Infecctive Endocarditis (IE)

1. Infecctive Endocarditis (IE) Dr mirdamadi Cardiologist, fellowship of echocardiography

2. Reference :Braunwalds heart disease Harrisons principles of internal medicine

3.  Acute IE is cused typically by staphylococcus aureus, with marked toxicity and progresses over days to weeks to valvular destruction and metastic infection. •  Subacute IE usally caused by viridans streptococci,enterococci,cougulase negative staphlococci or gram-negative coccoba cilli, evolves over weeks to months with only modest toxicity and rarely causes metastatic.

4. #Prototypic lesion of IE ,the vegetation is mass of platlets,fibrin ,microorganisms and inflammatory cells. • # Site of infection :heart valves (native or prosthetic) , site of VSD, mural endocardium at site of aberrent jets of blood or freign bodies ,on intracardiac devices ,arteriovenousshunt, arterioarterial shunt (PDA)or coarctation of aorta.

5. Predisposig conditin

6. Neonate : often TV involved as a consequencec of infected intravascular catheters or cardiac surgery • Childern and adults : RHD,CHD,MVP,DHD

7. IV drug abuser: • Mostly involved TV ,then MV and AOV •  Multiple site involvement may occure •  Recurrent IE may occure •  Although S.aureus is characteristic but unusual organisms and polymicrobial IE may occure. •  Infection with HIV is not a significant risk factor for IE unless associated with IV drug abuse.

8. Prosthetic valve endocarditic (PVE):great frequency during first 6 months • Early:within 60 days , as a complication of surgery and s.epidermidis is prominent. • Late :after 60 days ,as a common microorganism.

9. Transvenous pacemaker lead and/or implanted defibrillator :is usually nosocomial and is moe within weeks of implantation or generator change ,mostly s.aureus or s.aureus or s.epidermidis •  Healthcare –associated :after hospitaliazation or as a cnsequence of indwelling devices , or hemodialysis catheter , s.aureus is the most common cause.

10. Normal endothelium is resistant to infection and thrombus formation. •  Endothelial injury allows direct infection by virulent organisms or development of an uninfected platelet-fibrin thrombus (nonbacterial thrombotic endocarditis ,NBTE). •  Thrombus is a site of bacterial attachment during transient bacteremin •  NBTE: DIC,burn,SLE uremin ,valvular heart disease and intracardiac catheters, marantic endocarditis (malignancy and ohronic disease).

11. Organisms enter the bloodstream from mucosal surfaces ,skin or site of focal infection. •  Except for virulent bacteria (e.g.aureus) that can adhere to intact endothelium , other microorganisms adhere to NBTE. •  Organism proliferate and induce a procoagulant state at the site. •  Fibrin deposition with platelet aggregation ,stimulated by tissue factor and proliferating microorganisms,generate vegetation.

12.  Microorganisms can cause endocarditis have microbial surface components recognizing adhesin matrix molecules (MSCRAMMs) that mediate adherence to NBTE or injured endothelium •  Glucans or dextran is surface polysaccharides of streptococci •  •  Fibronectin is in lesion ofheart valves and produced by endothelial cells platlets and fibroblasts in response to vascular injury •  Fibronectine-binding proteins present on many gram-positive bacterin.

13. 910 • Bacteria in vegetations reach to 10 - 10 organisms per pram and organisms deep in vegetation are metabolically inactive (non growing) and relatively resistant to killing by antimicrobial agents

14. Clinical manifestations

15. Fever: is low –grade in subacute (<39.4c) but temperatures of 39.4° - 40 °c are often in acute if fever may be absent in elderly severely debilitated patient or who have marked cardiac or renal failure

16. Cardiac manifestation

17. Valvula regurgitation due to valvular damage or ruptured chordae • CHF due to valvular regurgitation or myocarditis or intracardiac fistula • Perivalvular abscesses (mostly AOV) • Pericarditis due to extension through epicardium (mostly AOV) • Heart block due to extension to conduction system (mostly AOV)

18. Non cardiac manifestation

19. Musculoskeletal symptom (arthralgin,myalgia,arthritis,back pain) •  Emboli to brain,coronary artery, extremities,mesenteric arteries •  Splenomegaly and clubbing •  Petechiae in conjunctiva ,buccal &palatal mucosa and extremities •  Splinter or subungual hemorrhages •  Osler nodes •  Janeway lesion •  Roth spot (oval retinal hemorrhage with pale center) •  Neurological symptum: stroke,ICH,cerebritis and microabscesses headache(potentially due to mycotic aneurysm),seizure,encephalopathy •  Renal insufficiency due to glomerulonephritis ,emboli, impaired hemodynamic andvantimicrobial toxicities.

