🫀 Marantic endocarditis (non-bacterial thrombotic endocarditis, NBTE) is defined by sterile platelet–fibrin vegetations on cardiac valves.
⚖️ Strongly linked to a hypercoagulable state, especially in advanced malignancy.
🚑 Clinical significance often lies in recurrent systemic emboli rather than valve destruction.
ℹ️ About
- Occurs mainly in patients with advanced cancer (especially adenocarcinoma) or chronic debilitating disease.
- Represents part of the Trousseau syndrome spectrum of malignancy-associated thrombosis.
🧬 Causes
- Solid Tumors: Pancreatic, gastric, and lung adenocarcinomas are most common.
- Hematologic Malignancies: Leukemias (e.g., acute promyelocytic leukemia).
- Other States: Severe sepsis, systemic lupus erythematosus (Libman–Sacks overlap), chronic wasting disease.
🔬 Pathology
- Small, friable, sterile vegetations along valve closure lines (most often mitral and aortic valves).
- Histology shows fibrin + platelet aggregates without inflammatory cells or organisms.
- Vegetations embolize easily → systemic infarcts (brain, spleen, kidneys).
🩺 Clinical Features
- Murmur: Often subtle, sometimes absent, as vegetations are small.
- Embolic Phenomena: Ischemic stroke 🧠, renal infarcts 🧽, splenic infarcts 🍐, digital ischemia.
- Heart Failure: Rare, unless vegetations cause significant valve regurgitation.
🧪 Investigations
- Blood Tests:
- FBC → anaemia of chronic disease.
- Raised ESR/CRP due to underlying malignancy.
- Blood Cultures: Sterile ❌ (contrast with infective endocarditis).
- Echocardiography: TTE/TEE may detect small vegetations; TEE is more sensitive.
- ECG: Non-specific; may show changes if embolic MI or atrial fibrillation complicates course.
💊 Management
- Anticoagulation: Heparin (LMWH preferred over warfarin) may reduce embolic risk. Warfarin less effective in malignancy-associated thrombosis.
- Oncology Treatment: Treating the underlying malignancy is the only definitive strategy.
- Palliative Approach: Supportive care often appropriate due to poor prognosis.
- Surgery: Rare; valve replacement considered only if embolic risk is extreme and life expectancy otherwise reasonable.
📚 Exam Tips:
👉 NBTE = malignancy + sterile vegetations + recurrent emboli.
👉 Differentiate from infective endocarditis: sterile cultures, lack of fever/systemic infection.
👉 Think “stroke in a cancer patient” → always consider NBTE.
