Andersons pediatric cardiology 1496

Thetimingofaorticrootreplacementisevenmoreimportant.Itisclearthat
earlyaggressiveaorticrootreplacementforactiveinfectiveaorticroot
endocarditiswithperiannularabscessesismoresuccessfulthandelayedlast
resortsurgery.
OutcomesofInfectiveEndocarditisSurgery.
TheresultsofthepublishedstudiesonoutcomesofsurgeryinadultIE159,160
havepreviouslybeensummarized.147Thenumberofstudiesandresultsof
databaseshavesignificantlyincreasedinthelastseveralyears.Interpretationis
difficultbecausethemajorityofstudiesaremixingpatientswithheterogeneous
causesandoutcomemeasures.Methodsofadjustmentforvariousconfounding
factorshavebeenpublished.148,149
TheresultsofsurgeryforpediatricIEaremuchbetterthaninadults.Thisis
validforbothbefore2000150,151andafter2000.24,152,153Currently,postoperative
mortalityforpediatricIEstandsatapproximately10%,althoughsomereportit
at15%,154whichiscomparabletothatreportedinadults,157wherethemortality
ishigherinprostheticvalveIEandS.aureusIE.Outcomesofright-sidedIEare
generallybetter,butthisisnotthecaseifthereisadditionalleft-sidedIE.155
Resultsfortricuspidvalveendocarditissurgeryaremuchbetter156than
previouslyreported;thereisnorecurrenceaftertricuspidvalverepair;however,
thereis20%recurrenceriskforprostheticbiologictricuspidvalves.
RiskfactorsforperioperativedeathinpediatricIEareageyoungerthan1
year,prematurity,fungalorganisms,154andS.aureusIE.24Thesuggested
scoringsystemsforpredictingin-hospitalpostoperativemortalityforadult
IE157,158areunlikelytobeappropriateforuseinpediatricIE,althoughthis
remainstobetested.

AntithromboticTherapy
Thereisnoindicationfortheinitiationofantithromboticdrugs(thrombolytic,
anticoagulant,orantiplatelet)inpatientswithactiveIE.Recommendationsfor
patientsonoralanticoagulationwithvitaminKantagonistsforprostheticvalve
arebasedonalowlevelofevidence:ifthereisnostrokeorischemicstroke,

replacementoforalanticoagulationbyunfractionatedheparin(orlowmolecular-weightheparin)shouldbeconsideredfor2weeks(especiallyS.
aureus);ifthereisischemicstrokeorintracranialhemorrhage,all


anticoagulationshouldbestoppedfor2weeksandreinitiatedatalaterstage
onlyaftermultidisciplinarydiscussion.

Long-TermOutcomePostResolutionof
Infection
InpediatricIE,thereisafavorablelong-termevolutionafterresolutionof
infectionandhemodynamicproblems.Pulmonaryandcerebralembolism–
relatedchangeshavefavorableoutcomeinthepredominantproportionof
childrenwithIEifinfectionissuppressed.Therecurrencerateislow.154Large
pediatricstudiesonthelong-termoutcomesareindemand.
InadultswithIE,themeanrecurrenceriskis9%,withmostofthe
occurrencesduringthefirstyearaftertheacuteepisode,161beingatleast15%in
prostheticvalveIE.162,163S.aureusnativevalveIEinadultshasnotonlyworse
in-hospitalmortalityof25%butalsoreduced5-yearsurvivalof50%,and
delayedsurgeryisariskfactor,alongwithsepsisandheartfailure.164

SpecificSites,CausativeOrganisms,and
PredisposingFactors
UnusualLocation.
CoronaryfistulaIEisexceptionallyrareandisreportedtohaveoccurredin4%
ofalargegroupofadultpatients.165Itisusuallyatthevenousend,ithasnever
beenreportedatthearterialend,anditmayinvolvevalves.Itisrarelyreported
inchildren.166,167RightheartstructuresmayhaveIErelatedtoacoronarycameralfistula.168
Muralendocarditisrelatedtolinesispossibleinneonates.Itcanbeattachedto
amusclebundleintherightventricle,169,170totheeustachianvalve,171toan
additionalchordofmitralvalve,tothepatentforamenovale,andtointracardiac

surgicalpatchesforatrialseptaldefectclosure172andventricularseptaldefect
closure.173Therecanbemyocardialabscesses,includingofthepapillarymuscle.
Subendothelialabscessestothetransitionbetweensuperiorvenacavaandthe
rightatriumrelatedtolinehavealsobeendescribed.174
UnusualCausativeOrganisms.


Intracellularorganisms(especiallyBartonellaandCoxiellaburnetii)have
atypicalclinicalmanifestationswithprolongedcourse.Bartonellaspp.arean
importantcauseofculture-negativeendocarditis,withrecognizedriskfactorsof
alcoholism,homelessness,catexposure,andpreexistingvalvardiseaseinadults;
inchildrentheseriskfactorsarenotwelldelineated.
BartonellaIEdiagnosismightbedifficult175,176becausetheclinicalpictureis
characterizedbythefollowing:

■Longcourse
■NegativeBC(serologyhastoberequested)
■Bonemarrowsuppression
■Morepronouncedsplenomegaly
■Vasculitisimitatingwithantineutrophilcytoplasmic
antibodypositivity
■Involvement
BrucellaIEisalsoveryrareanddifficulttodiagnose,177–179withtheclinical
picturecharacterizedbydelayedmanifestationsfromthetimeofcontact,
arthritis,andatrioventricularblock.
MycobacteriumtuberculosisIEisextremelyrareandseenin
immunocompromisedpeople.Thefirstcaseinanimmunocompetentchildhas
alsobeenpublished.180
MycobacteriumchimaeraIEisarecentlyemergingpathogenthatis
thankfullydescribedtohavecausedfewcasesofIE.181–184Itisgeneticallya

memberoftheMycobacteriumaviumcomplex.Thelikelysourceiswaterfrom
heatercoolerunitsusedincardiacbypassunits.Itisdescribedinpatientsafter
openheartsurgery,causinginfectiononprostheticheartvalvesandvascular
grafts.Itismainlydescribedinadults;thenumberofcasesinchildrenislimited
tosingledigits.Itisdifficulttodiagnoseandtreatandislikelytohavepoor
outcome.ThesignificanceinpediatricIEisminimal,ifany.
UnusualPredisposingFactors
Confirmedinchildren.