Infective endocarditis
From IDWiki
Background
- Infection of endocardium, generally involving the heart valves, either prosthetic or native
Microbiology
- Bacteria
- Staphylococcus aureus (most common)
- Viridans group streptococci
- Coagulase-negative staphylococci
- Other streptococci
- Enterococci
- Gram-negative bacteria (5%)
- HACEK group
- Non-HACEK: particularly Pseudomonas aeruginosa and Escherichia coli
- Fungi
- Culture-negative endocarditis
Risk Factors
- Cardiac
- Prior endocarditis
- Prosthetic heart valve or implanted device
- Congenital heart disease, especially unrepaired cyanotic congenital heart disease
- Valve abnormalities
- Non-cardiac
- Intravenous drug use
- Indwelling intravenous lines
- Immunosuppression
- Recent dental work or surgical procedure associated with bacteremia
Clinical Manifestations
- In general, symptoms are fever, chills, and malaise in a patient at risk for endocarditis
- Tends to progress rapidly
- May have a new murmur, stroke syndrome, pulmonary embolism, arthralgias
- Specific organisms may be associated with specific risk factors
- Injection drug use: Viridans group streptococci and Pseudomonas aeruginosa
- Colon cancer: Streptococcus gallolyticus subspecies gallolyticus and Clostridium septicum
Subacute Bacterial Endocarditis
- Insidious onset with more pronounced constitutional symptoms progressing over weeks to months
Differential Diagnosis
- Non-infectious causes of endocarditis
- Any cause of fever or consitutional symptoms
Diagnosis
- Based on a combination of clinical exam, laboratory investigations, and ultrasound
- Refer to Modified Duke criteria
- C-reactive protein is fairly sensitive, while rheumatoid factor is fairly specific and decreases with treatment
- FDG-PET cardiac imaging is a new imaging modality
- Can be useful when TEE and CTA are inconclusive, and may be able to diagnose IE earlier than those other modalities
- May be most helpful in cases of prosthetic valves or other cardiac hardware
- However, it is non-specific, and cannot differentiate between infection and inflammation
- In these cases, a tagged WBC scan with SPECT can be helpful
- False positives with inadequate preparation, or other inflammatory disorders
- Most commonly is patients getting glucose (including in IV therapies) during the fasting period
- False negatives can be from very small lesion, or several weeks of antibiotics (needs to be off fo r2 to 4 weeks)
- To request, should have TEE done beforehand, then fax special access request to Ottawa
- Response within 24-48 hours, with imaging to be done at local PET (St. Joseph's)
- Can be useful when TEE and CTA are inconclusive, and may be able to diagnose IE earlier than those other modalities
Management
- Varies by causative organism and prosthetic vs. native valve
- In patients who are in acute heart failure, may need to consider the sodium content of the antibiotics used
Antimicrobial Selection
Valve | Antibiotic | Dose | Duration | Notes |
---|---|---|---|---|
MSSA and other oxacillin-susceptible Staphylococcus | ||||
NVE | oxacillin | 2 g IV q4h | 6 weeks | can treat for 2 weeks in uncomplicated right-sided NVE |
NVE | cefazolin | 2 g IV q8h | 6 weeks | in patients with non-anaphylactoid penicillin allergy |
PVE | oxacillin | 2 g IV q4h | ≥6 weeks | use cefazolin or vancomycin if allergy |
+ rifampin | 300 mg IV/PO q8h | |||
+ gentamicin | 1 mg/kg IV/IM q8h | 2 weeks | ||
MRSA and other oxacillin-resistant Staphylococcus | ||||
NVE | vancomycin | 15 mg/kg IV q12h | 6 weeks | target trough 10-20 μg/mL |
NVE | daptomycin | ≥8 mg/kg/dose | 6 weeks | |
PVE | vancomycin | 15 mg/kg IV q12h | ≥6 weeks | target vancomycin trough of 10-20 μg/mL |
+ rifampin | 300 mg IV/PO q8h | |||
+ gentamicin | 1 mg/kg IV/IM q8h | 2 weeks | ||
Enterococcus susceptible to penicillin and gentamicin | ||||
NVE/PVE | ampicillin | 2 g IV q4h | 4-6 weeks | 4 weeks if symptoms <3 months; 6 weeks if symptoms >3 months or if PVE |
+ gentamicin | 1 mg/kg IV q8h | |||
NVE/PVE | ampicillin | 2 g IV q4h | 6 weeks | alternative regimen if CrCl <50 |
+ ceftriaxone | 2 g IV q12h | |||
Enterococcus susceptible to penicillin and resistant to aminoglycosides | ||||
NVE/PVE | ampicillin | 2 g IV q4h | 6 weeks | |
+ ceftriaxone | 2 g IV q12h | |||
Enterococcus resistant to penicillin and susceptible to vancomycin and aminoglycosides | ||||
NVE/PVE | vancomycin | 15 mg/kg IV q12h | 6 weeks | |
+ gentamicin | 1 mg/kg IV/IM q8h | |||
Enterococcus resistant to penicillin, aminoglycosides, and vancomycin | ||||
NVE/PVE | linezolid | 600 mg IV/PO q12h | >6 weeks | |
NVE/PVE | daptomycin | 10-12 mg/kg IV q24h | >6 weeks | |
