Download Infective Endocarditis

Endocarditis &
Infections of the Heart
Nausheen Akhter, MD
Core Curriculum
March 4, 2008
Contents
Epidemiology and Microorganisms
Pathophysiology
Clinical Features
Diagnosis and Treatment
Prevention and Guidelines
Other Infections: Bacterial Pericarditis, Infected Devices
Infective Endocarditis (IE)
IE is an infection of the endothelial lining of the
heart valves, mitral or tricuspid chorda tendinea,
valve annulus, and aortic root.
Pre-existing heart disease is found in 2/3 of the
cases of left-sided IE.
1/3 patients have normal or clinically
unrecognized valve disease.
3.6 to 7.0 cases/100,000 patient-years
Epidemiology
Predisposing
Conditions
RHD
CHD
MVP
DHD
IVDU
Other
None
Adults (%)
15 - 60 yr
> 60 yr
25-30
10-20
8
2
10-30
Rare
15-35
10-15
10
30
10
10
25-45
25-40
Braunwald 8th Edition
Epidemiology
Who is at high risk for developing endocarditis?
People with prosthetic heart valves, previous
incidents of endocarditis, complex congenital heart
disease, IVDU, and surgically devised systemic
pulmonary shunts.
What patients have a moderate risk for
developing endocarditis?
Acquired valvular dysfunction, HCOM, and
uncorrected congenital defects.
Zevitz, M. Pearls of Wisdom Board Review
Epidemiology
Patient Populations

MVP (7-30% of NVE not related to IVDU or
nosocomial infection)
Risk is mostly in pts with thickened valve leaflets (>5mm) and
MR murmur.


MVP + murmur 52/100,000 vs. no murmur 4.6/100,000 personyr
RHD
MV > AV

CHD (10-20% young adults, 9% older adults)
PDA, VSD, and biscupid aortic valve most common

HIV
Not significant risk for IE, unless IVDU
Braunwald 8th Edition
Epidemiology
Patient Populations

IVDU (2-5%/patient-year)
TV>MV>AV=multiple sites
TV IE is associated with pleuritic chest pain, SOB,
cough, and hemoptysis. CXR may have septic
pulmonary emboli.
IVDU is a risk factor for recurrent NVE
HIV, 27 to 73% of IVDU with IE, risk and mortality
is inversely related to CD4 counts.
Braunwald 8th Edition
Epidemiology
Patient Populations

Prosthetic Valve Endocarditis (PVE)
10 to 30% of all IE in developed countries
“Early” PVE, symptoms within 60 days, occurs at
greater frequency than “late”
0-12 months, PVE in mechanical > bioprosthetic
>12 months, PVE bioprosthetic > mechanical
By 5 years, PVE bioprosthetic = mechanical
Braunwald 8th Edition
Epidemiology
Patient Populations

Health care-associated
Nosocomial and community-acquired as a
consequence of indwelling devices
HD is independently associated with S. aureus.
Catheter-associated S. aureus bacteremia is the
predominant risk factor for IE in this group.
Treat as presumed IE, if persistent fever or
bacteremia for 4 days after catheter removed.
Braunwald 8th Edition
Distribution of Types of IE
Isolated AV IE is observed in 55-60% of cases.
Isolated MV IE occurs in 25-30% of cases.
IE of both valves occurs in 15% of cases.
Prosthetic valve IE constitutes 10-25% of all cases of IE.

Prosthetic valve IE is more common with prosthetic AV, multiple
valves, and after replacement of an infected native valve
Roldan CA. The Ultimate Echo Guide
Distribution of Types of IE
Right-sided IE constitutes 5-10% of all cases.



80% TV is involved
Most commonly associated with IVDU
Also occurs in patients with right heart wires or
catheters.
What is the incidence of culture-negative
endocarditis?

5-10%
Roldan CA. The Ultimate Echo Guide
Microorganisms
NEJM 345 (18), 2001
Microorganisms
What is the most common organism associated with
endocarditis?

Streptococcus viridans
What organisms are most frequently implicated in
endocarditis of IVDU?

Gram negative, fungal and S. Aureus
Fungi cause what percentage of PVE?

15%
What is the most frequent organism reported with
myocardial abscess?

S. Aureus
Zevitz, M. Pearls of Wisdom Board Review
Microorganisms
History of contact with mammals and/or birds
may suggest infection by what organisms?

Coxiella burnetii (Q fever), Brucella species or
Chlamydia psittaci
A nosocomial cluster of cases postoperatively
may be caused by what organisms?

