Endocarditis

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Endocarditis

• Jim Czarnecki, D.O.
• Internal Medicine Lecture Series

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Introduction
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Background

• Defined as an infection of the endocardial
  surface of the heart, which may include one or
  more heart valves, the mural endocardium, or a
  septal defect.
• Three types
• Native valve (acute and subacute)
• Prosthetic valve (early and late)
• Related to intravenous drug use

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Native Valve Endocarditis
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Native Valve Endocarditis

• Usually has an aggressive course
• Typical causative agents are Staphlococcus aureus
  and group B streptococci.
• Underlying structural valve disease may not be
  present.
• Subacute endocarditis usually has a more indolent
  course than the acute form.

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Native Valve Endocarditis

• Alpha-hemolytic streptococci or enterococci,
  usually in the setting of underlying structural
  valve disease, typically are the causative agents
  of this type of endocarditis.

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Prosthetic Valve Endocarditis
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Prosthetic Valve Endocarditis

• Early prosthetic valve endocarditis occurs within
  60 days of valve implantation.
• Staphylococci, gram-negative bacilli, and Candida
  species are the common infecting organisms.

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Prosthetic Valve Endocarditis

• Late prosthetic valve endocarditis occurs 60 days
  or more after valve implantation.
• Alpha-hemolytic streptococci, enterococci, and
  staphylococci are the common causative organisms.

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Endocarditis and IV Drug Use
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Endocarditis and IV Drug Use

• Commonly involves the tricuspid valve.
• S. aureus is the most common causative organism.

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Pathophysiology
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Pathophysiology

• Infective endocarditis generally occurs as a
  consequence of nonbacterial thrombotic
  endocarditis, which results from turbulence or
  trauma to the endothelial surface of the heart
• Transient bacteremia then leads to seeding of
  lesions with adherent bacteria, and infective
  endocarditis develops.

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Pathophysiology

• Pathologic effects due to infection can include
  local tissue destruction and embolic phenomena.
• Secondary autoimmune effects, such as immune
  complex glomerulonephritis and vasculitis, can
  occur.

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Frequency
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Frequency

• In the US Incidence is 1.4 to 4.2 cases per
  100,000 people per year.
• Internationally Incidence of disease appears to
  be similar throughout the developed world.

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Mortality / Morbidity
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Mortality / Morbidity

• Increased mortality rates are associated with
• Increased age
• Infection involving the aortic valve
• Development of congestive heart failure
• Central nervous system (CNS) complications
• Underlying disease
• Mortality rates also vary with the infecting
  organism.

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Mortality / Morbidity

• Mortality rates in native valve disease range
  from 16-27
• Mortality rates in patients with prosthetic valve
  infections are higher.
• More than 50 of these infections occur within 2
  months after surgery.

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Gender / Age
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Gender / Age

• Gender
• The male-to-female ratio is approximately 21
• Age
• Can occur at any age
• Mean age of patients has gradually risen over the
  past 50 years
• Currently, more than 50 of patients are older
  than 50 years of age.

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Clinical Aspects
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History
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History

• Present illness history is highly variable.
• Symptoms are commonly
• Vague
• Emphasize constitutional complaints
• May focus on primary cardiac effects
• Secondary embolic phenomena

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History

• May present with signs of congestive heart
  failure (due to valvular insufficiency)
• Secondary phenomena could include focal
  neurological complaints due to
• Embolic stroke
• Back pain associated with vertebral osteomyelitis
• Fever and chills are the most common symptoms.

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History (Other)

• Other common complaints include
• Anorexia
• Weight loss
• Malaise
• Headache
• Myalgias

• Additional common complaints include
• Night sweats
• Shortness of breath
• Cough
• Joint pains

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Physical
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Physical

• Fever, either low-grade or intermittent, is
  present in 90 of patients.
• Heart murmurs are heard in approximately 85 of
  patients.
• Signs of neurologic disease occur in as many as
  40 of patients.
• Embolic stroke with focal neurologic deficits is
  the most common etiology. Others can be
  intracerebral hemorrhage and multiple
  microabscesses.

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Physical

• Signs of systemic septic emboli are due to left
  heart disease and are more commonly associated
  with mitral valve vegetations.
• Multiple congestive heart failure signs, such as
  distended neck veins, are frequently due to acute
  left-sided valvular insufficiency.

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Physical

• Classic signs of infective endocarditis are found
  in as many as 50 of patients. They include
• Petechiae common by nonspecific finding
• Splinter hemorrhages dark red linear lesions in
  the nailbeds
• Osler nodes Tender subcuaneous nodules usually
  found on the distal pads of the digits
• Janeway lesions Nontender maculae on the palms
  and soles
• Roth spots Retinal hemorrhages with small,
  clear centers rare and observed in only 5 of
  patients.

