Endocarditis Flashcards
What is endocarditis?
Infection of the heart valves and other endocardial tissue (membrane that lines the chambers of the heart and covers the valves)
What patient groups are more likely to develop endocarditis?
Hospitalized patients (0.1%)
Patients over 50
Patients who inject drugs
Review slides 5 to 7 for illustration of endocarditis
What is the pathophysiology of endocarditis?
- Altered endocardial surface produces a suitable site for bacterial attachment and colonization
- Formation of platelet-fibrin thrombus on the altered surface
- Endocarditis most commonly happens from hematogenous spread (results in bacterial adhesions and colonization)
- Formation of vegetation of fibrin, platelets, and bacteria (protective cover for the bacteria so it can grow)
What are some characteristics of acute endocarditis?
- Severe and rapid clinical course
- History of bacteremia
- Normal valves are involved (require early treatment as valve may be destroyed in only a few days)
- Often Staph. aureus
What are some subacute characteristis of acute endocarditis?
- Illness often lasts months before diagnosed
- Usually some form of prior valve disease
- History of dental work or procedures
- Usually Streptococcal or Enterococcal
What is early onset prosthetic valve endocarditis?
Usually occurs within 1 year of surgery (usually Staphylococcal. can be gram - bacilli or fungal)
What is late onset prosthetic valve endocarditis?
Usually occurs after 1 year of surgery (same organisms as native valve endocarditis, ex. Strep)
How is prosthetic valve endocarditis treated?
Very hard to sterilize prosthetic valves, so treatment usually involves surgery
What are some risk factors for endocarditis?
- Age over 60
- Male sex
- Structural heart disease (valvular heart disease, congenital heart disease)
- Prosthetic valve
- Prior infective endocarditis
- Intravenous drug use
- Oral hygiene or dental pathology
- See more on slide 13
What is the organismal etiology of endocarditis?
Staphylocci (30-70%)
- Coagulase positive: 20-68%
- Coagulase negative: 3-26%
Streptococci (9-38%)
- Viridans group Strep: 10-28%
Enterococci (5-18%)
How do the organisms responsible for Streptococci associated endocarditis enter the bloodstream?
- Mostly coming from oral and respiratory flora (dental or respiratory tract procedures may introduce bacteria into bloodstream)
- Group D Strep is also found in GI tract
How do the organisms responsible for Staph aureus associated endocarditis enter the blood stream?
Usually seen in patients with history of IV drug use and early prosthetic valve endocarditis
How do the organisms responsible for Enterococci associated endocarditis enter the blood stream?
Found in gut or genitourinary tract (any GI/GU procedure may introduce into blood)
What are some signs and symptoms associated with endocarditis?
- Fever (86-96% of cases), can be low-grade
- Heart murmur (new or worsening of old murmur)
- Fatigue, weakness, weight loss, arthragias, myalgias (non-specific symptoms)
- Osler nodes (3%) and Janeway lesions (5%) (specific signs of endocarditis, see slide 17)
- Splinter hemorrhages, petechiae, vascular embolic events (see slide 18)
What are Osler nodes?
- Purplish SC nodules on tips of fingers and toes
- Painful or tender
- Caused by immune complex deposition
What are Janeway lesions?
Erythematous, non-painful macules on palms and soles
What are splinter hemorrhages?
They are thin, linear hemorrhages under nailbeds
What are petechiae?
- Small, red, painless hemorrhagic lesions
- Frequently on trunk, buccal mucosa, palate and conjunctivae
How do vascular embolic events occur?
- Pieces of vegetation in the heart can break off and can block blood supply in capillary beds (kidneys, lungs, brain, etc.)
What are the characteristics of IV drug use associated endocarditis?
- More often leads to right sided endocarditis
- Often presents as a pulmonary syndrome (fever, cough, hemoptysis(coughing up blood), pleuritic chest pain)
What are some blood lab changes for patients with endocarditis?
- Usually normocytic, normochromic anemia
- Increased WBC
- Increased ESR or CRP (indicate inflammation)
- RF may be increased (in 50% of cases)
What are some other lab tests performed on patients supected of having endocarditis?