Legionella or Mycobacterium species
What organism, once accounted for 25% of
cases, now only 1-2% of cases?

Neisseria gonorrhoeae
Zevitz, M. Pearls of Wisdom Board Review
Pathophysiology
It is hypothesized that platelet-fibrin deposition occurs
spontaneously on abnormal valves and at sites of cardiac
endothelium injury or inflammation and that these deposits are
called nonbacterial thrombotic endocarditis (NBTE).
NBTE are the sites at which microorganisms adhere during
bacteremia to initiate IE.
2 mechanisms in the formation of NBTE:


Endothelial injury
Hypercoagulable state.
3 hemodynamic circumstances that may initiating NBTE:

(1) a high-velocity jet striking endothelium; (2) flow from a high- to a lowpressure chamber; and (3) flow across a narrow orifice at high velocity.
Braunwald 8th Edition
Pathophysiology
Bacteremia converts NBTE to IE.
Bacteremia rates are highest for trauma of
the oral mucosa (especially gingiva), than
GU, and GI tract.
Braunwald 8th Edition
Braunwald 8th Edition
Clinical Features
Destructive effects of intracardiac infection
Embolization of septic fragments of vegetations
to distant sites causing infarction/infection
Hematogenous seeding of remote sites
An antibody response with subsequent tissue
injury caused by deposition of preformed
immune complexes or antibody-complement
interaction with antigens deposited in tissues.
Braunwald 8th Edition
Braunwald 8th Edition
Symptoms
% of Pts
Signs
% of Pts
Fever
80-85
Fever
80-90
Chills
42-75
Murmur
80-95
Sweats
25
Changing M
10-40
Anorexia
25-55
Neuro abn
30-40
Wt loss
25-35
Emboli
20-40
Malaise
25-40
Splenomeg
15-50
Dyspnea
20-40
Clubbing
10-20
Cough
25
Peripheral manifestations
Stroke
13-20
Osler nodes
7-10
H/A
15-40
Splinters
5-15
N/V
15-40
Petechiae
10-40
Myalgia/Arthral.
15-30
Janeway lesion
6-10
Chest pain
8-35
Roth spots
4-10
Braunwald 8th Edition
Clinical Features
What signs and symptoms are associated with a
myocardial abscess?

Low-grade fevers, chills, leukocytosis, conduction
system abnormalities, nonspecific ECG changes and
sign/sx of acute MI
Osler’s nodes are usually nodular and painful.

True
What other conditions are associated with
Osler’s nodes?

NBTE, gonococcal infection and hemolytic anemia
Zevitz, M. Pearls of Wisdom Board Review
Diagnosis: Duke’s Criteria
AHA/ACC Valve Guidelines 2006
Diagnosis
TTE sensitivity


Vegetation <5mm 25%
Between 6-10mm 70%
TEE sensitivity 90-100%
Prosthetic endocarditis

TEE >> TTE
Evangelista Heart 90: 614-617 (2004)
Diagnosis
Class I Indications for Echocardiography in IE of
Native and Prosthetic Valves:






Detection and characterization of valvular lesions,
hemodynamic severity, and ventricular compensation
Detection of vegetations and characterization of
lesions in patients with CHD
Detection of abscess, perforation or fistulas
Reevaluation studies in patients with complex
endocarditis
In patients with highly suspected culture-negative IE
Evaluation of bacteremia without a known source in a
patient with a prosthetic valve.
Roldan CA. The Ultimate Echo Guide
Diagnosis
Positive Echo findings:



