Choosing To Repair or To Replace

When valve repair is an option, it is preferred over replacement. Advanced technical skills and sufficient experience in complex repair procedures are crucial to achieve a high success rate of repair procedures. Valve reconstruction (repair) surgeries are more often feasible in the mitral or tricuspid position than in aortic valve. This is mainly due to larger leaflet sizes of the mitral and tricuspid valves (better tolerating partial tissue resection and suturing). The greater prevalence of...

Indications and Evaluation for Surgery

Generally speaking, major absolute indications for surgical intervention in IE include 2. persistent and or uncontrolled infection despite aggressive medical therapy, and Significant anatomical changes and complications caused by IE, such as aneurysm, fistula, and atrioventricular discontinuity, may also be considered an indication, as they usually indicate the imminent occurrence of hemodynamic compromise. Some authors have advocated other relative indications for surgery (Table 8.1) 2,5,11 ....

The Role of Surgery

Despite medical progress in the diagnosis and antimicrobial therapy of IE, more than half of patients with IE suffer a serious complication, and the mortality rate is unacceptably high 20 during the initial hospitalization and 40 at one year 485 . The major causes of death are structural complications and hemody-namic instability. As such, cardiac surgery, principally valve replacement, has become an important adjunct to medical therapy. Cardiac surgery is currently used in 25-50 of cases, and...

Perivalvular Abscess and Related Complications

The diagnosis of perivalvular abscess is more difficult in patients with prosthetic IE, because increased perivalvular thickness is a common finding in these patients even in the absence of IE. A previous study for comparison is useful in the assessment of these patients, and repeat studies in seven to ten days to look for evolutional changes as previously discussed with native valve IE remains very pertinent. Perivalvular abnormalities are common even in patients who have had early cardiac...

Fungal Endocarditis

Fungi are uncommon but emerging causes of infective endocarditis, most recently accounting for 1-10 of organisms isolated, including 10 of cases of prosthetic valve endocarditis 338 . Simplistically, fungi are classified as yeasts or moulds. Yeasts are facultatively anaerobic, unicellular, non-filamentous fungi that are typically spherical or oval in shape. The most common yeasts involved in fungal endocarditis (FE) are the Candida spp. 338,339 , although FE with the other opportunistic yeasts...

Appropriate Use of Echo and Suggested Approach to a Patient Suspected of Having Endocarditis

The meaning and significance of the term clinically suspected IE will vary between observers. The range may include patients with unexplained isolated fever as well as those with the classic findings of fever, new regurgitant murmur, embolic phenomenon, and persistent bacteremia. Jassal et al., at our institution, found significant variation between the assessment of probability of IE between the attending team and the research team 32 . The latter employed a standardized scoring system to...

Microbiologic Diagnosis Blood Cultures

Blood culture remains the single most important investigation in a patient suspected of having infective endocarditis. If appropriately collected prior to antibiotic administration, blood cultures can be expected to yield growth of the causative organism in over 90 of cases of infective endocarditis. Identification of the organism may allow the treating physician to determine the original source of bacteremia, and facilitates the choice of the appropriate therapeutic agent(s) and treatment...

The Elderly Epidemiology

Despite the fact that the incidence of infective endocarditis has not changed, recent studies have shown remarkable changes in the epidemiology and clinical features of the disease. In the 1950s, when rheumatic fever was prevalent, particularly during World War II and before the wide use of penicillin, the incidence of endocarditis was highest in patients aged 20-30 years old and only 5 of patients with endocarditis were over 60 years of age. More recent publications show that the incidence of...

Procedures Producing Bacteremia

High-risk procedures, in this context, are those procedures associated with a high incidence of bacteremia, with bacteremia acting as a surrogate marker for IE risk. There is much controversy, however, about the role of invasive procedures, especially dental procedures, as the causative event leading to IE. The evidence for causality of odontogenic bacteremia is circumstantial, based on a temporal relation between dental procedures and subsequent manifestation of disease, and the identification...

