tACC Vol . IO Nn. 2 Up,, 1 .1-311-42
Infective Endocarditis : Risks and Prophylaxis JOHN S . CHILD, MD . FACC
Technical advances in medical and surgical trcalmcnl or patients wi1F congenital heart disease and adsanun-N in hacteriology and cardiac imaging has , e beer, ussugated with substantial changes in the clinical profile of infective endocarditis . Endocarditis after congenital heart surgery is a concern because postoperative residua and segtielac are potential foci ( 1-7). Hemodynamic monitoring wish indv :clling catheters causes areas of sterile cnducardiul damage of right-sided cardiac valves, increasing susceptibility 11) infection during bacteremia . Cardiac lesions at risk. These lesions are characterized by increased velocity of dam, at sites of significant pressure gradients, with the maximal deposition of organisms at the site of the low pressure sink immediately beyond the orifice or at the site of jet impact. Teleology of Fallot- physio€ogically analogous forms of cyanotic congenital heart disease and congenital aortic valve disease account fur uppiosiirately 379} of reported cases of infeciis'e endocarditis i-il ., Pulmonary valve stenosis. i s reported less frequently. and in coarclation of the aorta . the principal site of infection endoearditis is on a coexisting bicuspid aortic valve . Other frequently involved lesions include restrictive ventricular Septal defects and patent ductus arlcrfosus . The clefp anterior leaflet with mitral regurilntiun in patients with ostium primum atrial report defect represents a risk, but an uncumplicated ostirm secundum atrial Septal defect is at little m no risk. Poslopcrativc LEI errdocarditis in cungcmtal heart disease is most frcqucntly reported 1!-7) in patients with a palliative syslemic to pulmonary artery shunt and in patients with a prosthetic valve . Alpha streptococcus (riridans) and coaguiase-pusilicc Staphylococcus taureus) continue to constitute the ton most frequent etiologic agents of infective endocard,ti' . Inappro • priate administration or antihiulics to a febrile adult with congenital heart disease is often rcsponsihlc fur culturenegatiuc endocarditis or for rnrticallp treated puticnts . Culture-negative eau ocarditi, is a particular concern her use of loth the delay in diagnosis and the accurate choice of appropriate anliblotics . Sources of baceremin-Awareness of potential sources of bacteremia sets the stage for prophylasls IPt, Nevertheless . portals of entry arc not apparent in many putier(' . and when infective endocurditis is due to organisms of low virulence . s'_1y;4 of cases arc associated with identifiable medical
peeuedure, that cause bacteremia !It . Dental procedures that rcsull in interruption of a surface or gingival bleeding tcirIningg filimg or extraction) are common po'lcntinl portals entry and are thus most likely to respond to prophylaxis I1 .gl Translenl bacteremia may accompany nasotrachenl intuhalien or suctioning- surgery involving respiratory mucosu and introduction of a rigid bronchuscope . Fiber-optic bronchoscopy has minimal risk of hacteremia unless there is an untreated airway infection (SI . Low level bacteremia occurs during upper gastrointestinal endoscopy or transesophageal echocardiography . although the fregency is unclear (8-1 11 . For upper gastrointestinal endoscopy . the American Heart Association (12) does not recommend pro . phglaxi,. and the British Endocarditis Working Party (13) recommend, prophylaxis only for patients with a prosthetic valve . A single case of infective endocarditis (streptococcal) was temporally related to transesophageal echocardiography (Ilr. Bacteremia lenterocoeci and gram-negative rods) acc-smpanies urologic procedures provided urinary tract infeclion is present. but bacteremia is infrequent when the urine is sterile la1, Bacteremia seldom accompanies uneomplicated labor and delivery (81, but it is not always possible to predict an uncomplicated delivery . Similarly . a delivery does net qualild as uncomplicated if an episiotomy is required . Pnslpanulm mastitis (especially in nursing mothers) is a source of hacteremia. In the absence nfcoexisting infection . pruphylasts is not recommended for urethral catheterlza . u on .ddat , os,andcurettag, curentage- uncomplicated vaginal delivery, Cac,ariao suction . therapeutic abortion, sterilization prnce . lure, and insertion or removal of intrauterine devices (131 The incidence of infection after insertion of an intrauterine device is about 2 .51r annually ; these devices should be avoided in wmrtcn at risk of infective endccarditis (0). The American Heart Assawiation (12) takes the position that -'prophylactic amihiunes are not required in diagnostic cardiac catheterization and angingraphy because with adequate aseptic techniques . the occurrence of endocarditis is cstremclc low ." but a SSf incidence of infective endocarditis eras rcperlcd f6) in >200 pediatric patients undergoing carJicc catheterication . The risk of infective endocarditis accompanying cardiac surgery is related less to the underlyinc heart disease and surgical technique than to perioperalive predisposing factors for bacteremia. such as endotracheal inmbation and urethral catheterization.
