1. INFECTIVE ENDOCARDITIS
Nishith Patel
Waikato Cardiothoracic Unit Teaching

2. Guidelines
European society of cardiology 2015 guidelines for the management of ie
Aha guidelines 2015 for the management of ie in adults
Aats 2016 guidelines for the surgical treatment of ie
Nice guideline 2017 for the prophylaxis against ie

3. DIAGNOSIS OF IE

4. MODIFIED DUKE CRITERIA
Sensitivity – 80%.
Lower diagnostic accuracy in PVE and pacemaker or defib lead IE (ECHO is normal or inconclusive in 30%)

5. PRESENTATION - CLINICAL FEATURES
FEVER – 90% OF PATIENTS
+/- SYSTEMIC FEATURES – WT LOSS, ANOREXIA
HEART MURMUR – 85% OF PATIENTS
EMBOLIC COMPLICATIONS – 25% OF PATIENTS
EMBOLI TO BRAIN, LUNG OR SPLEEN – 30% OF PATIENTS
SUSPECT IE IN PATIENTS WITH FEVER AND EMBOLIC PHENOMENA

6. IMAGING Echo – TTE and TOE
PET-CT – possible ie diagnosis, detection of peripheral emboli
CT – coronaries, abscesses, pseudoaneurysms, brain lesions
MRI – cerebral lesions (greater sensitivity than ct)

7. ECHO

8. Sensitivity/Specificity
Echo – tte VS toe
Sensitivity/Specificity
TTE
TOE
VEGETATIONS
NVE
70% / 90%
96% / 90%
PVE
50%
92%
ABSCESS
50% / 90%
90% / 90%
Suspect PVE in patients with new paravalvular regurgitation

9. In summary, echocardiography (TTE and TOE), positive blood cultures and clinical features remain the cornerstone of IE diagnosis. When blood cultures are negative, further microbiological studies are needed. The sensitivity of the Duke criteria can be improved by new imaging modalities (MRI, CT, PET/CT) that allow the diagnosis of embolic events and cardiac involvement when TTE/TOE findings are negative or doubtful. These criteria are useful, but they do not replace the clinical judgement of the Endocarditis Team.

10. PROGNOSIS

11. PROGNOSTIC INDICATORS
IN-HOSPITAL MORTALITY RATE: 15-30%
4 MAIN FACTORS:
PATIENT CHARACTERISTICS
PRESENCE OR ABSENCE OF CARDIAC AND NON-CARDIAC COMPLICATIONS
INFECTING ORGANISM
ECHO FINDINGS

12. ANTIMICROBIAL THERAPY

13. PRINCIPLES Antimicrobials eradicate microbial burden
Surgery removes infected material and drains abscesses
NVE – 2-6 week therapy
PVE - >6 weeks therapy
Biofilms - house slow-growing and dormant microbes
Duration of therapy is based on the first day of effective abx therapy
Negative blood culture in the case of initial positive blood culture
Not on the day of surgery
New full course treatment starts if valve cultures are positivie

14. Blood culture negative ie

15. EMPIRICAL ANTIMICROBIAL THERPAY

16. SURGERY

17. SURGERY FOR IE 50% of patients with ie require surgery
Indications for surgery
Timing of surgery
Heart failure most common complication of IE (40-60% of NVE)
New valve regurgitation (chordal rupture, leaflet rupture, perforation, interference by the vegetation)
fistulae

19. PREOP ASSESSMENT Operative risk assessment Coronary Angiography
STS IE score – better predictive value vs euroscore II
Coronary Angiography
Indications: men >40y, post-menopausal women, 1 or more cv risk factor or hx of cad
Exceptions: aortic vegetations, emergency surgery
Ct coronary angio
Extracardiac infection
Eradicate any primary extracardiac focus of infection prior to surgery unless surgery is urgent
? BRAIN Imaging

22. SURGICAL APPROACH AND TECHNIQUES
Objectives:
Complete removal of infected tissues
Reconstruction of cardiac morphology
Bioprosthesis vs mechanical valves
Repair preferred in mv ie
Root abscessces
Homografts
Stentless xenografts

23. POSTOPERATIVE COMPLICATIONS
MORTALITY – 10-20% IN ACUTE CASES
COAGULOPATHY
RE-EXPLORATION FOR BLEEDING AND TAMPONADE
AKI – F
STROKE
LOW CARDIAC OUTPUT
PNEUMONIA
AV BLOCK – PREOP LBBB ON ECG

24. FOLLOW-UP RISK OF RECURRENCE – 2-6%
LONG-TERM SURVIVAL IN ALL TREATED PATIENTS:
80-90% AT 1 YEAR
60-70% AT 5 YEARS

25. Specific scenarios

26. PROSTHETIC VALVE ENDOCARDITIS
PVE occurs in 1-6% of patients with valve prostheses
PVE accounts for 10-30% of IE
Mechanical = bioprostheses
PVE – new valve regurgitation
Diagnostic challenge
Echo often negative
Persistent fever and new paravalvular leak
Additional imaging – ct, pet
Higher mortality rate – 20-40%
Surgery indicated in most cases

27. Right sided ie 5-10% of ie cases S.aureus accounts for 60-90% of cases
Commonly in IVDU
In-hospital mortality – 7%

28. PREVENTION

29. PREVENTION OF IE
A MOVE AWAY FROM ANTIBIOTIC PROPHYLAXIS FOR THE PREVENTION OF IE:
LOW GRADE BUT REPEATED BACTERAEMIA MORE RELEVANT FOR THE DEVELOPMENT OF IE THAN SPORADIC HIGH-GRADE BACTERAEMIA SEEN WITH DENTAL PROCEDURES
STUDIES DO NOT DEMONSTRATE AN ASSOCIATION BETWEEN INVASIVE DENTAL PROCEDURES AND OCCURRENCE OF IE
ESTIMATED RISK OF IE FOLLOWING DENTAL PROCEDURES WITHOUT ABX: 1 PER
2008 ONWARDS – RESTRICTION OF ABX PROPHYLAXIS FOR DENTAL PROCEDURE TO THE HIGEST RISK PATIENTS.

30. STUDIES
Dayer MJ, Jones S, Prendergast B, Baddour LM, Lockhart PB, Thornhill MH. Incidence of infective endocarditis in England, 2000–13: a secular trend, interrupted time-series analysis. Lancet 2015;385:1219–1228.
Duval X, Delahaye F, Alla F, Tattevin P, Obadia JF, Le MV, Doco-Lecompte T, Celard M, Poyart C, Strady C, Chirouze C, Bes M, Cambau E, Iung B, Selton-Suty C, Hoen B. Temporal trends in infective endocarditis in the contextof prophylaxis guideline modifications: three successive population-based surveys. J Am Coll Cardiol 2012;59:1968–1976.
Desimone DC, Tleyjeh IM, Correa de Sa DD, Anavekar NS, Lahr BD, Sohail MR, Steckelberg JM, Wilson WR, Baddour LM. Incidence of infective endocarditis caused by viridans group streptococci before and after publication of the American Heart Association’s endocarditis prevention guidelines. Circulation 2012;126:60–64.

31. Esc 2015 recommendations