Nonbacterial Thrombotic Endocarditis: Presentation, Pathophysiology, Diagnosis and Management

Non-bacterial thrombotic endocarditis: a clinical and pathophysiological reappraisal

Non-bacterial thrombotic endocarditis (NBTE), formerly recognized as marantic endocarditis, represents a rare cardiovascular pathology intricately linked with hypercoagulable states, notably malignancy and autoimmune disorders. Characterized by the development of sterile vegetations comprised of fibrin and platelets on cardiac valves, NBTE poses a diagnostic challenge due to its resemblance to infective endocarditis. Therapeutic endeavours primarily revolve around addressing the underlying aetiology and instituting anticoagulant regimens to forestall embolic events, with surgical intervention seldom warranted. Non-bacterial thrombotic endocarditis frequently coexists with malignancies and autoimmune conditions, such as lupus and antiphospholipid antibody syndrome, and, more recently, has been associated with COVID-19. Its pathogenesis is underpinned by a complex interplay of endothelial dysfunction, hypercoagulability, hypoxia, and immune complex deposition. Clinical manifestations typically manifest as embolic phenomena, particularly cerebrovascular accidents, bearing substantial mortality rates. Diagnosis necessitates a high index of suspicion and meticulous exclusion of infective endocarditis, often facilitated by advanced cardiac imaging modalities. Anticoagulation, typically employing low molecular weight heparin or warfarin, constitutes the cornerstone of pharmacological intervention. Surgical recourse may be warranted in instances of refractory heart failure or recurrent embolic events. Given its multifaceted nature, the management of NBTE mandates a multidisciplinary approach, with prognosis contingent upon individual clinical intricacies. Future endeavours should prioritize further research to refine therapeutic strategies and enhance patient outcomes.

Nonbacterial thrombotic endocarditis of mitral valve associated with a lymphoproliferative malignancy: case report and literature review

BACKGROUND

Non-bacterial thrombotic endocarditis (NBTE) is a rare condition marked by sterile vegetations on cardiac valves, often linked to rheumatologic diseases, autoimmune disorders, and advanced solid malignancies. An early diagnosis and treatment of the associated clinical condition are mandatory, although they do not usually eliminate valvular vegetations, making anticoagulation essential to prevent embolic events. Despite variability, the prognosis of NBTE is usually unfavorable due to recurrent embolic events and the severity of the primary condition, typically advanced cancer.

CASE PRESENTATION

We present a case of a 57 years-old male who presented to the emergency department with a 5-day history of painful bilateral digital edema and color change episodes (from pallor to cyanosis). Physical examination revealed erythrocyanosis in the distal extremities, prompting consideration of secondary Raynaud syndrome. Despite medical therapy, progressive digital ischemia led to multiple finger amputations. During etiological investigation, anticoagulation tests and autoimmune analysis yielded negative results. A transesophageal echocardiogram was performed, revealing an irregular hyperechogenic mass on the anterior leaflet of the mitral valve without valve dysfunction, and a thoracic computed tomography scan with contrast showed an enlarged right paratracheal lymph node. Histopathological analysis from a transthoracic needle biopsy of the paratracheal lymph node revealed diffuse large B-cell lymphoma. The patient underwent aggressive R-CHOP chemotherapy, achieving a favorable complete response.

CONCLUSION

This is a particular case involving the occurrence of NBTE and Raynaud phenomenon as the initial paraneoplastic manifestations in a previously healthy young man. Reports of NBTE associated with lymphoproliferative conditions are quite rare, with fewer than ten cases described in the literature. To our knowledge, this is the first case of NBTE specifically associated with diffuse large B-cell lymphoma.

Unveiling Lung Adenocarcinoma: Non-bacterial Thrombotic Endocarditis as the Debut Sign

Non-bacterial thrombotic endocarditis (NBTE) involves the deposition of fibrin and platelets on heart valves, frequently leading to systemic embolism. The association between NBTE and cancer demands thorough investigation in cases lacking an evident cause. This case report elucidates the clinical course of a nonsmoking woman in her sixties with NBTE linked to pulmonary adenocarcinoma. The patient, who had a history of multiple sclerosis (MS) and was receiving dimethyl fumarate treatment, presented to the emergency department with stroke-like symptoms. Diagnostic challenges arose due to preexisting motor sensory impairment from MS. Initial evaluations revealed hypocapnia and elevated inflammatory markers. Blood cultures were obtained twice, and imaging confirmed pneumonia, left pleural effusion, and chronic pulmonary embolism while excluding acute vascular events or intracranial hemorrhage. The first transthoracic echocardiogram (TTE) indicated no cardiac abnormalities. Treatment encompassed parenteral antibiotics, systemic anticoagulation, and admission to medical floors. Although the initial treatment yielded a positive clinical response, subsequent complications emerged. On the tenth day, the patient required additional interventions, including broad-spectrum antibiotics and supplemental oxygen. A follow-up chest X-ray revealed persistent pneumonia and pleural effusion, and blood cultures upon admission returned negative. A subsequent head MRI confirmed an embolic stroke and displayed evidence of MS progression. Around the twentieth day, empirical treatment for infective endocarditis was initiated, and an 8 mm vegetation on the aortic valve was identified via transesophageal echocardiography (TOE). Acute pulmonary edema prompted a transfer to the intermediate care unit. Further investigations, including left thoracocentesis and CT, unveiled exudate and metastatic lesions in the liver, ilium, and kidney. Unfortunately, on the twenty-fifth day, the patient experienced acute myocardial infarction, right leg ischemia, disseminated intravascular coagulation, and shock. Pleural fluid analysis revealed malignant cells suggestive of lung adenocarcinoma. This case underscores the pivotal role of timely NBTE recognition and the search for malignancy when workup for infective endocarditis and autoimmune panels is negative. Moreover, it emphasizes the significance of vigilant monitoring, particularly in immunocompromised individuals or those with preexisting neurological deficits, especially when new neurological symptoms manifest. These insights significantly contribute to the comprehension of NBTE management and its implications for analogous patient cohorts.

Case report: New is not always better: treatment of non-bacterial thrombotic endocarditis

An elderly female with metastatic adenocarcinoma of the lung and atrial fibrillation presented with multiple embolic strokes while on anticoagulation with Apixaban. After further investigation, a TEE showed lesions of non-bacterial thrombotic endocarditis on the mitral valve. A decision to switch the patient to LMWH for anticoagulation was then made and a follow-up TEE showed resolution of the NBTE. In this abstract, we show that heparin should remain as the anticoagulation agent of choice in the setting of NBTE associated with malignancy.