Management of Prosthetic Valve Endocarditis

General Management Principles

The American College of Cardiology recommends that prosthetic valve endocarditis (PVE) be treated with aggressive combination antimicrobial therapy for a minimum of 6 weeks plus early surgical intervention in most cases, with treatment decisions made by a multispecialty Heart Valve Team (cardiology, cardiothoracic surgery, infectious disease). 1
The American Heart Association advises that the duration of antibiotic therapy be counted from the first day that blood cultures become negative, not from the start of treatment. 8
Blood cultures should be obtained every 24–48 hours until clearance of bacteremia, to guide therapy duration and surgical timing. 8
When a valve is replaced during therapy, the regimen should be switched to the prosthetic‑valve‑specific protocol rather than the native‑valve protocol. 8
If resected valve tissue is culture‑positive, a full postoperative antimicrobial course is required; if culture‑negative, the recommended PVE duration is given minus the days already treated pre‑operatively. 8
Combination agents should be administered simultaneously or in close temporal proximity to maximize synergistic killing. 8

Oxacillin‑resistant Staphylococcus (typical of early PVE): vancomycin + rifampin for ≥ 6 weeks (AHA). 2, 3
Add gentamicin for the first 2 weeks to improve outcomes, although the recommendation is based on limited clinical data (AHA, Class IIb). 4, 3
If the isolate is gentamicin‑resistant but fluoroquinolone‑susceptible, replace gentamicin with a fluoroquinolone (AHA). 2, 3
Oxacillin‑susceptible Staphylococcus (rare): nafcillin or oxacillin + rifampin for ≥ 6 weeks (AHA). 5, 3
Add gentamicin for the first 2 weeks (AHA). 6, 3
For patients allergic to penicillins, substitute cefazolin or vancomycin (AHA). 5, 6
The 2‑week aminoglycoside adjunct is specifically recommended for staphylococcal PVE because of its high morbidity and mortality, despite limited supporting data (AHA, Class IIb). 4, 5

Enterococcal isolates must be tested for susceptibility to penicillin, vancomycin, and high‑level resistance to gentamicin and streptomycin (AHA). 5, 6
Effective therapy requires a synergistic combination of a cell‑wall‑active agent (penicillin, ampicillin, or vancomycin) plus an aminoglycoside (gentamicin or streptomycin) (AHA). 5, 6
Recommended treatment duration is 6 weeks for prosthetic‑valve infection (AHA). 5

CoNS are presumed oxacillin‑resistant unless susceptibility is definitively proven, especially when PVE occurs within 1 year of valve implantation (AHA). 2
The regimen mirrors that for oxacillin‑resistant S. aureus: vancomycin + rifampin for ≥ 6 weeks plus gentamicin for the first 2 weeks (AHA). 4, 2
Re‑testing of isolates from surgical specimens or relapsed blood cultures is mandatory because CoNS may develop rifampin resistance during therapy (AHA). 4, 5

The American College of Cardiology classifies early surgery (during the initial hospitalization before completing antibiotics) as a Class I indication for any of the following:
Surgery is frequently lifesaving, especially when PVE occurs within 12 months of valve implantation or involves an aortic prosthesis, because these scenarios are prone to perivalvular or myocardial abscesses and severe valvular dysfunction (AHA). 4, 5

Early PVE (≤ 12 months) is dominated by oxacillin‑resistant CoNS and other nosocomial pathogens, whereas late PVE (> 12 months) resembles native‑valve endocarditis with streptococci and enterococci (AHA). 2
The ACC warns that administering antibiotics before obtaining blood cultures in patients with unexplained fever and known valvular disease is harmful (Class III). 1, 7
Prosthetic‑valve infections involving aortic prostheses or occurring within 12 months have a high propensity for perivalvular extension and abscess formation (AHA). 4, 5

S. aureus* PVE carries extremely high mortality and almost always necessitates surgical intervention for optimal outcomes (AHA). 5, 6

Fungal PVE requires surgical valve replacement as a stand‑alone indication; amphotericin B is the traditional drug of choice, yet mortality remains unacceptably high (~80 % for mold‑related endocarditis) (AHA). 9
Complete removal of pacemaker/defibrillator systems (all leads and generator) is indicated when device infection is documented and is also reasonable for S. aureus or fungal IE even without proven device infection (ACC). 1, 7