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

Introduction

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

Native Valve Endocarditis

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.

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.

Prosthetic Valve Endocarditis

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.

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.

Endocarditis and IV Drug Use

Endocarditis and IV Drug Use Commonly involves the tricuspid valve. S. aureus is the most common causative organism.

Pathophysiology

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.

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.

Frequency

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.

Mortality / Morbidity

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.

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.

Gender / Age

Gender / Age Gender: Age: The male-to-female ratio is approximately 2:1 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.

Clinical Aspects

History

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

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.

History (Other) Other common complaints include: Anorexia Weight loss Malaise Headache Myalgias Additional common complaints include: Night sweats Shortness of breath Cough Joint pains

Physical

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.

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.

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.

Petechiae

Splinter Hemorrhages

Osler Nodes

Osler Nodes

Janeway lesions

Roth Spots

Physical (Other) Other findings: Additional findings: Splenomegaly Stiff neck Delirium Paralysis Hemiparesis Aphasia Conjunctival hemorrhage Additional findings: Pallor Gallops Rales Cardiac arrhythmia Pericardial rub Pleural friction rub

Causes

Causes: Native Valve

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%)

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.

Causes: Prosthetic Valve

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.

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.

Causes: IV Drug Use

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.

Causes: IV Drug Use S. aureus is the most common (<50% of cases) etiologic organism. Other causative organisms include streptococci, fungi, and gram-negative rods (eg. Pseudomonads, Serratia species).

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.

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

Differentials

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

Workup

Lab Studies Send baseline studies: CBC Electrolytes Creatinine BUN Glucose Coagulation Panel

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.

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.

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.

Vegetation on Mitral Valve

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.

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.

Treatment

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.

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

Medication

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.

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.

Follow-up

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

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

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

Complications

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

Prognosis

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.

Competency Exam

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

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

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.

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.

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

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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