Blood cultures and sensitivity:
- Get shedding of bacteria from vegetation
- Obtain 3 samples at different times or sites
- May be negative due to previous antibiotic therapy or difficult
ECG
- Visualize vegetation and see cardiac function and abnormalities
What are some major diagnostic criteria for endocarditis?
- Positive blood cultures (need 3 blood cultures)
- Evidence of endocardial involvement
What are some minor diagnostic criteria for endocarditis?
- Predisposition for infective endocarditis. fever, vascular phenomenon(hemorrhage or emboli), immunologic phenomenon (ex. Osler’s nodes, RF), positive blood culture
What is the minimum requirement for definite endocarditis diagnosis based on diagnostic criteria?
2 major; 1 major and 3 minor; or 5 minor
What is the minimum requirement for possible endocarditis diagnosis based on diagnostic criteria?
1 major and 1 minor; or 3 minor
What is the mortality rate for endocarditis?
In hospital: 15-20%
1 year after infection: approaching 40%
Up to 90% for fungal endocarditis
What damage caused by endocarditis results in relatively high rates of mortality?
- Destruction of valve tissue, fibrosis, abscess
- HF
- Cardiomyopathy
- Septic emboli
- Glomerulonephritis
- Stroke
What is the impact of vegetation on the treatment of endocarditis?
Vegetation protects bacteria from antibodies, macrophages, and antibiotics
What are some characteristics of bacteria encased in vegetation?
Bacteria are in high density with a slow rate of growth within biofilms and low microorganism metabolic activity
- Dense bacteria will produce beta-lactamase at higher concentrations
- Slow growth means fewer active penicillin-binding proteins
- Efficacy of drug varied depending on the degree of penetration into the vegetation, pattern of distribution within, and the size of vegetation
What are some treatment principles for endocarditis?
Treatment is generally IV for 4 to 6 weeks (courses as short as 2 weeks in certain circumstances)
Agents used must be bactericidal and in sufficient doses (often synergistic combinations are used)
What factors influence empiric antibiotic choice for infective endocarditis?
Depends on history
- Dental extraction (Strep suspected)
- GI procedure (Enterococci suspected)
- IV drug use (Staph. aureus suspected(
What is the empiric antibiotic choice for unknown source and native valve endocarditis?
Pen G or ampicillin + AMG
If suspect S. aureus, add cloxacillin or use Vancomycin + AMG
How are cultures monitored to determine causative pathogen in endocarditis?
Monitored for hours to days until pathogen is identified and regimen revised
What are some risk factors for Staph. aureus associated endocarditis?
- Intravenous drug user
- Indwelling cardiovascular medical devices (ex. pacemaker)
- Chronic skin disorders (ex. chronic scratching)
- Burns
- Diabetes mellitus
- Prosthetic valve replacement
- AIDS
- Solid organ transplantation
How is Streptococci associated endocarditis treated?
- Pen G or ceftriaxone for 4 weeks (native valve) or 6 weeks (prosthetic valve)
- Alt: Pen G or ceftriaxone with gentamicin for 2 weeks in certain patients
For penicillin-susceptible VGS and S. gallolyticus in patients with native valve endocarditis, what are the treatment reccomendations?
- Pen G or ceftriaxone are reasonable option for a 4 week treatment duration
- 2 week regumen that includes gentamicin is reasonable in patients with uncomplicated IE, rapid response, and no underlying renal disease
- Vancomycin for a 4 week treatment duration is a reasonable alternative in patients who cannot tolerate penicillin or ceftriaxone therapy
- The desired trough vancomycin level should range between 10 and 15 microgram/mL
Review slides 30 and 31
For penicillin-resistant VGS and S. gallolyticus in patients with native valve endocarditis, what are the treatment reccomendations?
