Infective Endocarditis; Unusual site, unusual pathogen

IE, Unusual sites & unusual pathogensCardiac device and vascular prostheses

Mohamad Ashraf Ahmad, MD, PhD.

Lecturer of cardiology –Assiut University

Introduction • More than a century ago, Osler

took numerous syndrome descriptions of cardiac valvular infection that were incomplete and confusing and categorized them into the CV infections known as Infective endocarditis. Sir william Osler

1849-1919

• More recently, the syndromes of IE and endarteritis have been expanded to include infections involving a variety of cardiovascular prostheses and devices (PM, ICD, CRT,… ) that are used to replace or assist damaged or dysfunctional tissues.

Usual site of IE

• Endocarditis generally refers to inflammation on the valve leaflets. • The valves most commonly infected are

left-sided valves.• Infections of the tricuspid and pulmonary

valves are highly suspicious of intravenous drug abuse.

Unusual sites of IE• Cardiovascular Device–Related Infections:• Intracardiac (PM, ICD, CRT, LVAD, ASD/VSD

closure device, PDA closure, patches, … • Arterial (Coronary and peripheral stents,

vascular grafts, patches, ……..• Venous (IVC filter)

• Other unusual sites of IE (case reports):

Cardiac device related infective endocarditis:• CDREI is a severe disease associated with

high mortality. • The increased rates of cardiac devices

implantation coupled with increased implantation in elderly patients with more co-morbidities resulted in rising rate of CDREI.• The reported incidence CDRIE varies in

the literature from 0.06% to 7%.

Greenspon AJ et al., J Am Coll Cardiol 2011

Pathogenesis CDREI:

Pocket infection

• Subcutaneous pocket containing the device and the subcutaneous

segment of the leads.• Caused by infection at the time of

implantation, during subsequent surgical manipulation of the

pocket.• If the generator or subcutaneous

electrodes erode through the skin

Deeper infection

• Infection involves the transvenous portion of the lead, usually with

associated bacteremia and /or endovascular infection.

• Source of Infection:• Extension from pocket

infection• Less common, a result of

haematogenous seeding during a bacteraemia secondary to a

distant infected focus.

• The consequence may be formation of vegetations, which can be found anywhere from the insertion vein to the SVC, on the lead or on the tricuspid valve, as well as on the right atrial and ventricular endocardium.

Risk factors :

• Renal failure, corticosteroid use, CHF, DM, malignancy, post

operative pocket haematoma & anticoagulation use.

Patient factors:

• Type of intervention, device revisions, the site of intervention,

the amount of indwelling hardware, the use of pre-

procedural temporary pacing, failure of antimicrobial

prophylaxis, fever within the 24 h before implantation & operator

experience.

Procedural factors:

Causative pathogen:

• Staphylococci, and especially CoNS, account for 60–80% of cases .• Rare pathogen: Corynebacterium spp.,

Propionibacterium acnes, Gram-negative bacilli and Candida spp.

Sohail R M et al., J Am Coll Cardiol 2007

Diagnosis: • Systemic symptoms: Fever

(>38°C) frequently blunted particularly in elderly, Chills, Malaise, Anorexia, murmur on examination, • Local findings at generator

site: Erythema, Pain, Swelling, Warmth, Tenderness, Purulent drainage, Skin ulceration, Generator/lead erosion.

Sohail RM et al., Expert Rev Anti Infect Ther. 2010

• Echocardiography and blood cultures are the cornerstones of diagnosis.• Three or more sets of blood cultures are

recommended before initiation of antimicrobial therapy.• Lead-tip swap and extracted infected

tissues culture is indicated when the CIED is extracted.• Modifications of the Duke criteria have

been proposed including local signs of infection and pulmonary embolism as major criteria.

Echocardiography• TTE: Lead vegetations and tricuspid

involvement.• TEE allows visualization of the lead in

atypical locations, such as the proximal SVC, and of regions that are difficult to visualize by TTE.• ICE was recently found to be feasible and

effective in cardiac device patients.

