Infective Endocarditis J B Handler M D Physician

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

Abbreviations n n n n n ABE- acute bacterial endocarditis SBE- subacute bacterial endocarditis IE- infectious endocarditis ASD- atrial septal defect VSD- ventricular septal defect PDA- patent ductus arteriosus Ao. V- aortic valve MVP- mitral valve prolapse TEE- transesophageal echocardiography n n n n 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 2

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

Pathogenesis n n 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. 4

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

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

Bacteremia n n 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. n n Frequent exposure to random bacteremia from frequent brushing/flossing. Presence of indwelling catheters, esp. central lines. 7

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

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

Endocarditis Images. google. com

Vegetations on MV Images. google. com

Vegetation: 2 - D Echo Images. google. com

Clinical Findings n n n Febrile illness often with nonspecific 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. 13

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

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

Immunologic Lesions Roth Spots Images. google. com

Varying Presentations n n Staph aureas and other more virulent organisms: acute course with 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. 17

Diagnostic Studies n n n 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. 18

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

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

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

Prevention n 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. n In past most forms of valve disease warranted Abx prophylaxis before procedure; now very limited. 22

Current Indications for Antibiotic Prophylaxis n n n 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 1 st 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 23

Antibiotic Prophylaxis n 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. 24

Antibiotic Prophylaxis n 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. 25

Treatment of Endocarditis n n Should be based on organism identified by blood cultures. Example- S viridans: Penicillin G 2 -3 million units every 4 hours x 4 wks. n n If add gentamycin 1 mg/kg IV q 8 hrs to PCN, course is shortened to 2 wks. Empiric Rx if needed while awaiting BC results: Vancomycin + Ceftriaxone, both IV. 26