- Penicillin for 4 weeks with single daily dose gentamicin for first 2 weeks of therapy
- If isolate is ceftriaxone susceptible, then ceftriaxone therapy alone can be considered
- Vancomycin alone may be a reasonable alternative in patients who are intolerant of beta-lactam therapy
Review slides 32 and 33
For A. defectiva and Granulicatella species and VGS with penicillin MIC over 0.5microgram/mL in patients with native valve endocarditis, what are the treatment reccomendations?
- Use a combination of ampicillin or penicillin+gentamicin as done for enterococcal IE with ID consultation
- If patient is intolerant to ampillin or penicillin, then use vancomycin alone (no need to add gentamicin)
- For pathogens that are ceftriaxone susceptible, then ceftriaxone+gentamicin is a reasonable alternative
For patients with prosthetic valves or other prosthetic material, what are the treatment reccomendations?
- Pen G or ceftriaxone for 6 weeks with or without gentamicin for the first 2 weeks is reasonable
- Can extend gentamicin to 6 weeks if MIC is more than 0.12microgram/mL
- Vancomycin can be used in patients who are intolerant of penicillin, ceftriaxone, or gentamicin
see slides 35 and 36 for more detail
For Strep pneumoniae in endocarditis, what are the treatment reccomendations?
- Four weeks of pencillin, cefazolin, or ceftriaxone is reasonable for IE caused by S. pneumoniae (Vanco is useful in patients intolerant of beta-lactam therapy)
For patients with S. pneumoniae in prosthetic valve endocarditis, what is the treatment reccomendation?
Six weeks of therapy (pencillin, cefazolin, or ceftriaxone) is reasonable for prosthetic valve endocarditis caused by S. pneumoniae
For patients with penicillin-resistant S. pneumoniae without meningitis in infective endocarditis, what is the treatment reccomendation?
High dose penicillin or a third generation cephalosporin (cefotaxime or ceftriaxone) is reasonable in patients with IE caused by penicillin-resistant S. pneumoniae
For patients with cefotaxime-resistant S. pneumoniae in endocarditis, what is the treatment reccomendation?
Add vancomycin and rifampin to third gen cephalosporin (cefotaxime or ceftriaxone)
Which specialist should be consulted when treating infective endocarditis caused by S. pneumoniae?
Consult with ID specialist due to complexities of IE as caused by S. pneumoniae
For patients with S. pyogenes in endocarditis, what is the treatment reccomendation?
4-6 weeks of therapy with Pen G or ceftriaxone (use vanco if patient is intolerant to beta-lactam therapy)
For patients with group B, C, or G streptococci in endocarditis, what is the treatment reccomendation?
Add gentamicin to Pen G or ceftriaxone for at least the first 2 weeks of a 4-6 week treatment course
What is the treatment reccomendation for patients with beta-hemolytic streptococci?
Consult with ID specialist to guide treatment
For patients with MSSA in native valve endocarditis, what is the treatment reccomendation?
Cloxacillin for 6 weeks (no need to add aminoglycosides)
see slides 38 and 39 for more details
For patients with MSSA and non-anaphylactic penicllin allergy in endocarditis?
Cefazolin for 6 weeks
see slides 38 and 39 for more details
For patients with MRSA in endocarditis, what is the treatment reccomendation?
Vancomycin or daptomycin for 6 weeks
see slides 38 and 39 for more details
For patients with S. aureus in prosthetic valve endocarditis, what is the treatment reccomendation?
Add an aminoglycoside and rifampin for 6 week therapy (increased risk of renal toxicity, so monitor regularly)
see slides 38 to 40 for more details
Are aminoglycosides alone effective against enterococci associated endocarditis?
No, do not use alone. Should use another antibiotic to be effective (synergistic effect)
What are some treatment options for enterococci associated endocarditis?
- 4-6 weeks of penicillin or ampicillin plus aminoglycoside (high rates of nephrotoxicity)
- Ampicillin+ceftriaxone (ceftriaxone is not directly effective, but it saturates penicillin binding sites allowing ampicillin to be more effective, synergistic effect)
What is the treatment option for penicillin-resistant enterococci associated endocarditis?