Presence of vegetations defined as mobile
echodense masses implanted in a valve or mural
endocardium in the trajectory of the regurgitant jet or
implanted in prosthetic material with no alternative
anatomical explanation
Presence of abscess defined as definite region of
reduced echo density, or echolucent cavities within
annulus or adjacent myocardial structures
New dehiscence of valvular prosthesis
Roldan CA. The Ultimate Echo Guide
Braunwald 8th Edition
BMJ Vol. 333, Aug. 2006
Evangelista Heart 90: 614-617 (2004)
Detection of Complications
Valve perforation
Valvular, annular, or aortic root, or
myocardial abscess
Valve psuedoaneurysm
Fistulas
Ring dehiscence
Valvular regurgitation
PVE commonly extends beyond the valve ring into the
annulus which can cause dehiscence, paravalvular
regurgitation and conduction disturbances.
Braunwald 8th Edition
BMJ Vol. 333, Aug. 2006
Evangelista Heart 90: 614-617 (2004)
BMJ Vol. 333, Aug. 2006
Subaortic Complications of
AV Endocarditis
“TEE Recognition of Subaortic Complicatons in AV
endocarditis”
Karalis DG, et al. (Circulation 1992; 86: 353 – 362).
May 1988 – August 1991, 55 consecutive patients
44% (N = 24) had subaortic complications.
Secondary involvement of the mitral-aortic intervalvular fibrosa
(MAIVF) and the anterior mitral leaflet (AML)
Direct extension of infection and/or less commonly the infected AI
jet striking the subaortic structures
Abscess, aneurysm, perforation
Subaortic Complications of
AV Endocarditis
Subaortic Complications of
AV Endocarditis
Subaortic Complications of
AV Endocarditis
Subaortic Complications of
AV Endocarditis
Subaortic Complications of
AV Endocarditis
Subaortic Complications of
AV Endocarditis
Secondary infections of the subaortic structures
may be more common than appreciated.
The MAIVF and AML should be investigated in
all patients with AV endocarditis.
Thickening of the posterior aortic root or AML
with an eccentric MR color jet should alert to
possible subaortic complications.
Differential Diagnosis of IE
Valve excrescences
Ruptured chordae tendinea
Torn bioprosthetic leaflet
Libman-Sacks endocarditis
Rheumatic valvulitis
NBTE
Papillary fibroelastoma
Libman-Sacks Endocarditis
Rheumatic Valvulitis
Google Images
Papillary Fibroelastoma
Ruptured chordae tendinea
Google Images
Medical Therapy
NEJM 345 (18), 2001
Indications for Valve Surgery
Endocarditis-related valvular heart failure (mortality 56 –
86%)

Moderate to severe CHF (NYHA III or IV)
No control of infection, difficult-to-treat microbes
Embolic risk (vegetation length > 15mm strong predictor
of new EE and mortality)
Neurologic complications
Perivalvular infection/abscess
Valvular obstruction
Unstable prosthesis
Prosthetic infective endocarditis (esp. S. Aureus)
Fungal infective endocarditis
Circulation 2005; 112: 69-75
JACC 2001; 37: 1069
Prevention/Guidelines
Wilson, et al. Circulation. 2007; 115
Rationale
IE prophylaxis regimen has been evolving for
the past 50 years.
Basis for recommendations and quality of
evidence limited to expert opinion, small trails
[Class IIb, LOE C]
Several assumptions have led to development of
abx prophylaxis in humans, and these
assumptions have been recently questioned
Wilson, et al. Circulation. 2007; 115
Rationale
AHA/ACC guidelines have become overly
complicated and wrought with ambiguities,
making interpretation difficult for practitioners.
Potential consequences of changes include:
altering established practice, decreasing pts
eligible for prophylaxis, decreasing malpractice
suits and spurring more trials
Wilson, et al. Circulation. 2007; 115
Evidence
(1) Frequency, nature, magnitude, and duration of
bacteremia associated with dental procedures
(2) Impact of dental disease, oral hygiene, and type of
dental procedure on bacteremia
(3) Impact of antibiotic prophylaxis on bacteremia from a
dental procedure
(4) The exposure over time of frequently occurring
bacteremia from routine daily activities compared with
bacteremia from various dental procedures.
Wilson, et al. Circulation. 2007; 115
Evidence
Dental procedures


Transient bacteremia is common with manipulation of
the teeth and periodontal tissues.
Wide variation in reported frequencies of bacteremia
in patients resulting from dental procedures:
Tooth extraction (10% to 100%),
Periodontal surgery (36% to 88%),
Teeth cleaning (up to 40%)
Endodontic procedures (up to 20%)
Wilson, et al. Circulation. 2007; 115
Evidence
Routine daily activities

