A 75-year-old man with a prosthetic mitral valve develops fever, new regurgitant murmur, and multiple cerebral emboli 2 months post-implantation. Blood cultures grow coagulase-negative Staphylococci. The most likely type of prosthetic valve endocarditis is:
- A Early prosthetic valve endocarditis (<60 days post-surgery), caused by intraoperative/perioperative contamination by nosocomial organisms ✓
- B Late prosthetic valve endocarditis (>12 months), usually caused by Streptococcus viridans
- C Non-bacterial thrombotic endocarditis on the prosthetic ring
- D Libman-Sacks endocarditis from underlying antiphospholipid syndrome
Correct answer: A. Early prosthetic valve endocarditis (<60 days post-surgery), caused by intraoperative/perioperative contamination by nosocomial organisms
Explanation
Prosthetic valve endocarditis (PVE) occurring within 60 days of surgery (early PVE) is caused by intraoperative inoculation or perioperative bacteremia with nosocomial organisms — primarily coagulase-negative staphylococci (CoNS, particularly S. epidermidis), S. aureus, Gram-negative bacilli, and fungi. The infection typically involves the sewing ring (ring abscess), rather than leaflets, and can cause dehiscence. Late PVE (>12 months) has a microbiology similar to native valve IE, with Streptococcus viridans predominating, acquired via dental or GI procedures.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.