Use vancomycin
Do note vancomycin resistant enterococci also exists, refer to ID specialist in this situation
Review slide 43 for minor pathogens that can also cause endocarditis
What is the role of oral therapy in treatment of acute endocarditis?
Although there is evidence for non-inferiority for oral regimens following 10 days of IV treatment, they are not commonly used in practice
Should anticoagulation be continued in a patient that experienced a embolic event during an active prosthetic valve endocarditis infection?
No, anticoagulation should be stopped for at least 2 weeks to allow for thrombus organization and prevent the acute hemorrhagic transformation of embolic lesions
Can long-term antiplatelet therapy be continued in a endocarditis patient without bleeding complications?
Yes
How is endocarditis treatment monitored?
Blood cultures:
- Should be performed every 24 hours until negative
- Check susceptibility results to ensure optimal antibiotic choice
Drug specific monitoring (adverse effects, and serum concentrations)
Signs and symptoms of infection (temp, WBC, appetite, fatigue)
s/sx of HF (SOB, edema, weight gain)
What are some monitoring steps before completing antibiotic therapy for endocarditis?
- ECG to establish new baseline
- Drug rehab for PWIDs
- Antibiotic prophylaxis before certain dental procedures in specific patient groups
What are some short-term follow-up monitoring tips after completion of antibiotic therapy in endocarditis?
- At least 3 sets of blood cultures from separate sites for any febrile illness and before initiation of antibiotic therapy
- Physical examination for evidence of heart failure
What are some long-term follow-up monitoring tips after completion of antibiotic therapy in endocarditis?
- Evaluation of valvular and ventricular function
- Scrupulous oral hygiene and frequent dental professional office visits
Is prophylaxis for endocarditis a common therapy plan for patients after resolution of acute endocarditis?
No, risks outweight benefits of prophylaxis in most cases due to antibiotic SE and antimicrobial resistance
For patients that have had endocarditis, what is the one change they can make to reduce risk of a recurrent endocarditis episode?
Maintain excellent oral health and daily oral hygiene
What are some patient groups that are at higher risk for IE following a dental procedure?
- Prosthetic cardiac valve or prosthetic material
- Previous IE
- Congential heart disease
- Cardiac transplant patients who develop valvulopathy
What dental procedures are associated with risk of infective endocarditis?
All dental procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa
What is the standard endocarditis prophylaxis treatment regimen?
Amoxicillin 2g, 30-60 minutes before procedure (gets antibiotic into blood before pathogens)
For patients that are unable to take oral medication, what are some options for endocarditis prophylaxis?
- Ampicillin 2g IM or IV
- Cefazolin or Ceftriaxone 1g IM or IV
Review slide 52 for the different regimens for endocarditis prophylaxis before dental procedures
What are the treatment regimens for endocarditis prophylaxis before respiratory tract procedures?
Identical to prophylactic agents used before dental prophylaxis (Amoxicillin 2g, 30-60 minutes before procedure)
What types of respiratory tract procedures should endocarditis prophylaxis be given?
Any invasive procedure that involves incision or biopsy of the respiratory mucosa (ex. tonsillectomy, adenoidectomy)
What are the endocarditis prophylaxis treatment regimens for procedures involving the skin and musculoskeletal tissue?
Same list of appropriate agents as prophylaxis prior to dental procedures, but also include coverage for staphylococci and streptococcii
What are some skin procedures that do not need prophylaxis for endocarditis?
- Vaginal delivery
- Hysterectomy
- Tattoos
- Body piercing
What are the endocarditis prophylaxis treatment regimens for GI/GU tract procedures?
Prophylaxis no longer recommended for any scopes (colonoscopies, endoscopies) over concerns of resistance
If in active infection, ensure antibiotic treatment includes coverage for E. coli
What if a patient is already on antibiotics for a different condition but needs endocarditis prophylaxis?
- Choose a different class than what they are currently receiving
- Consider delaying procedure until antibiotic course is finished if possible
- If currently being treated for endocarditis and procedure is unavoidable, dose 30-60 min before procedure
Review slides 57 and 58 for summary of endocarditis slides
