Editing Infective endocarditis (section)

==Treatment==
High-dose [[antibiotic]]s are the cornerstone of treatment for infective endocarditis. These antibiotics are administered by the intravenous (IV) route to maximize diffusion of antibiotic molecules into vegetation(s) from the blood filling the chambers of the heart. This is necessary because neither the heart valves nor the vegetations adhering to them are supplied by blood vessels. Antibiotics are typically continued for two to six weeks depending on the characteristics of the infection and the causative [[microorganism]]s. Antibiotic treatment lowers the risk of embolic complications in people with infective endocarditis.<ref name="Hubers2020"/>

In acute endocarditis, due to the fulminant inflammation, empirical antibiotic therapy is started immediately after the blood has been drawn for [[blood culture|culture]] to clarify the bacterial organisms responsible for the infection. This usually includes [[vancomycin]] and [[ceftriaxone]] IV infusions until the infecting organism is identified and the susceptibility report with the [[minimum inhibitory concentration]] becomes available. Once this information is available, this allows the supervising healthcare professional to modify the antimicrobial therapy to target the specific infecting microorganism. The routine use of gentamicin to treat endocarditis has fallen out of favor due to the lack of evidence to support its use (except in infections caused by ''[[Enterococcus]]'' and nutritionally variant ''[[streptococci]]'') and the high rate of complications.<ref>{{cite journal | vauthors = Cosgrove SE, Vigliani GA, Fowler VG, Abrutyn E, Corey GR, Levine DP, Rupp ME, Chambers HF, Karchmer AW, Boucher HW | title = Initial low-dose gentamicin for Staphylococcus aureus bacteremia and endocarditis is nephrotoxic | journal = Clinical Infectious Diseases | volume = 48 | issue = 6 | pages = 713–21 | date = March 2009 | pmid = 19207079 | doi = 10.1086/597031 | doi-access = free }}</ref> In cases of subacute endocarditis, where the person's hemodynamic status is usually stable, antibiotic treatment can be delayed until the causative microorganism can be identified.{{citation needed|date=November 2021}}

Viridans group ''[[streptococci]]'' and ''[[Streptococcus bovis]]'' are usually highly susceptible to penicillin and can be treated with penicillin or ceftriaxone.<ref name=Baddour>{{cite journal | vauthors = Baddour LM, Wilson WR, Bayer AS, Fowler VG, Bolger AF, Levison ME, Ferrieri P, Gerber MA, Tani LY, Gewitz MH, Tong DC, Steckelberg JM, Baltimore RS, Shulman ST, Burns JC, Falace DA, Newburger JW, Pallasch TJ, Takahashi M, Taubert KA | display-authors = 6 | title = Infective endocarditis: diagnosis, antimicrobial therapy, and management of complications: a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: endorsed by the Infectious Diseases Society of America | journal = Circulation | volume = 111 | issue = 23 | pages = e394–434 | date = June 2005 | pmid = 15956145 | doi = 10.1161/CIRCULATIONAHA.105.165564 | doi-access = free }}</ref> Relatively resistant strains of [[viridans streptococci|viridans group ''streptococci'']] and ''Streptococcus bovis'' are treated with penicillin or ceftriaxone along with a shorter two-week course of an [[aminoglycoside]] during the initial phase of treatment.<ref name=Baddour/> Highly penicillin-resistant strains of viridans group ''streptococci'', nutritionally variant ''streptococci'' like ''[[Granulicatella]] sp.'', ''[[Gemella]] sp.'', ''[[Abiotrophia]] defectiva'',<ref>{{cite journal | vauthors = Kalavakunta JK, Davenport DS, Tokala H, King A, Khagny M, Gupta V | title = Destructive Abiotrophia defectiva endocarditis | journal = The Journal of Heart Valve Disease | volume = 20 | issue = 1 | pages = 111–2 | date = January 2011 | pmid = 21404910 }}</ref> and ''[[Enterococci]]'' are usually treated with a combination therapy consisting of penicillin and an aminoglycoside for the entire duration of 4–6 weeks.<ref name=Baddour/>

