299.1 🎓 醫學生版

299.1.0.1 📌 一頁重點

299.1.0.1.1 Prosthetic Valve Endocarditis (PVE)

299.1.0.1.1.1 Definitions

• Early PVE: ≤ 12 months post-implant
• Late PVE: > 12 months post-implant
• Indeterminate: difficult to distinguish

299.1.0.1.1.2 Incidence

• 1-6% of prosthetic valve recipients over lifetime
• Aortic > mitral position
• Mechanical > bioprosthetic in some series
• TAVR-related IE: ~ 0.5% per year

299.1.0.1.1.3 Etiology by Time

Early PVE (< 12 months) - Nosocomial / perioperative source - CoNS (S. epidermidis) most common - S. aureus (often MRSA) - Enterococcus - Fungi (Candida) - Gram-negative rods

Late PVE (> 12 months) - Similar organisms to NVE - Viridans Strep - Strep gallolyticus - Enterococcus - HACEK - S. aureus

299.1.0.1.1.4 Clinical Features

• May be more indolent or with paravalvular abscess
• HF from valve dysfunction
• Conduction abnormalities (annular abscess invading)
• Systemic embolism
• Persistent bacteremia despite treatment

299.1.0.1.1.5 Diagnosis

Modified Duke Criteria (2023 ESC) - New imaging modalities incorporated - TEE essential - CT cardiac for paravalvular - FDG-PET-CT for chronic PVE (> 3 months post-implant) - Microbiology + clinical evidence

Echo Findings - Vegetation on prosthesis - Paravalvular abscess (ring abscess) - Pseudoaneurysm - Dehiscence (new partial or complete) - New regurgitation (paravalvular leak) - Fistula

CT Cardiac - Complementary to echo - Best for paravalvular abscess, pseudoaneurysm

FDG-PET-CT - Most useful > 3 months post-implant (early post-op uptake confounder) - Sensitive for chronic PVE - Helps identify embolic complications

299.1.0.1.2 Treatment of PVE

299.1.0.1.2.1 Antibiotic Therapy

Empiric PVE (Before Culture Results) - Vancomycin + gentamicin + rifampin (within 12 months) OR similar broad-spectrum

Targeted Therapy

Staph PVE (CRITICAL) - Nafcillin/Oxacillin (MSSA) OR Vancomycin (MRSA) OR Daptomycin × - Gentamicin × 2 weeks (synergy) + - Rifampin × ≥ 6 weeks (biofilm penetration) - Adding rifampin crucial for Staph PVE (penetrates biofilm)

Viridans Strep PVE - Penicillin G OR ceftriaxone × 6 weeks - + Gentamicin × 2 weeks

Enterococcus PVE - Ampicillin + gentamicin × 6 weeks OR - Ampicillin + ceftriaxone × 6 weeks (DAILY)

HACEK PVE - Ceftriaxone × 6 weeks

Fungal PVE - Echinocandin (caspofungin, micafungin) ± amphotericin - Long-term suppression with fluconazole (oral) - Almost always surgical

299.1.0.1.2.2 Duration

• Minimum 6 weeks
• Often longer for fungal or complicated

299.1.0.1.2.3 Indications for Surgery (Class I — More Aggressive for PVE)

• HF from severe regurgitation, obstruction, dehiscence
• Locally invasive (abscess, pseudoaneurysm, heart block)
• Persistent bacteremia
• Recurrent embolism + large vegetation
• Fungal IE
• Staphylococcus aureus PVE (often)
• MDR organism

299.1.0.1.2.4 Surgical Approach

• Re-do sternotomy
• Valve replacement (mechanical or bioprosthetic)
• Root replacement for extensive abscess
• Often complex; high morbidity
• IE team / multi-disciplinary

299.1.0.1.2.5 TAVR-Related IE

• Increasing as TAVR expands
• Risk factors: chronic obstructive pulmonary disease, diabetes, vascular disease, transapical (less now), pre-procedure infection
• Treatment: long IV antibiotics; surgical decision based on patient + lesion
• Often re-TAVR + open surgery considered

299.1.0.1.3 CIED-Related Infection

299.1.0.1.3.1 Devices

• Pacemakers (PPM)
• Implantable cardioverter-defibrillators (ICD)
• Cardiac resynchronization therapy (CRT)
• Leadless pacemakers (Micra)

