Makindo Medical Notes

Marantic endocarditis, also known as non-bacterial thrombotic endocarditis (NBTE), is characterized by sterile platelet-fibrin vegetations on heart valves. It is often associated with disseminated malignancy and reflects an advanced, hypercoagulable state.

About

• Marantic endocarditis typically occurs in the context of systemic malignancies, particularly those that create a hypercoagulable environment.

Causes

• Solid Tumors: Commonly adenocarcinomas (e.g., pancreatic cancer, gastric cancer) are implicated.
• Hematologic Malignancies: Conditions such as acute promyelocytic leukemia can also be associated.

Pathology

• Sterile fibrin and platelet vegetations form along the lines of valve closure without an underlying infectious etiology.
• The vegetations tend to be small, friable, and can easily dislodge, leading to systemic embolization.

Clinical Features

• Murmurs: Valvular vegetations may alter normal blood flow, producing characteristic heart murmurs.
• Embolic Phenomena: Fragmentation of vegetations can cause emboli to various organs, potentially leading to infarcts or ischemic events (e.g., stroke, renal or splenic infarcts).
• Heart Failure: Significant valvular dysfunction may eventually compromise cardiac output and contribute to heart failure symptoms.

Investigations

• Blood Tests:
  • Full Blood Count (FBC) may show anaemia of chronic disease.
  • Inflammatory markers such as CRP and ESR are often elevated due to the underlying malignancy and systemic inflammation.
• Blood Cultures: Typically sterile, helping differentiate NBTE from infective endocarditis.
• Echocardiography: Can reveal valvular vegetations and possible valve destruction or regurgitation. Transesophageal echocardiography (TEE) may provide better visualization.
• ECG: May show non-specific abnormalities related to underlying cardiac strain or embolic complications but is not diagnostic of NBTE.

Management

• Palliative Approach: Management focuses on controlling the underlying malignancy and providing symptomatic relief. Anticoagulation may be considered to reduce embolic risk.
• Surgical Intervention: Valve replacement is rarely pursued given the advanced stage of underlying disease and overall poor prognosis.