Quadrivalvular marantic endocarditis (ME) mimicking acute bacterial endocarditis (ABE)

Area of Science:

• Cardiology
• Pathology
• Internal Medicine

Background:

• Marantic endocarditis (ME) is characterized by noninfectious vegetations on heart valves.
• Commonly associated conditions include malignancy, hypercoagulable states, post-instrumentation, prior infective endocarditis (IE), renal insufficiency, burns, and systemic lupus erythematosus (Libman-Sacks endocarditis).
• ME requires differentiation from IE due to overlapping clinical presentations like fever, heart murmur, and embolic phenomena.

Observation:

• The case presented involves quadrivalvular ME with massive vegetations affecting all cardiac valves, aorta, atria, and pulmonary artery.
• ME can mimic acute bacterial endocarditis (ABE), presenting with similar symptoms.
• Diagnostic challenges arise as both conditions share clinical features.

Findings:

• Infective endocarditis (IE) is typically suggested by leukocytosis and elevated erythrocyte sedimentation rate.
• The hallmark of IE is cardiac vegetation coupled with continuous high-grade bacteremia.
• Absence of bacteremia, after excluding causes of culture-negative endocarditis, is key to differentiating ME from IE.

Implications:

• Accurate differentiation between ME and IE is critical for appropriate patient management and treatment strategies.
• This case underscores the importance of considering ME in the differential diagnosis of endocarditis, especially in culture-negative scenarios.
• The extensive nature of vegetations in this reported case provides valuable insights into the potential severity and presentation of ME.