299.1.0.1.3.2 Incidence

• 1-3% of CIED implantations
• ↑ With re-do surgeries, age, comorbidities, immunocompromise

299.1.0.1.3.3 Types

• Pocket infection: localized to generator pocket
• Pocket infection extending to lead
• CIED-related endocarditis (CIED-IE): lead vegetation + bacteremia

299.1.0.1.3.4 Organisms

• CoNS (S. epidermidis) most common
• S. aureus (often MRSA)
• Gram-negative occasional
• Fungi rare

299.1.0.1.3.5 Clinical Features

• Local: erythema, swelling, discharge, exposure of generator
• Systemic: fever, bacteremia, sepsis
• Lead vegetation on echo (TEE)
• Embolic (pulmonary if RV lead)

299.1.0.1.3.6 Diagnosis

• Blood cultures
• Pocket exploration
• TEE (lead vegetation, valve involvement)
• FDG-PET-CT for chronic or unclear cases
• White cell scintigraphy

299.1.0.1.3.7 Treatment

Antibiotic Therapy: - Empiric: vancomycin + gentamicin - Targeted per culture - Duration: 2-4 weeks for pocket alone, 4-6 weeks for CIED-IE

Device Extraction (Class I): - Complete device + lead removal - Required for almost all CIED infections (even pocket) - Transvenous extraction at experienced center - Surgical extraction if transvenous fails

Re-Implantation: - After completion of antibiotics + negative cultures - Contralateral side often used - Delay 2-4 weeks for most - Subcutaneous-ICD alternative - Leadless pacemaker option

299.1.0.1.3.8 Prevention

• Aseptic technique
• Antibiotic prophylaxis pre-implant
• TYRX antibacterial envelope (PADIT trial 2019: reduced major infection)

299.1.0.1.4 LVAD-Related Infection

299.1.0.1.4.1 Types

• Driveline infection (most common)
• Pump pocket infection
• Bloodstream infection (often persistent)
• LVAD-related endocarditis (vegetation on LVAD or native valves)

299.1.0.1.4.2 Incidence

• 30-50% of LVAD recipients develop some infection over time
• Significant morbidity + mortality

299.1.0.1.4.3 Organisms

• S. aureus (often MRSA)
• CoNS
• Pseudomonas aeruginosa
• Enterococcus
• Candida

299.1.0.1.4.4 Treatment

• Long-term IV antibiotics (often months)
• Surgical debridement of driveline
• Pump exchange in severe (rare)
• Transplant if eligible
• Multidisciplinary

299.1.0.1.5 Other Device-Related IE

299.1.0.1.5.1 Transcatheter Edge-to-Edge Repair (MitraClip, TriClip)

• Rare but increasing
• Treatment as PVE

299.1.0.1.5.2 ASD/PFO/VSD Closure Devices

• Rare infection
• Treatment as foreign body infection
• Surgical removal often needed

299.1.0.1.5.3 Cardiac Patches + Conduits

• Risk similar to prosthetic valve
• Long-term antibiotics ± surgical revision

299.1.0.1.6 Mortality + Prognosis

299.1.0.1.6.1 Mortality of PVE

• Early PVE: 25-30%
• Late PVE: 15-25%
• High-risk: aggressive surgery may improve

299.1.0.1.6.2 Predictors of Worse Outcome

• HF
• Paravalvular abscess
• Staphylococcus aureus
• Fungi
• Delayed surgery
• Comorbidities

299.1.0.1.7 Endocarditis Team (Class I in 2023 ESC)

• Multidisciplinary specialty team
• Infectious disease + cardiology + cardiac surgery + microbiology + radiology + nuclear medicine + nursing
• Daily rounds
• Coordinated decisions
• Improves outcomes significantly

299.1.0.2 🩺 床邊速查

• Early PVE (< 12 mo): CoNS, S. aureus, GNR, fungi — nosocomial
• Late PVE (> 12 mo): similar to NVE (viridans, S. gallolyticus, HACEK)
• Empiric PVE: vancomycin + gentamicin + rifampin
• Staph PVE: nafcillin/vanc + gent + rifampin (biofilm penetration)
• Aggressive surgery indications in PVE
• FDG-PET-CT > 3 months post-implant for chronic PVE
• CIED infection: device extraction + IV antibiotics + re-implant contralaterally
• LVAD infection: driveline > pocket > bloodstream; multidisciplinary

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