Unrelated to a dental procedure
Tooth brushing and flossing (20% to 68%)
Use of wooden toothpicks (20% to 40%)
Use of water irrigation devices (7% to 50%)
Chewing food (7% to 51%)
Wilson, et al. Circulation. 2007; 115
Evidence
Few published studies exist on the magnitude of
bacteremia after a dental procedure or from
routine daily activities, and most of the published
data used older, often unreliable microbiological
methodology.
There are no published data that demonstrate
that a greater magnitude of bacteremia,
compared with a lower magnitude, is more likely
to cause IE in humans.
Wilson, et al. Circulation. 2007; 115
Evidence
The magnitude of bacteremia resulting from a
dental procedure is relatively low, similar to that
resulting from routine daily activities, and is less
than that used to cause experimental IE in
animal.
Although the infective dose required to cause IE
in humans is unknown, the number of
microorganisms present in blood after a dental
procedure or associated with daily activities is
low.
Wilson, et al. Circulation. 2007; 115
Dental Recommendations
The vast majority of cases of IE caused by oral microflora most likely
result from random bacteremias caused by routine daily activities,
such as chewing food, tooth brushing, flossing, use of toothpicks,
use of water irrigation devices, and other activities. The presence of
dental disease may increase the risk of bacteremia associated with
these routine activities.
There should be a shift in emphasis away from a focus on a dental
procedure and antibiotic prophylaxis toward a greater emphasis on
improved access to dental care and oral health in patients with
underlying cardiac conditions associated with the highest risk of
adverse outcome from IE and those conditions that predispose to
the acquisition of IE
Wilson, et al. Circulation. 2007; 115
GI/GU Recomendations
The possible association between GI or GU tract
procedures and IE has not been studied as
extensively as the possible association with
dental procedures.
The administration of prophylactic antibiotics
solely to prevent endocarditis is not
recommended for patients who undergo GI or
GU procedures, including EGD or colonoscopy.
Wilson, et al. Circulation. 2007; 115
Summary of Major Changes
Wilson, et al. Circulation.
2007; 115
Highest Risk Patients
Wilson, et al. Circulation. 2007; 115
Regimans
Wilson, et al. Circulation. 2007; 115
Bacterial Pericarditis
Bacterial pericarditis is not synonymous with
purulent pericarditis.
50% have classic signs: chest pain, rub, pulsus
Staph and strep are the most common
organisms, 22-31%
Sources:

Lung 40%, hematogenous 22-29%, trauma 24-29%,
endocarditis/abscess 14-22%
Pankuweit S et al. Bacterial Pericarditis, Diagnosis and
Management. Am J Cardiovasc Drugs 2005; 5(2): 103-112.
Bacterial Pericarditis
Purulent pericarditis is fatal if untreated, 40% mortality.
TB Pericarditis:



Effusive-contrictive (30-50%)
85% mortality if left untreated.
Pericardial biopsy is more sensitive than pericardiocentesis
(100% vs 33%)
AIDS Pericarditis:


Leading cause of infectious pericarditis
35% MAI
Pankuweit S et al. Bacterial Pericarditis, Diagnosis and
Management. Am J Cardiovasc Drugs 2005; 5(2): 103-112.
Bacterial Pericarditis
Management:




First emperic antibiotic therapy (anti-staph
and aminoglycoside), then tailor therapy.
Open surgical drainage is preferred.
Rinsing pericardium with antibiotics,
urokinase/ streptokinase may help clear
infection.
Pericardiotomy is recommended for recurrent
effusions.
Pankuweit S et al. Bacterial Pericarditis, Diagnosis and
Management. Am J Cardiovasc Drugs 2005; 5(2): 103-112.
Echo Findings of Constriction
1) Increased pericardial thickness and
occasionally calcification

TEE measurement correlates with CT
2) Septal shudder/bounce
3) RV/LV inflow – increased E velocity

Due to early rapid diastolic filling
4) Tissue doppler – prominent E velocity

Major difference between constriction and restriction
5) Other: IV/hepatic v. dilation, biatrial
enlargement
Roldan CA. The Ultimate Echo Guide
Echo Findings of Constriction
UptoDate: Hemodynamics of Constrictive
Pericarditis vs Restrictive Cardiomyopathy
Device Infections
The Prospective Evaluation of Pacemaker Lead
Endocarditis study is a multicenter, prospective survey of
the incidence and risk factors of infectious complications
after implantation of pacemakers and cardioverterdefibrillators.
January 1 - December 31, 2000, 6319 consecutive
recipients of implantable systems were enrolled at 44
medical centers and followed up for 12 months.
Infections developed over 12 months in 42 patients,
incidence of 0.68/100 patients.
Circulation, Sept. 2007, 116: 1349-1355
Conclusions
The epidemiology of IE has changed in developed
countries.
TEE has a 95% sensitivity in detecting vegetations and
is also key in finding complications of vegetations.
Moderate to severe heart failure and vegetation length
are important indications for surgery.
Antibiotic prophylaxis regiman for IE was updated in
2007.
Questions/Comments??