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Petechiae
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Splinter Hemorrhages
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Osler Nodes
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Osler Nodes
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Janeway lesions
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Roth Spots
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Physical (Other)

• Other findings
• Splenomegaly
• Stiff neck
• Delirium
• Paralysis
• Hemiparesis
• Aphasia
• Conjunctival hemorrhage

• Additional findings
• Pallor
• Gallops
• Rales
• Cardiac arrhythmia
• Pericardial rub
• Pleural friction rub

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Causes
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Causes Native Valve
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Causes Native Valve

• Rheumatic valvular disease (30) primarily
  involves the mitral valve followed by the aortic
  valve.
• Congenital heart disease (15) include patent
  ductus arteriosus, ventricular septal defect,
  tetralogy of Fallot
• Mitral valve prolapse with associated murmur (20)

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Causes Native Valve

• Degenerative heart disease includes calcific
  aortic stenosis due to bicuspid valve, Marfan
  syndrome, or syphilitic disease
• Approximately 70 of cases are caused by
  Streptococcus species including Streptococcus
  viridans, Streptococcus bovis, and enterococci.
• Staphlococcus species cause 25 of cases and
  generally demonstrate a more aggressitve acute
  course.

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Causes Prosthetic Valve
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Causes Prosthetic Valve

• Early disease, presenting shortly after surgery,
  has a different bacteriology and prognosis than
  late disease, which presents in a subacute
  fashion similar to native valve endocarditis.
• Infection associated with aortic valve prostheses
  is particularly associated with local abscess and
  fistula formation.
• This may lead to heart block, shunting of blood
  to the right atrium, or pericardial tamponade.

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Causes Prosthetic Valve

• Endocarditis can occur in association with
  intravascular devices.
• Infection that occurs early after surgery may be
  caused by a variety of pathogens, including S.
  aureus and S. epidermidis.
• Late disease is most commonly caused by
  streptococci.

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Causes IV Drug Use
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Causes IV Drug Use

• Most commonly involves the tricuspid valve,
  followed by the aortic valve.
• Two thirds of patients have no previous history
  of heart disease and no murmur on admission.
• Diagnosis of endocarditis in intravenous drug
  users can be difficult and requires a high index
  of suspicion.

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Causes IV Drug Use

• S. aureus is the most common (lt50 of cases)
  etiologic organism. Other causative organisms
  include streptococci, fungi, and gram-negative
  rods (eg. Pseudomonads, Serratia species).

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Causes Fungal Endocarditis

• Found in intravenous drug users and intensive
  care unit patients who receive broad-spectrum
  antibiotics.
• Blood cultures are often negative, and diagnosis
  frequently is made after microscopic examination
  of large emboli.

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Causes Diagnosis

• Usually made using Duke Criteria (link is on IM
  website). Major criteria include
• Multiple positive blood cultures for the
  infecting organism
• Echocardiographic evidence of endocardial
  involvement or a new regurgitant murmur on
  physical examination

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Differentials
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Differentials

• Connective tissue disease
• Fever of unknown origin
• Intra-abdominal infections
• Septic pulmonary infection
• Tricuspid regurgitation

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Workup
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Lab Studies

• Send baseline studies
• CBC
• Electrolytes
• Creatinine
• BUN
• Glucose
• Coagulation Panel

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Lab Studies

• Two sets of blood cultures have greater than 90
  sensitivity when bacteremia is present.
• Anemia of chronic disease is common in subacute
  endocarditis
• ESR, while not specific, is elevated in more than
  90 of cases.
• Proteinuria and microscopic hematuria are present
  in approximately 50 of cases.

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Lab Studies

• Leukocytosis is observed in acute endocarditis
• Anemia is present in subacute endocarditis.
• Rheumatoid factor is noted in subacute
  endocarditis.
• Serology for Chlamydia, Q fever (Coxiella), and
  Bartonella may be useful in culture-negative
  endocarditis.

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Imaging Studies

• Echocardiography
• Transthoracic echocardiography has a sensitivity
  of approximately 60.
• Transesophageal echocardiography has a
  sensitivity of more than 90 for valvular
  lesions.
• Both techniques are highly specific for valvular
  vegetations.

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Vegetation on Mitral Valve
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Imaging Studies

• Imaging studies are particularly indicated with
  culture-negative cases, such as in fungal
  endocarditis.
• Echocardiography is highly useful to assess local
  complications, such as abscesses.
• Chest radiography Pulmonary embolic phenomena
  strongly suggest tricuspid disease.
• Ventilation/perfusion (V/Q) scanning This may be
  useful in right-sided endocarditis.
• CT scanning helpful in localizing abscesses.