20. %50 of patients associated with IV drug use ,infection is limited to the tricupid valve. •  These patient present with fever ,faint or no mumur,cough ,pleuritic chest pain ,pulmonary infiltration ,pyopneumothorax.

21. Laboratory findings

22. Anemia (normochromic,normocytic),false positive serologic test for syphilis and rheumatoid factor. •  ESR elevation (average 55mm/hr),positive CRP. •  Urinalysis (proteinuria, hematuria).

23. Blood culture :3 blood culture sets(two bottles per set )with at least 1 h separation from different vien over 24 h should be obtained. •  If culture remain negative after 48-72 h ,two or three additional blood culture sets should be obtained. •  5-10% of patiants with IE may have negative blood cultures .due to previous antibiotic therapy or fastidious organisms or fongal IE.

24. Echcardiography can confirmed IE, sizing of vegetation,detection of intracardiac complications assesment of cardiac function. •  TTE detects vegetation in 65% of patients and TEE in 99%

25. Diagnosis

26. Definite diagnosis is when vegetation obtained at cardiac surgery, an autopsy or from an artery (embolus) and examined histologically & microbiologically. • Duke criteria : • Developed on the basis of clinical , laboratory &echocardiography.

27. جدول ص 792 هارسون

28. Definite diagnosis according to documentation of 2 major ocriteria ,1 major &3 minor criteria or 5 minor criteria •  Rejection if an alternative dianosis is established if symptom resolve with <days of surgery or autopsy after < 4 days of therapy yields no histologic evidence IE •  Possible IE when 1 major &1 minor 0r 3 minor criteria are identified.

29. Antimicrobial therapy

30. It is difficult to eradicate bacteria from the avascular vegetation with largely nongrowing ,methabolically inactive bacteria •  Therapy must be bactericidal and prolonged , prenterally with high serum concentrations that will through passive diffusion lead to effective concenterations in the depths of vegetation.

31.  Antibiotic toxicities ,including allergic reactions occur in 25-40% of patients. blood test to detect renal ,hepatic & hematologic toxicity should be performed periodically. •  In most patients ,effective therapy results in resolution of fever in 5-7 days •  When fever persists for 7 days patients should be evaluated for paravaluvlar abscess and for extracardiac abscesses (spleen , kidney) or complications (embolic events) drug reactions or complications of hospitalization. •  Vegetation become smaller with treatment ,but at 3 months after cure half are unchanged and 25%are slightly larger.

32. Surgical treatment

33. Moderate to severe CHF due to value dysfunction •  Unstable prothesis, prosthesis orifice obstructed •  Uncontrolled infection •  Unavailable effective antimicrobial therapy (fungi,brucellae,pseudomonas aeruginosa) •  Relapse after optimal therapy •  Perivalvular extension •  Culture negative IE with persistent fever( >10d) •  Large (>10 mm) hypermobile vegetation 

34. prevention

35. Oral hygiene and dental health should be addressed before prosthetic valves are placed electively •  Oral irrigating devices are not recommended •  Use irrigating devices are not recommended •  Transient bacteremia occure after dental manipnlation (daily or surgical)

36. Antibiotic prophylaxis recommended in dental procedures that involve gingival tissue or perforate oral mucosa tonsilectomy a denoidectomy or bronchoscopy, surgery of infected skin or musculoskeletal tissue

37. Cardiac condition that need prophlaxis : •  Prosthetic valus •  Previous IE •  Unrepaired cyanotic CHD •  Repaired CHD with residual defect •  Completely repaired during the first 6 months after procedure •  Cardiac transplantation with cardiac valvulopathy

38. Prophylaxy:30-60 min before procedure: • Amoxicillin 2g po • Cephalixin 2g po( azithromycin or clatrithromycin 500g or clindamycin 600g)