Viridans Streptococcus or Streptococcus gallolyticus highly susceptible to penicillin (MIC ≤0.12 μg/mL) | ||||
NVE | penicillin G | 3-4 MU IV q4h | 4 weeks | |
NVE | ceftriaxone | 2 g IV/IM q24h | 4 weeks | |
NVE | penicillin or ceftriaxone | as above | 2 weeks | |
+ gentamicin | 3 mg/kg IV/IM q24h | |||
NVE | vancomycin | 15 mg/kg IV q12h | 4 weeks | use if allergy, target 10-15 μg/mL |
PVE | penicillin G | 6 MU IV q4h | 6 weeks | |
± gentamicin | 3 mg/kg IV/IM q24h | 2 weeks | ||
PVE | ceftriaxone | 2 g IV/IM q24h | 6 weeks | |
± gentamicin | 3 mg/kg IV/IM q24h | 2 weeks | ||
PVE | vancomycin | 15 mg/kg IV q12h | 6 weeks | use if allergy |
Viridans Streptococcus or Streptococcus gallolyticus relatively resistant to penicillin (MIC >0.12 μg/mL) | ||||
NVE | penicillin G | 6 MU IV q4h | 4 weeks | |
+ gentamicin | 3 mg/kg IV/IM q24h | 2 weeks | ||
NVE | vancomycin | 15 mg/kg IV q12h | 4 weeks | use if allergy, target 10-15 μ/mL |
PVE | penicillin G | 6 MU IV q4h | 6 weeks | |
+ gentamicin | 3 mg/kg IV/IM q24h | |||
PVE | ceftriaxone | 2 g IV/IM q24h | 6 weeks | |
+ gentamicin | 3 mg/kg IV/IM q24h | |||
PVE | vancomycin | 15 mg/kg IV q12h | 6 weeks | use if allergy |
Streptococcus pneumoniae | ||||
NVE | penicillin | 3-4 MU IV q4h | 4 weeks | can use high dose if penicillin-resistant but without meningitis |
NVE | cefazolin | 2 g IV q8h | 4 weeks | |
NVE | ceftriaxone | 2 g IV/IM q24h | 4 weeks | |
PVE | penicillin | 3-4 MU IV q4h | 6 weeks | can use high dose if penicillin-resistant but without meningitis |
PVE | cefazolin | 2 g IV q8h | 6 weeks | |
PVE | ceftriaxone | 2 g IV/IM q24h | 6 weeks | |
Streptococcus pyogenes | ||||
NVE | penicillin G | 3-4 MU IV q4h | 4 weeks | can use high dose if penicillin-resistant but without meningitis |
NVE | ceftriaxone | 2 g IV/IM q24h | 4 weeks | |
PVE | penicillin G | 3-4 MU IV q4h | 6 weeks | can use high dose if penicillin-resistant but without meningitis |
PVE | ceftriaxone | 2 g IV/IM q24h | 6 weeks | |
Group B, C, or G Streptococcus | ||||
NVE | penicillin G | 3-4 MU IV q4h | 4 weeks | can use high dose if penicillin-resistant but without meningitis |
± gentamicin | 3 mg/kg IV/IM q24h | 2 weeks | ||
NVE | ceftriaxone | 2 g IV/IM q24h | 4 weeks | |
± gentamicin | 3 mg/kg IV/IM q24h | 2 weeks | ||
PVE | penicillin G | 3-4 MU IV q4h | 6 weeks | can use high dose if penicillin-resistant but without meningitis |
± gentamicin | 3 mg/kg IV/IM q24h | 2 weeks | ||
PVE | ceftriaxone | 2 g IV/IM q24h | 6 weeks | |
± gentamicin | 3 mg/kg IV/IM q24h | 2 weeks | ||
HACEK bacterium | ||||
NVE | ceftriaxone | 2 g IV/IM q24h | 4 weeks | |
PVE | ceftriaxone | 2 g IV/IM q24h | 6 weeks | |
NVE/PVE | ciprofloxacin | 500 mg PO q12h | 6 weeks |
Indications for Surgery
- Early valve surgery (that is, before discharge and completion of antibiotics) is recommended in some scenarios
- Left-sided endocarditis
- Acute heart failure
- Fungal endocarditis
- Highly-resistant organisms
- Heart block, annular or aortic abscess, or perforating valve lesion
- Bacteremia or fever lasting more than 5-7 days despite appropriate antimicrobials
- Severe valvular regurgitation and mobile vegetations >1 cm
- Prosthetic valve endocarditis with recurrent emboli despite appropriate antimicrobials
- Relapsed prosthetic valve endocarditis
- Right-sided endocarditis
- Severe tricuspid valve regurgitation with right heart failure despite medical therapy
- Persistent infection with difficult-to-treat organisms
- Tricuspid valve vegetation >2 cm
- Recurrent pulmonary emboli despite appropriate antimicrobials
Prevention
- Prophylaxis is recommended for high-risk patients who are undergoing higher-risk procedures
- Patient characteristics
- Prosthetic heart valve
- Previous infective endocarditis
- Unrepaired cyanotic congenital heart disease, or repaired within the past six months with prosthetic material in situ, or repaired with residual defect and with material in situ
- Cardiac transplantation with valvulopathy
- Procedures
- Dental procedures with manipulation of the gingiva or periapical region of teeth, perforation of mucosa
- This includes professional cleaning procedures
- Procedures involving incision of respiratory mucosa, including tonsillectomy and bronchoscopic biopsy
- Procedures on infected tissue (skin, bone, joint, etc)
- Dental procedures with manipulation of the gingiva or periapical region of teeth, perforation of mucosa
- Options
- Amoxicillin 2 g PO once, 30-60 minutes prior to procedure
- If allergy: clindamycin 600 mg PO once, 30-60 minutes prior to procedure
Further Reading
- Infective endocarditis in adults: diagnosis, antimicrobial therapy, and management of complications. Circulation. 2015 Oct 13;132(15):1435-86. doi: 10.1161/CIR.0000000000000296