Some people may be treated with a relatively shorter course of treatment<ref name=Baddour/> (two weeks) with benzyl penicillin IV if infection is caused by viridans group ''streptococci'' or ''Streptococcus bovis'' as long as the following conditions are met:
* Endocarditis of a native valve, not of a prosthetic valve
* A [[minimum inhibitory concentration|MIC]] ≤ 0.12&nbsp;mg/l
* No complication such as [[heart failure]], [[Heart arrhythmia|arrhythmia]], or pulmonary embolism occurs
* No evidence of extracardiac complication like septic [[thromboembolism]]
* No vegetations > 5&nbsp;mm in diameter conduction defects
* Rapid clinical response and clearance of bloodstream infection

Additionally, oxacillin-susceptible ''Staphylococcus aureus'' native valve endocarditis of the right side can also be treated with a short 2-week course of a [[beta-lactam antibiotic]] such as [[nafcillin]] with or without aminoglycosides.

[[File:Histopathology of vegetation of bacterial endocarditis.jpg|thumb|Histopathology of a vegetation of bacterial endocarditis, taken from a valve repair, H&E stain. In a consistent clinical setting, neutrophils and fibrin is enough to diagnose a bacterial vegetation, even without visible bacterial colonies.]]
The main indication for surgical treatment is [[Regurgitation (circulation)|regurgitation]] or [[stenosis]]. In active infective endocarditis, the surgery should remove enough leaflet tissue to ensure eradication of the infectious process.<ref name="pmid28521809">{{cite journal| vauthors = Rostagno C, Carone E, Stefàno PL| title=Role of mitral valve repair in active infective endocarditis: long term results. | journal=J Cardiothorac Surg | year= 2017 | volume= 12 | issue= 1 | pages= 29 | pmid=28521809 | doi=10.1186/s13019-017-0604-6 | pmc=5437579 | doi-access=free }}</ref> Subsequent valve repair can be performed in limited disease.<ref name="pmid28521809"/> Replacement of the valve with a mechanical or bioprosthetic [[artificial heart valve]] is necessary in certain situations:<ref>{{cite journal | vauthors = Bonow RO, Carabello BA, Chatterjee K, de Leon AC, Faxon DP, Freed MD, Gaasch WH, Lytle BW, Nishimura RA, O'Gara PT, O'Rourke RA, Otto CM, Shah PM, Shanewise JS, Nishimura RA, Carabello BA, Faxon DP, Freed MD, Lytle BW, O'Gara PT, O'Rourke RA, Shah PM | display-authors = 6 | title = 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1998 guidelines for the management of patients with valvular heart disease). Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons | journal = Journal of the American College of Cardiology | volume = 52 | issue = 13 | pages = e1–142 | date = September 2008 | pmid = 18848134 | doi = 10.1016/j.jacc.2008.05.007 | doi-access = free }}</ref>
* Patients with significant valve stenosis or regurgitation causing heart failure
* Evidence of hemodynamic compromise in the form of elevated end-diastolic left ventricular or left atrial pressure or moderate to severe pulmonary hypertension
* Presence of intracardiac complications like paravalvular abscess, conduction defects or destructive penetrating lesions
* Recurrent septic [[emboli]] despite appropriate antibiotic treatment
* Large vegetations (> 10&nbsp;mm)
* Persistently positive blood cultures despite appropriate antibiotic treatment
* Prosthetic valve dehiscence
* Relapsing infection in the presence of a prosthetic valve
* Abscess formation
* Early closure of mitral valve
* Infection caused by fungi or resistant Gram-negative bacteria.

The guidelines were recently updated by both the [[American College of Cardiology]] and the [[European Society of Cardiology]]. There was a recent meta-analysis published that showed surgical intervention at seven days or less is associated with lower mortality.<ref>{{cite journal | pmid = 26869640 | doi=10.1136/heartjnl-2015-308589 | volume=102 | title=Early versus late surgical intervention or medical management for infective endocarditis: a systematic review and meta-analysis | year=2016 | vauthors = Anantha Narayanan M, Mahfood Haddad T, Kalil AC, Kanmanthareddy A, Suri RM, Mansour G, Destache CJ, Baskaran J, Mooss AN, Wichman T, Morrow L, Vivekanandan R | s2cid=12007082 | journal=Heart | issue=12 | pages=950–7}}</ref>