Michael Stander, Pharm.D.
Endocarditis: Goals Epidemiology Presentation of acute and subacute. Diagnosis: What is Dukes Criteria and how do we approach the diagnosis of endocarditis? Treatment: Understand what bacteria may cause endocarditis and be able to look up the appropriate treatment (antibiotics and length) Staphylococcus aureus bacteremia
Epidemiology There are about 10,000 to 15,000 new cases of endocarditis in the United States yearly There has been an increase in the occurrence of endocarditis (IE) secondary to longevity. Patients are living longer and have an in increase in degenerative valve disease, prosthetic valve replacement and exposure to nosocomial bacteremias. Staphylococcus aureus has emerged as the most common cause of IE In 2000, the Duke Criteria was modified to include Staphylococcus aureus as one of the typical bacteria to cause endocarditis
Epidemiology Most common predisposing factors. Intravenous Drug Users (IVDU) Prosthetic heart valve Native valve Healthcare associated IE has emerged as a common cause of bacteremia Poor dental hygiene Predisposing native valve conditions Presence of congenital heart diseases Age
Endocarditis: Definition Characterized as an infection on the surface of the heart. Most commonly associated with heart valves, but may occur at the site of a septal defect, chordea tendineae, or the surface of the myocardium. Infection consists of a collection of fibrin, platelets, microorganisms, and inflammatory cells. This is collectively referred to as vegetation.
Classification of Endocarditis Native valve (acute and subacute mentioned, but not discussed in the IDSA current guidelines) Acute Subacute Prosthetic valve Intravenous Drug Use (IVDU)
Bacteriology of Native Valve Acute (more virulent pathogens) Staphylococcus aureus (most common) Group A,B,C and G Streptococcus Gram-negative bacteria Subacute (less virulent pathogens) Viridans streptococcus group (most common) Abiotrophia sp Streptococcus bovis (Often associated with disease of the colon) Enterococcus sp HACEK (Haemophilus aphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae)
Bacteriology of Prosthetic Valve Bacteriology Staphylococcus aureus Staphylococcus epidermidis Gram-negative bacteria Candida sp Streptococcus sp Viridans Streptococcus Enterococcus sp Gp C and G streptococcus Endocarditis
Bacteriology of Endocarditis Associated with IVDU Commonly associated with tricuspid valve Bacteriology: Staphylococcus aureus (most common) Viridans streptococcus Gram-negative bacteria including Pseudomonas aeruginosa. Candida sp. May be polymicrobial
Native valve Subacute Presentation Symptoms are commonly vague often similar to a flu-like syndrome: fever, fatigue, anorexia, back pain, myalgias Viridans streptococcus from dental disease is the most likely cause. Septic emboli to skin can be seen when diagnosis is delayed IVDU Usually of the tricuspid valve. Emboli to the lung is common and presentation includes dyspnea, cough and chest pain. Septic emboli to the lungs can be seen on CXR or CT
Acute Presentation Comes on faster with higher fevers >102 F Varies depending upon the organism Staphylococcus aureus is the most common pathogen and causes a higher incidence of destruction of the heart valve (however, a muted SA endocarditis can be seen)
Acute vs Subacute Presentation Acute Subacute Onset: Days Weeks Presentation Pt appears acutely ill Pt may have vague signs Fever High >102F Low grade >100.4F Murmur May be present Usually present Bacteria Virulent Less virulent Subacute>acute Subacute>acute Peripheral Conjuctival petechiae Osler s nodes* manifestations Janeway lesions Roth s spots (<5% of pts)* More common Splinter hemorrhages Arthralgias* with subacute * Immune complex reaction initiated by a vegetation which effects the blood vessels
Manifestations of Endocarditis including Conjuctival Petechiae
Diagnosis of Endocarditis: Modified Duke s Criteria Major Criteria (2 major) Typical microorganism from 2 blood cultures such as Viridans streptococcus, Staphylococcus aureus, Enterococcus sp TEE showing oscillating intra-cardiac mass, abscess or new partial dehiscence of a prosthetic valve. New murmur with regurgitation Minor Criteria (1 major + 3 minor or 5 minor) Predisposing heart condition Fever > 100.4F Vascular phenomenon: splinter hemorrhages, Janeway lesions, etc Immunologic phenomena: Osler s nodes, Roth s spots, etc Serologic evidence of infection or positive BC not meeting major criteria
Staphylococcus aureus (SA) SA is associated with the highest mortality in endocarditis SA bacteremia is associated high mortality Most bacteria need some type of heart damage to causes IE, SA does not. SA contains factors that increase binding and invasion of heart valves and other tissue CLFA (fibrinogen-binding protein A): Triggers early valve colonization, but not invasion FnBPA (fibronectin-binding protein A): Does not increase colonization, but triggers endothelial invasion and inflammation
Archives of Internal Medicine.2003;163(17) 724 with at least one positive BC for SA 722 available for 12 week follow-up 43% were determined to have complicated SA bacteremia Endocarditis, septic arthritis, deep tissue abscess, vertebral osteomyelitis Other complications: : Epidural abscess, septic thrombophlebitis, psoas abscess, meningitis, mycotic aneurysm, etc Mortality 28% 4 Independent variables predictive of complicated SA bacteremia Positive BC after 48-72 hours Community acquired disease Persistent fever after 72 hours Skin examination suggestive of acute systemic infection All 4 present: 90% predictive None present: 16% had complications
Infectious diseases consultation lowers mortality from SA bacteremia Medicine 2009 Sept;88(5) Impact of ID consult (IDC) on clinical management and mortality in 240 patients with SA bacteremia Retrospective cohort study Results Pts with IDC were higher prevalence of severe complications. Antibiotics more appropriate in pts with IDC Blood culture were follow more closely Pts with IDC were more likely to receive debridement and prosthetic material removal Mortality in the IDC group 13.9% vs 23.7% in non ID treated pts
Questions?