Assessing the Valves and Adjacent Structures

Structural cardiac lesions in IE include (a) lesions that existed prior to the onset of the disease and (b) new lesions caused by IE (Table 8.2). Preexisting lesions may include mitral valve prolapse, any valvular stenosis or insufficiency, congenital defects such as bicuspid aortic valve and residual lesions from previous IE, including those related to prosthetic valve implantations. Lesions caused by the current IE include vegetations (most frequent IE lesions), leaflet cusp perforation,...

Streptococal NVE

The nomenclature of the streptococci is complex. However, with respect to NVE, it is clinically useful to divide streptococci into the following categories 11,12,27,28 (1) oral (or viridans group) streptococci (2) S. bovis complex (3) nutritionally variant streptococci (4) S. pneumoniae and (5) beta-hemolytic streptococci. Oral (or Viridans Group) Streptococci The oral (or viridans group) streptococci are a heterogeneous group of streptococci that constitute a vital part of the normal flora of...

S aureus

S. aureus endocarditis occurs in four clinically distinct populations 158 intravenous drug users (IVDUs) patients with prosthetic valves patients with health-care-acquired (nosocomial or nosohusial) endocarditis and non-IVDU patients with community-acquired endocarditis. This chapter will focus on the latter group, as the former groups are discussed in other chapters. Recent studies have demonstrated that S. aureus has become the leading cause of endocarditis, accounting for approximately 30 of...

Principles of Medical Therapy

Infective endocarditis remains a relatively rare disease, with annual incidences ranging from 15 to 60 cases per million . Due to this low rate, good, prospective, randomized controlled trials assessing the benefits of various antibiotic regimens in the treatment of IE have been difficult to perform. Therefore, the principles of antimicrobial selection for IE are based on the understanding of the behavior of the causative pathogen, proper interpretation of antibiotic susceptibility testing, an...

Surgical Outcomes and Complications

Excellent surgical results can be achieved in situations where infection has been brought under control, IE is confined to a native valve, valve damage is amenable to repair or simple replacement, and the patient is relatively young without comorbidities. Table 8.3 summarizes factors that negatively affect morbidity and or mortality after surgical management of IE. Both short- and long-term results are less favorable following surgery for PVE as compared Figure 8.4. Various locations and...

Native Valve Endocarditis Detection of Vegetation

Endocarditis Small Vegitation

Vegetation is the hallmark of the disease and most frequently is attached to the upstream side of the cardiac valves. Unusual locations such as Table 7.1. Indications for Echocardiography in Infective Endocarditis Diagnosis in patients with medium to high likelihood of endocarditis Strong suspicion for culture negative endocarditis Persistent bacteremia with virulent organism and no known cause High-risk patients including patients with prior endocarditis, congenital heart disease or prosthetic...

Endocarditis Associated with Pacemaker Leads and Central Venous Catheters

Masses adherent to intracardiac catheters and leads are common even in the absence of IE. Thus, the diagnosis of IE in this clinical setting requires clinical correlation such as the use of the Duke criteria. Vegetations associated with pacemaker leads can occur either in the atrium or ventricle, ranging in size from less than 5 mm to over 20 mm 56 . Echo evidence of vegetation is present in the majority of patients with pacemaker lead IE. In addition to the typical shaggy, mobile, soft...

Prosthetic Valve Endocarditis Detection of Vegetation

Endocarditis can affect bioprosthetic or mechanical heart valves as well as indwelling central lines and pacemaker wires. Vegetations have a predilection to affect the sewing ring of both the bioprosthetic and mechanical valves, although the leaflets of the bioprosthetic valve can also be involved. The presence of new perivalvular regurgitation is generally indicative of IE. Echocardiographic evaluation of endocarditis in the setting of prosthetic valves can be more challenging due to the...

Key Points

Empiric therapy for the management of endocarditis in injection drug users IVDUs must target S. aureus particularly MRSA and should therefore contain an agent such as vancomycin which is effective against MRSA. 2. In addition to S. aureus and MRSA, Gram negative bacilli such as P. aeruginosa and fungi, such as Candida spp must be considered when initiating treatment of endocarditis in an IVDU. 3. For IVDUs with right sided endocarditis caused by methicillin susceptible S. aureus, a 2 week...