JACC Vol . 18, Na 2 Annu al 1991911-42
c'H 1 .11 INI H10, 1, I NiIIJCARDITiS
Prevention of infective endocarditis . Good daily oral byglene is emphasized. Foods that induce caries should be minimized or avoided . The teeth should be cared for by twice daily brushing with a soft bridle toothbrush and regular gum stimulation and flossing . k dentist or hygienist should be seen twice yearly . It is believed that fluoridatica of drinking water plays a favorable rob; . and daily "gingival degerming" with certain mouthwashes or hydrogen peroxide may decrease plaque formation and gingivitis . Meticulous skin care is also to be emphasized . Patients should meticulously avoid squeezing pimples or pusruivs and should desist from nail biting or picking with the accompanying risk of paronychiu and periungual infection . Prophylactic advice best begins in childhood to instill good habits . Chemopnphvlaris requires direct medical intervention and advice . To be successful, recommendations must he not only bacteriologically effective. but also acceptable to the patient and physician in terms of cost . case of administration haute and duration) and few if any side effects . A complex, costly and painful regimen . no natter how ellective, results in lack of compliance and no protection . The selection of an antimicrobial agent for prophylaxis is based on anticipation of which organisms are likely to be confronted and on the desirability of bactericidal activity. In patients at highest risk of infective endocarditis (those with a prosthetic device, a surgically created systemic to pulmonary artery shunts or previously documented infective endocarditis )especially recurrent endocarditis)), parenteral regimens have been advised . However, risk categories have been rendered less important with the current recommendation of oral amoxicillin for dental and upper respiratory procedures (12 .13) . Oral amoxicillin is absorbed better than is penicillin V from the gastrointestinal tract, with higher and more sustained serum levels. For most patients in whom oral penicillin V was previously recommended, that choice remains acceptable 1131 . In patients with penicillin allergy . use of erythromycin, especially erythromycin cthylsuccinale and stcaratC,
is giving way to use of oral clirdamycin. Details retarding the preceding recommendations are available in the current American Heart Association statement 1121 on prevention of bacterial endocarditis and antiinfective endocarditis prophylaxis .
Karl.. EL, Riuh H. Gersony W, Manning J .
alluburutwe study of
u rpetlrnts .hu
have undergone cardiovascular surgery. Cheat, ,,o 1979.59:3 17-35, '- . DecIber D, Iksbs LL . Chakem S. Fullol's
ioiluw-up, Br Heart 1 1971 :}1 :t2 12 . 3 [maciho JS . Belcher P. Knight Wit. Infecuon of modified Bialnek shams . Br Heat J 1987 .58 :287-90, 4.
Johnson DH . Rosenthal A . Nadas AS . A funs year review of bacnrial
rnd,xard,i, in infancy and sh,Whad . Circulation 1975:57 :581-8. 5, John- CM . Rhodes KH . Pediatric endaardai •. Mayas Clin Pros 1982 : 57:86-94 . 6 . Kaplan EL Infertive enda.arduts in the pediatric age group . An over-- . In: Kaplan EL . Tannin AV . ads . Inteavve Fndocarditis. An American Hero Association Symposium . Dallas . TX : Amennan Hean Asacialiml. 1977 :$1-4 .
7 . Gersuny WM . Have, CJ . Bacterial endoearditis in patients with pulmonary sIeno,i, . anti[ sIcno,is or venMcular septa) defect . Circulation 1977.S61sappl 11 :1",'d_7. 0. Everest ED. Hirschmann IV . Transient bacteremia and endocarditis prupht,!anis: a nview. Medicine 1977 :56:61-77. 9. Corgi, G . Erbcl R . Hennahs KS. Wenchel H.M . Worst H-P. Meter J . Posaive blood cultures during Iansesophageal echocardiography . Am J Cardiol 1998:65:1404-5. 10. Chandraseken K . uansal RC . Mints 4S . Ross 1J . Shah PM . Impact of hansesophageal color flow Doppler echocardiography in current clinical practice . Echocardiography 1990 :7 :115-45 . If. Foster E. Kusumata FM . Sobol SM . Schiller NB. Streptococcal endocarditis temporally related to tmnaesopheural echavardio
San Echo 1990:5 :424-7 . C . Daaani AS. Barn AL, Chung KJ. el al. Prevention of bacterial andocarth . tis, recommendations by the American Heart Association . JAMA 1990: 264:2919-222 . 13 . Endoearditis Warkitg Party of the Banish Society for A ;.:isrimubial ehemomerapy. Anhhintie prophylaan of mieettve crdaardin . I_ao-c, 1990:31:88-9.
Assessment of Genetic Risk in Congenital Heart Disease EDMOND A . MURPHY, MU . REED E, PYER:-IZ, MU . PHU
Most studies an the genetics of congenital heart diseases have devoted much effort to traditional questions . questions that are often not central to the issue . There has been little attention to defining and exploring the fundamental problems to which coherent inquiry can be directed . After long inaction, interest in the genetics of congenital heart disease is slowly reviving. The approaches are on several quite dif-
ferent fronts: cytogenetic, hinchemical, analytic, statistical, mathematical and clinical. Though quite diverse and nut easily unified, they are by no means irreconcilable . The prospects are promising, exciting, even revolutionary ; but at this stage, the knowledge is germinal only and not ready for clinical application. We (1) recently reviewed some of this knowledge .