings were attributed to a nonbacterial thrombotic endocarditis in the context of a progressive malignant disease.
Nonbacterial thrombotic endocarditis is characterized by the presence of sterile vegetations formed by the accumulation of platelets and fibrin. It is associated with neoplastic processes (specially with mucinous adenocarcinomas) as well as with autoimmune, rheumatologic and infectious processes.
These vegetations tend to produce multiple systemic embolizations, which usually manifests as the first symptom. Patients do not usually present murmurs in the physical examination, nor fever, and blood cultures are negative. It is necessary to complete the study with a TTE, where the left valves tend to be affected more frequently (mitral valve in 2/3 of the cases). In case of doubt, the study should be completed with a TEE, although neither of these techniques differentiates infectious vegetations from thrombotic ones.
Treatment consists of treating the underlying cause and starting anticoagulation with heparin to prevent new embolisms. In some isolated cases the surgical treatment of this entity has been proposed.
Conclusion
presence of nonbacterial thrombotic endocarditis should be suspected in all patients with multiple embolisms and concomitant systemic disease. Study must be completed with a TTE/TEE and anticoagulant treatment should be started.
Abstract P691 Figure. A: Mitral valve 1 year before. B: now
Recurrent Mitral Valve Endocarditis Caused byStreptococcus pneumoniaein a Splenectomized Host