Infective EndocarditisInfective EndocarditisSenior Oral Medicine

Chapter 2August 27, 2009

Susan Settle, D.D.S.

Infective Endocarditis

• A microbial infection of the endothelial surface of the heart or valves

• Usually is near congenital or acquired cardiac defects

• Designated by the causative organism• Also classified as NVE or PVE

Etiology

• Usually Bacterial– Staphylococcus aureus Endocarditis– Streptococcus viridans Endocarditis– Actinobacillus actinomycetemcomitans

Endocarditis• Sometimes Fungal

– Candida albicans Endocarditis

Etiology

• Streptococci most common cause (35-60%)– Mostly viridans group

• Staphylococci about 30-40 and gaining– S. aureus most common cause in IVDU’s– Incidence increasing in hospital-acquired

infections

Epidemiology

• Incidence <1% Of General Population

Epidemiology

• Population Groups At Greater Risk:– Rheumatic Fever History– Hemodialysis– Previous History Of Endocarditis– Patients With Prosthetic Valves– IV Drug Users (30% Risk Within 2 Years)

Predisposing Conditions

• Mitral valve prolapse• Aortic valve disease• Congenital heart disease• Prosthetic valve• Intravenous drug use• No identifiable cause in 25-47%

Epidemiology• More Common In Men• Median Age 50 Years• Acute Cases Increasing• Streptococcal Cases

Slightly; Fungal And Gram Negative Cases Increasing

Epidemiology

• Incidence Increases With Age, Probably Due To Increased Cardiac Disease And Decreased Immunity

• Prosthetic Heart Valve Infections Are Increasing

Dentistry And Endocarditis

• Streptococcus viridans: Usual Etiologic Agent

• Usually Is Not Acute (Subacute)– (That Is Why It Is Referred To As “SBE”)

• Incubation Period Approximately Two Weeks

Epidemiology• Mitral Valve Prolapse:

Only 1/4 Of MVP Patients Have Mitral Insufficiency (Regurgitation Or Murmur) - This Results In The Very Slight Increased Risk For Endocarditis

MVP

• Mitral valve prolapse accounts for 25-30% of adult cases of native valve endocarditis

• MVP is now the most common underlying condition among patients who develop infective endocarditis

Aortic Valve Disease

Accounts for 12-30% of IE cases

Epidemiology• Fenfluramine (Pondimin) And

Dexfenfluramine (Redux) Were Reported To Cause Cardiac Valvular Damage When Used For 4 Or More Months

• Premedication No Longer Indicated

Epidemiology

• Vena Cava Filters Or Umbrella Stents Placed To Catch Blood Clots Have Not Demonstrated Increased Risks

3 Types Of Endocarditis Lesions

• Cardiac Lesions• Embolic Lesions: Friable Cardiac

Lesions That Break Away• General Lesions

Cardiac Lesions

• Usually Valvular• Most Often Mitral Valve• May Cover The Entire Valve• Mass Of Platelets, Fibrin And

Bacteria• Sterile Vegetations May Occur In

50% Of Lupus Patients

Sites of Endocarditis Involvement

Embolic Lesions

• Osler’s Nodes: Are Small, Painful Petechiae In Extremities

Janeway Lesions

• Pathognomonic of IE• Non-tender dermal abscesses

Splinter HemorrhagesLate-appearing symptom in endocarditisThese represent damage to capillariesMay also appear due to nail trauma

General Lesions

• Enlarged Spleen• Arthritis• Clubbing Of Fingers• Cardiac Failure• Conduction Abnormalities• Stroke• Psychiatric Disease• Renal Failure

Mortality

• Overall Rate About 40%• Death Usually Due To Heart

Failure Resulting From Valve Dysfunction

• Highest Death Rate Is In Early Prosthetic Valve Endocarditis

Classic Triad - But May Not Always Be Present

1. Fever2. Positive Blood Culture3. Heart Murmur

• Sometimes Insidious Onset• “Flu-Like” Symptoms

Lab Findings

• +Culture In 95% Of BE• Strep viridans Most Commonly Causes SBE• Staph aureus Most Commonly Causes ABE• Electrocardiography: Will Determine If

Infection Progresses To Myocardium

Lab Findings

• Echocardiography - As Important As A Positive Blood Culture Are Results Which Show Vegetations, Abscesses, Etc.