TEE TTE

Early versus late CDRIE:

Arnold J et al., J Am Coll Cardiol 2012

Source of blood stream infection

Arnold J et al., J Am Coll Cardiol 2012

:Treatment CDRIE

Prolonged Antibiotic therapy

Complete device and lead extraction

1 -Antimicrobial therapy:

• I.V. antibiotics should be initiated before hardware removal, but after blood cultures. • Vancomycin should be administered

initially as empirical antibiotic coverage until microbiological results are known (CDRIE infections are secondary to MARSA in up to 50%).• The duration of therapy should be 4–6

weeks in most cases.

2 -Device and lead extraction:

• Complete removal of the system is the recommended treatment. Early and complete device removal showed improvement in survival at 1 year.• Percutaneous extraction is recommended in most

patients , however, this extractions have its own risk.• Transvenous lead extraction should be performed only

in centres with adequately trained teams and immediate cardiothoracic surgery backup.• Surgical extraction is indicated in:

• Percutaneous extraction is incomplete or impossible.• Infected valves that necessitate valve repair or replacement.

Lead extraction• Traction• Countertraction &

Telescoping Sheaths• Laser Sheath• Evolution

Mechanical Sheath

• Probably yes, but in a very limited group of selected patients. • Too frail or sick patients.• Patients with limited life expectancy due to

comorbidities or very old age. • These patients must have only local

infection or pocket erosion, with exclusion of systemic infection by blood cultures and a TEE.

Reimplantation• Reassessment of the need for

reimplantation.• Reimplantation on the contralateral side. • Blood cultures should be negative for at

least 72 h before placement of a new device.• Temporary pacing should be avoided if

possible.

Other unusual sites of IE

IE related to HOCM  The literature on IE in

HOCM is virtually confined to case reports.

Spirito et al., circulation 1999

Late IE of Amplatzer ASD occluder device:

• Bacterial endocarditis following ASD closure using Amplatzer device in pediatric is extremely rare• Case report of 10-year-old girl

who developed late bacterial endocarditis, 6 years after placement of an Amplatzer atrial septal occluder device.

Jha NK etal., world J cardiol 2015

:IE in Interatrial septal aneurysm• A 34-year-old man was admitted for recurrent fever

and non-productive cough for 2 months. He suffered from an advanced adenocarcinoma.

• Echocardiography was performed due to persistent bacteraemia with methicillin-resistant Staphyloccus aureus.

Shuenn J et al., Heart Asia 2011

Pulmonary valve endocarditis:• The pulmonic valve is the least commonly

involved valve in infective endocarditis. PV endocarditis is usually associated with tricuspid valve endocarditis, and isolated pulmonic valve endocarditis is exceedingly rare. • The predisposing factors include a congenitally

anomalous pulmonic valve, intravenous drug abuse, malignancy, the presence of indwelling pulmonary artery catheters, Postpartum and postabortion states.

Case of isolated PV endocarditis

Alcoholic and was malnourished patient with isolated pulmonic valve endocarditis caused by group B streptococcus was diagnosed with TEE.

Akram et al., Angiology 2001

Coronary stent infection• Although rare, coronary artery stent infections are

associated with a high mortality rate.• Case report of 66-year-old woman who had undergone a

difficult PCI to RCA with 3 overlapping stents.• Presented with weakness, malaise, fever and rigor as well

as midsternal chest pain.• Blood cultures grew MRSA. Antibiotic was initiated.• Few days later, The patient experienced cardiac arrest

with pulseless electrical activity and died.• Autopsy revealed the cause of death to be pericardial

tamponade due to rupture of the right ventricular myocardium.

• The stented portion of the RCA was enveloped by an abscess. Elieson M et al., TEX Heart Inst J , 2012

IE after TAVR• IE after TAVR is a rare but serious

complication.• A 72 year old lady complained of a 3

week history of feeling hot, sweaty, fatigue and poor appetite.• She had TAVR 4 years ago.• Blood cultures grew Enterococcus

faecalis on three separate culture samples.

Conor McQuillan, http://bjcahorizons.com/

Aortic coarctation endarteritis

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