🫀 Cardio Question: Empiric Antibiotics in Prosthetic Valve IE

🫀 Cardio Question: Empiric Antibiotics in Prosthetic Valve IE

A 65-year-old man with a mechanical mitral valve presents with fevers, night sweats, and malaise. Blood cultures are pending. He had his valve placed 4 months ago. TEE reveals a vegetation on the prosthetic mitral valve.

Which of the following is the most appropriate empiric antibiotic regimen?

A) Vancomycin + Gentamicin
B) Vancomycin + Cefepime + Rifampin
C) Ampicillin + Ceftriaxone
D) Vancomycin + Piperacillin-Tazobactam
E) Linezolid + Ceftriaxone + Gentamicin

✅ B) Vancomycin + Cefepime + Rifampin

🧠 Here's Why:

This is early-onset prosthetic valve endocarditis (PVE) — occurring within 12 months of valve replacement.

💣 In early PVE, we worry about:

• Staph aureus (MSSA/MRSA)

• Staph epidermidis (coag-neg Staph)

• Gram-negatives (e.g. Pseudomonas)

• Fungal

• Resistant organisms from the OR

🔬 Empiric regimen must cover:

• MRSA → Vancomycin

• Gram-negative rods (including Pseudomonas) → Cefepime

• Biofilm on prosthetic material → Rifampin (excellent penetration + synergy)

💡 Key PVE Rules:

Why not the others?

• A) Vanc + gent = native valve, not broad enough for early PVE

• C) Amp + ceftriaxone = good for enterococcus, not prosthetic valve empiric tx

• D) Vanc + pip-tazo = OK for sepsis, not prosthetic valve IE (no rifampin)

• E) Linezolid = not first-line and doesn't replace vanc for IE