Infective Endocarditis

1. Infective Endocarditis J.B. Handler, M.D. Physician Assistant Program University of New England

2. ABE- acute bacterial endocarditis SBE- subacute bacterial endocarditis IE- infectious endocarditis ASD- atrial septal defect VSD- ventricular septal defect PDA- patent ductus arteriosus AoV- aortic valve MVP- mitral valve prolapse TEE- transesophageal echocardiography TTE- transthoracic echocardiography PCN- penicillin HCM- hypertrophic cardiomyopathy AR- aortic regurgitation MR- mitral regurgitation TR- tricuspid regurgitation RV- right ventricle CABG- coronary artery bypass graft surgery Abbreviations

3. Key Terms • Infective Endocarditis: Infection on a cardiac valve or an endocardial surface within the heart. • Most cases are due to bacterial infection; fungal infections much less common.

4. Pathogenesis • In >50% of cases, underlying valve abnormality (acquired or congenital) provides source of turbulent blood flow/jet effectstransient bacteremia (from procedure or surgery) colonizationinfection. • Normal valve endocarditisbacteremia with virulent organism (like S aureas) infection. Example: IV drug abuser.

5. Common Underlying Lesions • Rheumatic valve disease; bicuspid AoV; aortic stenosis/sclerosis/regurgitation; mitral stenosis/regurgitation/prolapse; hypertrophic CM. • Most forms of congenital heart disease except ASD.

6. Common Underlying Lesions • Many surgically corrected congenital cardiac lesions except ASD, VSD and PDA. • CABG surgery and permanent pacemakers do not predispose to endocarditis. • Prosthetic heart valves.

7. Bacteremia • Portals of entry: skin, upper respiratory tract, oral cavity, GI (lower)/GU tracts. Commonly from procedures or surgery. • Some dental work/cleaning/flossing & related procedures; procedures and surgeries involving upper respiratory, lower GI & GU tracts. • Frequent exposure to random bacteremia from frequent brushing/flossing. • Presence of indwelling catheters, esp. central lines.

8. Organisms • S viridans, group D strep, Enterococcus faecalis, S aureas (most common organism). • HACEK organisms: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella • Prosthetic valve endocarditis: • Early (1st 2 mos): S aureas, S epidermitis, gram negative organisms and fungi • Late: Streptococci & Staph (coag+ and -)

9. Involvement of Cardiac Valves • Mitral and Aortic most commonly involved. • Classic valve lesion is a vegetation: mass of platelets, fibrin, colonies of bacteria + few inflammatory cells; visible on 2D echocardiography TEE>TTE. • RV endocarditis: Tricuspid ( 85% of cases) > pulmonic valve (15%) involved only in setting of IV drug abuse; organism usually S aureas.

10. Endocarditis Images.google.com

11. Vegetations on MV Images.google.com

12. Vegetation: 2- D Echo Images.google.com

13. Clinical Findings • Febrile illness often with with non- specific symptoms at onset. Fever usually elevated, often 38 degrees C, night sweats, arthralgias, myalgias, weight loss. Duration days to weeks. • Infectious emboli to brain, kidneys, joints, skin, lungs, mensenteric circulation & bowels: stroke, flank pain, arthritis, cough/dyspnea, abscesses, organ infarction, abd pain. • New or changing regurgitant heart murmurs may be present.

14. Clinical Findings • Peripheral lesions from micro emboli: • Petechiae (palate, conjunctiva) • Subungal (“splinter”) hemorrhages • Immunologic lesions: • Osler’s nodes: painful, raised lesions of fingers/toes • Janeway lesions: painless lesions of palms or soles • Roth spots: exudative lesions in the retina

15. Immunologic Lesions Osler’s Nodes Janeway Lesions Images.google.com

16. Immunologic Lesions Roth Spots Images.google.com

17. Varying Presentations • Staph aureas and other more virulent organisms: acute coursewith rapidly progressive, destructive infection (ABE); acute febrile illness, early embolization, valvular destruction and insufficiency. • Viridans streptococci, enterococcus: sub-acute course (weeks); systemic and peripheral manifestations predominate; valvular destruction gradual.

18. Diagnostic Studies • Blood cultures: essential to the diagnosis and treatment; must draw 3 sets, 1 hr apart; before considering empiric antibiotics. • Echocardiography: TEE 90%sensitive in localizing involved valve. TTE- 60% s. Pathognomonic finding is a vegetation. • Leukocytosis, anemia or hematuria depending on infecting organism, embolization and immune response.

19. Major: 2+ BC’s with typical organism Abnormal echo for vegetation or similar New regurgitant murmur Minor: Predisposing condition: valve abn; IV drug use Fever 38 degrees Vascular phenomenon: systemic emboli, infarction; cutaneous hemorrhage Immunologic lesion + BC not meeting above criterion Dx of Endocarditis: Modified Duke Criteria

20. Dx of Endocarditis: Modified Duke Criteria • Definite Dx: • 2 major criteria • 1 major +3 minor criteria • 5 minor criteria • Possible Dx: • 1 major +1 minor criteria • 3 minor criteria

21. Permanent Damage • Heart: AR, MR, TR, often severe due to destruction of valves. • Heart failure often a result of left sided valvular regurgitation (AR,MR). • Emboli to brainstrokes • Emboli elsewhere: kidneys, lungs, joints, bowels, other.

22. Prevention • Procedures likely to cause transient bacteremia can lead to endocarditis; prophylactic Rx with antibiotics beforehand can be protectivelimited applications (below). • Procedures: see slide #7 above • Significant change in recommendations made in 2007. • In past most forms of valve disease warranted Abx prophylaxis before procedure; now very limited.

23. Current Indications for Antibiotic Prophylaxis • Prosthetic heart valve • Prior episode of endocarditis • Unrepaired or incompletely repaired complex cyanotic congenital heart disease • Completely repaired cong ht disease with prosthetic material: for 1st 6 mos. post repair • Repaired cong heart defect with residual defect at the site of prosthetic patch/device. • Cardiac transplant patient with valvular disease Ref: http://www.ada.org/prof/resources/topics/infective_endocarditis_guidelines.pdf

24. Antibiotic Prophylaxis • Other valvular lesions, whether congenital or acquired, do not require endocarditis prophylaxis before bacteremia associated procedures. Risk of getting endocarditis out-weighed by risk of side effect or reaction to the antibiotic.

25. Antibiotic Prophylaxis • Antibiotic prophylaxis (dental work): oral amoxicillin 2 grams 30 to 60” before procedure. Alternatives: cephalexin, clindamycin, azithromycin or clarithromycin. See current: chap 33 table 33-5.

26. Treatment of Endocarditis • Should be based on organism identified by blood cultures. • Example- S viridans: Penicillin G 2-3 million units every 4 hours x 4 wks. • If add gentamycin 1mg/kg IV q8 hrs to PCN, course is shortened to 2 wks. • Empiric Rx if needed while awaiting BC results: Vancomycin + Ceftriaxone, both IV.