Major Diagnostic Criteria

• Positive Blood Culture• Echocardiogram Findings

Of Endocardial Involvement• New Valvular Regurgitation

Minor Diagnostic Criteria

• Predisposing Heart Conditions• IV Drug Use• Vascular Emboli• Osler Nodes• Aneurysm• Roth Spots Of The Eye• Splinter Hemorrhages

Treatment

• Treat It Early!• Culture• Use Bactericidal Agents

–PCN G; Cefatriaxone; PCN G + Gentamicin; Nafcillin; Vancomycin

Treatment

• Use Adequate Dosage• Parenteral Route• Sufficient Duration: 4-6 Weeks Or

Longer

Dental Management

• Prevention In Susceptible Patients: An Academic Issue

• Very Few Cases Related In Time To Dental/Medical Procedures– Incidence Has Been Estimated To Be 100-200

Patients Susceptible To BE In A Dental Practice With 2,000 Patients

Antibiotic Prophylaxis

• Regimen Designed For Alpha-hemolytic Strep (S. viridans)

• No Clinical Trials Available To Show This Works! (Actually Prevents BE In Humans)

• 25-50% Hospital Antibiotic Usage Is For Prophylaxis

Antibiotic Prophylaxis

• Complications: Resistant Bacteria, Toxicity, Allergies, Suprainfections, Costs

• Will Not Prevent All Cases

Antibiotic Prophylaxis

• Allergy Morbidity Is Higher Than Endocarditis (Allergy To Premed)– 400-800 PCN Deaths Per Year

• Effective For Patients With Prosthetic Valves And Previous Endocarditis History

American Heart Association Guidelines

• Not Intended To Be A Standard Of Care• Not A Substitute For Clinical Judgment• Must Be Considered If You Receive A Medical

Opinion That Conflicts With The Guidelines (You Are Responsible For The Outcome Of Your Patient’s Dental Treatment)

American Heart Association Guidelines

• First Recommendations Were In 1955

• Can Still Develop Endocarditis Even When Using Guidelines

Prophylaxis Myths

• Most Cases Of BE Of Oral Origin Are Caused By Dental Procedures

• AHA Regimens Give Almost Total Protection Against Endocarditis After Dental Procedures

Prophylaxis Myths

• If A Patient Is Taking Antibiotics For An Infection Before The Dental Procedure, You Do Not Need To Change The Patient To Another Antibiotic Before The Dental Procedure

Prophylaxis Myths

• The Risk Of Endocarditis Is Greater Than The Risk Of Toxic Effects Of The Antibiotic

2007 AHA RecommendationsProphylaxis Indicated For The Following Groups

Of Patients:• Those with a previous history of endocarditis• Those with prosthetic cardiac valves• Post-heart transplant patients with

valvulopathy• Those with certain congenital types of heart

disease

Congenital Heart DiseaseIndications for Prophylaxis

• Unrepaired cyanotic CHD, including those patients with palliative shunts & conduits

• Completely repaired CHD with prosthetic material or device placed by surgery or catheter during the first 6 months after the procedure

• Repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device, which inhibits endothelialization

Dental Procedures For Which Prophylaxis Is Recommended

• All procedures involving manipulation of gingival tissue or the periapical region of teeth or perforation of oral mucosa

• Excluded procedures:– Routine anesthetic injections through noninfected tissue– Radiographs– Placement of removable prosthodontic or orthodontic

appliances– Adjustment of orthodontic appliances– Shedding of primary teeth and bleeding from trauma to

lips or oral mucosa

Nonvalvular Cardiovascular Devices

• Such as coronary artery stents, hemodialysis grafts• Routine antibiotic prophylaxis for dental procedures

is not recommended• However, prophylaxis is recommended if an abscess

is going to be incised & drained,• Or, if there is leakage present after the device is

placed

Not In This Presentation!

• Know Antibiotics in AHA Regimen• Know Dosages of These Antibiotics• Know The Regimen• Remember To Wait 9-14 Days Between

Premed Appointments To Avoid Antibiotic Resistance Development

• If Patient Is On A “Regimen” Antibiotic Switch To Another Drug In The Regimen