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Imaging Studies

• EKG
• Nonspecific changes are common
• First-degree AV block and new interventricular
  conduction delays may signal septal involvement
  in aortic valve disease both are poor prognostic
  signs.
• Cardiac catheterization indicated to determine
  the degree of valvular damage.

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Treatment
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Treatment

• Focus is on making the correct diagnosis and
  stabilizing the patient with acute disease and
  cardiovascular instability
• Most cases the etiologic microbial agent is not
  known
• General recommendations three (3) sets of blood
  cultures over a few hours, and then empiric
  antibiotic therapy may be administered.

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Treatment

• General Measures
• Treatment of congestive heart failure
• Oxygen
• Hemodialysis (may be required in patients with
  renal failure)
• Consultations
• Cardiology
• Cardiothoracic Surgery Service
• Infectious Diseases Service

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Medication
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Medication

• Empiric antibiotic therapy is chosen based on the
  most likely infecting organism.
• Native valve disease usually is treated with
  penicillin G and gentamicin for synergistic
  treatment of streptococci.
• Patients with history of IV drug use treated
  with nafcillin and gentamicin to cover
  methicillin-sensitive straphylococci.

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Medication

• Infection of a prosthetic valve may include
  methicillin-resistant Staphylococcus aureus
  thus vancomycin and gentamicin may be used.
• Rifampin also may be helpful in patients with
  prosthetic valves or other foreign bodies
  however, it should be used in addition to
  vancomycin or gentamicin.

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Follow-up
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Deterrence / Prevention

• Consider prophylaxis against infective
  endocarditis in patients at high risk
• Presence of prosthetic heart valve
• History of endocarditis
• History of rheumatic heart disease
• Congenital heart disease with a high-pressure
  gradient lesion and mitral valve prolapse with a
  heart murmur

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Deterrence / Prevention

• The presence of coronary artery stenting is not
  considered to place the patient at high risk for
  endocarditis.

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Deterrence / Prevention

• Consider prophylaxis in patients before they
  undergo procedures that may cause transient
  bacteremia, such as
• Ear, nose, and throat (ENT) procedures associated
  with bleeding, including dental manipulations and
  nasal packing
• Incision and drainage of an abscess
• Anoscopy and Foley catheter placement when a
  urinary tract infection is present or suspected

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Complications
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Complications

• Myocardial infarction, pericarditis, cardiac
  arrhythmia
• Cardiac valvular insuffiency
• Congestive heart failure
• Sinus of Valsalva aneurysm
• Aortic root or myocardial abscesses
• Arterial emboli, infarcts, mycotic aneurysms
• Arthritis, myositis
• Glomerulonephritis acute renal failure
• Stroke syndromes
• Mesenteric or splenic abscess or infarct

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Prognosis
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Prognosis

• Acute endocarditis due to S. aureus is associated
  with a high mortality rate (40), except when it
  is associated with IV drug use.
• Endocarditis due to streptococci has a mortality
  rate of approximately 10.
• Prognosis largely depends on whether or not
  complications develop.

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Competency Exam
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Question One

• 1) Signs of systemic septic emboli are associated
  with
• Pulmonic valve vegetations
• Mitral valve vegetations
• Tricuspid valve vegetations
• Aortic valve vegetations
• All valves of the heart

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Question One

• 1) Signs of systemic septic emboli are associated
  with
• Pulmonic valve vegetations
• Mitral valve vegetations
• Tricuspid valve vegetations
• Aortic valve vegetations
• All valves of the heart

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Question Two

• 2) All are true of IV drug use-induced
  endocarditis, except
• Involves tricuspid valve
• Involves the aortic valve
• Can be difficult to diagnosis
• Streptococci species is usually the etiologic
  organism
• There is usually no murmur on admission.

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Question Two

• 2) All are true of IV drug use-induced
  endocarditis, except
• Involves tricuspid valve
• Involves the aortic valve
• Can be difficult to diagnosis
• Streptococci species is usually the etiologic
  organism
• There is usually no murmur on admission.

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Question Three

• 3) Pulmonay embolic phenomena strongly suggest
• Pulmonic valve disease
• Mitral valve disease
• Tricuspid valve disease
• Aortic valve disease
• Does not involve any heart valves

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Question Three

• 3) Pulmonay embolic phenomena strongly suggest
• Pulmonic valve disease
• Mitral valve disease
• Tricuspid valve disease
• Aortic valve disease
• Does not involve any heart valves

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End of Lecture

• Thank you for your attendance.
• This lecture will be made available at the
  Internal Medicine Residency website
• http//IM.official.ws