A Rare Case of Tricuspid Endocarditis

Christopher H. Girgis M.D and Carmen Vesbianu M.D.

June 25, 2018

A 54-year-old Caucasian woman presented with fever, chills and worsening dyspnea for one month. Her past medical history included tricuspid endocarditis in 2009 and 2012. In 2009, she was diagnosed with culture-negative endocarditis, and a bioprosthetic tricuspid valve replacement was performed due to severe tricuspid regurgitation and symptoms of right heart failure. Notably, she received antibiotics prior to obtaining blood cultures. In 2012, she was diagnosed with endocarditis of the bioprosthetic tricuspid valve. Blood cultures grew Pseudomonas aeruginosa. She underwent a second tricuspid valve replacement, also due to symptomatic right heart failure.  

She did well for the next four years until she developed the symptoms at current presentation. She denied recent intravenous (IV) drug abuse, although she had a history of previous use many decades prior.  She lived near farms, but denied direct contact with animals other than her two pet dogs. She denied unpasteurized milk or undercooked meat consumption. She reported a two-day antibiotic treatment one month prior to her admission.

On physical exam, blood pressure was 126/73 mmHg, heart rate was 93 beats per minute, oxygen saturation was 90% on room air and temperature was 37.1°C. Her exam was notable for bilateral pulmonary crackles and a +4/6 holosystolic murmur that was heard at the left sternal border. She had positive jugular venous distension and bilateral pitting edema of the lower extremities, extending to the knees. She had a distended abdomen with dullness on percussion over the flanks and tympany over the umbilicus. No track marks were observed.

A transesophageal echocardiogram was performed and revealed three mobile masses on the tricuspid valve measuring 1.8 x 1.0 cm, 1.0 x 0.9 cm, 1.1 x 0.5 cm associated with moderate to severe tricuspid regurgitation (Figure 1). Three sets of blood cultures remained negative after 5 days. HIV testing was negative. Hepatitis C antibodies were positive with a high viral load. Urine drug screen was positive for cannabinoids.

Figure 1: transesophageal echocardiogram apical four chamber view demonstrating large vegetations on the tricuspid valve

MCQ 1: Which one of the following is the least likely reason for the negative blood cultures in this patient with prosthetic tricuspid endocarditis?

1. Fastidious organisms like Coxiella, Bartonella, Brucella
2. HACEK organisms
3. Previous antibacterial treatment
4. Nonbacterial thrombotic endocarditis

MCQ 2: What is the most appropriate management for this patient?

1. Treat with IV antibiotics
2. Start anticoagulation
3. Treat with IV antibiotics and perform valve replacement
4. Valve replacement alone

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