Infective Endocarditis Diagnosis, Antimicrobial Therapy, and ...

Baddour et al Infective Endocarditis: Diagnosis and Management e395Table of ContentsIntroduction ..........................................e395Evidence-Based Scoring System ........................e396Level of Evidence ....................................e396Diagnosis ............................................e396Echocardiography ....................................e399Repeat Echocardiography .............................e400Intraoperative Echocardiography ......................e400Echocardiography at Completion of Therapy ..........e400Antimicrobial Therapy................................e400Antimicrobial Treatment Perspectives .................e400Overview of Viridans Group Streptococci, Streptococcusbovis, Abiotrophia defectiva, GranulicatellaSpecies, and Gemella Species ...............e401Highly Penicillin-Susceptible Viridans GroupStreptococci and S bovis (MIC 0.12 g/mL) ......e402Viridans Group Streptococci and S bovis WithPenicillin MIC 0.12 g/mL to 0.5 g/mL.......e403Abiotrophia defectiva and Granulicatella Species (FormerlyKnown as Nutritionally Variant Streptococci), Gemella Species,and Viridans Group Streptococci With Penicillin MIC0.5 g/mL........................................e403Endocarditis of Prosthetic Valves or Other ProstheticMaterial Caused by Viridans Group Streptococci andS bovis .............................................e403Streptococcus pneumoniae, Streptococcus pyogenes, andGroups B, C, and G Streptococci ...................e403Staphylococci ........................................e404Staphylococcus aureus................................e404Coagulase-Negative Staphylococci ....................e404Endocarditis in the Absence of Prosthetic ValvesCaused by Staphylococci ...........................e404Right-Sided Endocarditis in IDUs .....................e404Endocarditis in Non-IDUs ............................e405Endocarditis in the Presence of Prosthetic Valves or OtherProsthetic Material Caused by Staphylococci ..........e407Coagulase-Negative Staphylococci ....................e407Staphylococcus aureus................................e407Enterococci ..........................................e407Enterococci Susceptible to Penicillin, Vancomycin,and Aminoglycosides...............................e408Enterococci Susceptible to Penicillin, Streptomycin,and Vancomycin and Resistant toGentamicin ........................................e410Enterococci Resistant to Penicillin and Susceptible toAminoglycosides and Vancomycin..................e410Enterococci Resistant to Penicillin,Aminoglycosides, and Vancomycin .................e411HACEK Microorganisms .............................e412Non-HACEK Gram-Negative Bacilli ..................e413Enterobacteriaceae....................................e414Pseudomonas Species.................................e414Unusual Gram-Negative Bacteria......................e415Culture-Negative Endocarditis.........................e415Fungi ................................................e416Endocarditis in IDUs .................................e418Etiology of Endocarditis in IDUs .....................e418Complications and Their Management.................e419Surgical Therapy .....................................e419Congestive Heart Failure..............................e419Risk of Embolization .................................e420Anticoagulation ......................................e421Periannular Extension of Infection ....................e421Splenic Abscess ......................................e422Mycotic Aneurysms ..................................e422Intracranial MAs .....................................e422Extracranial MAs.....................................e423Outpatient Therapy ...................................e423Care at Completion of Treatment .....................e424Short-Term Follow-Up ...............................e424Long-Term Follow-Up................................e425Infective endocarditis (IE), like most other syndromes ofbacterial infection, has not escaped the impact of burgeoningantibiotic resistance among common pathogens. Since themost recent version of the American Heart Association(AHA) statement addressing treatment of IE was published in1995, 1 unparalleled changes have occurred in antibioticsusceptibility among the 3 major bacterial causes of IE:streptococci, staphylococci, and enterococci. Reports fromdifferent patient populations indicate that multidrug resistanceamong viridans group streptococci is now characteristicof many colonizing and infecting strains. 2–4 Oxacillin resistanceamong Staphylococcus aureus (ORSA) isolates is at anall-time high at many tertiary care institutions. In addition,reports 5–7 from several areas of the United States indicate thatcommunity-acquired infection resulting from ORSA is frequentlyseen. Perhaps the most alarming event for S aureus isthe development of intermediate- and high-level resistance tovancomycin, which was first described in Japan in 1997 8 andsubsequently reported in several other areas, including theUnited States. 9–11 Vancomycin resistance among enterococciis characteristic of many of the nosocomial isolates. Increasingaminoglycoside resistance among enterococci has beenreported 12 and has potential serious ramifications for treatmentefficacy if it becomes more prevalent among enterococcalisolates causing IE.Coupled with the recent deterioration of antibiotic susceptibilityamong these groups of Gram-positive cocci is theobservation that S aureus has surpassed viridans groupstreptococci as the leading cause of IE in several recent caseseries. 13–15 This has resulted in an overall worsening of theaverage clinical course of patients with endocarditis and hasbeen associated with an increased number of serious complicationsand higher mortality rates.The AHA’s recommendations for the treatment of IE havetherefore been updated in this statement to better addressthese microbiological changes. The present Writing Committeeconducted a comprehensive review of the literaturepublished between 1990 and 2004 to assist the group inupdating the previous version of the guidelines. Literaturesearches of the PubMed/MEDLINE databases were undertakento identify pertinent articles. Searches were limited tothe English language. The major search terms includedDownloaded from circ.ahajournals.org by on June 26, 2007