Community Acquired Native Valve Endocarditis

The common causes of native valve endocarditis are members of the normal flora of the skin, oropharynx, and the gastrointestinal and genitourinary systems. The vast majority of native valve endocarditis cases are caused by Staphylococcus and Streptococcus species. Several recent publications show that Staphylococcus aureus seems to have overtaken the viridans group Streptococci as the most common cause of native valve IE 3 . However, a Table 4.1. Microorganisms in Endocarditis by Decade Source...

Immunocompromised Patients and Health CareAssociated Endocarditis Epidemiology

As medical technology advances, more and more patients have prolonged hospitalizations, are subject to invasive procedures, receive high-dose chemotherapy and corticosteroids, spend more time in intensive care setups and have more central lines, intubations, catheters and other foreign objects inserted. These trends have caused an increase in nosocomial bacteremia and as a result an increase in nosocomial endocarditis. Cabell et al. 43 studied the demographic and microbiological changes that...

Systemic Pathology of Infective Endocarditis Table

Splenic Infarct Pathology

Systemic manifestations of IE may be due to generalized sepsis, immune reactions including immune complex disease or related to emboli or ischemia with organ atrophy, ischemia, or infarction. Classic peripheral stigmata of IE may not be evident with right-sided IE or with infections due to HACEK organisms 22 . Similar to all disseminated infections, IE related sepsis may present with fever or fever of unknown origin , leukocytosis, disseminated intravascular coagulation diC , adult respiratory...

Historical Perspective

Endocarditis, an inflammatory disorder of the endocardium, has been recognized by the anatomical pathologists for some time. Prior to the bacteriological era, however, the various types of endocarditic lesions could not be categorized as infectious or non-infectious. Austin Flint's chapter on endocarditis likely referred to rheumatic valvular heart disease rather than to infectious endocarditis 1 . However, he utilized the terms acute, subacute, and chronic in his description, and this...

Epidemiology

To determine the effect of HIV infection and other factors on infective endocarditis among IVDU Wilson et al. 36 examined the incidence of endocarditis according to HIV status in a cohort of IVDU. Endocarditis incidence 117 cases was higher among HIV-seropositive than HIV-seronegative IVDU 13.8 vs. 3.3 cases 1,000 person-years . Multivariate analysis of HIV-infected case patients revealed an inverse association between infective endocarditis and CD4 lymphocyte count OR for 200-499 cells mm3,...

Diagnostic Approach History and Physical Examination

Clubbing Endocarditis

In the tradition of Osler, the diagnosis of IE is apparent when patients present with the classical clinical findings. Unfortunately, most patients do not present in this classic manner and the diagnosis of IE is often difficult to establish. The main components history, physical exam, lab investigations, chest x-ray, electrocar diogram and blood cultures are the mainstays of clinical diagnosis and have led to diagnostic algorithms proposed by Pelletier, von Reyn, and the group from Duke...

Approach to Infective Endocarditis at Surgery or Autopsy

At surgery or autopsy examination of hearts, valves, and vascular prostheses, clinical suspicion that the patient has IE may or may not be present. The presence of unexpected but suspicious valvular lesions should prompt a proper workup for IE. Before immersion of the heart or resected valve in fixative, a thorough examination should be made to visualize all the valves and perivalvular structures. Sterile instruments should be used if a suspicious lesion is encountered Figure 2.1 . Since the...

Historical Perspectives

Historical perspectives are fraught with interpretation and bias. For this author, particular points of interest include recollections and reminiscence from almost 50 years of medical learning and practice, as an observer to both the science and the management of endocarditis and the personal triumphs and failures in the care of patients with endocarditis. Although these biases will be apparent in this review, my goal is to provide my perspective on what many regard as the most fascinating of...

Intravenous Drug Users IVDU

The majority of IE in the IVDU group is caused by Staphylococcus aureus, which is responsible for 50-75 of cases 20,21 . The streptococci and enterococci are the next-most-common organisms 7-10 , with small percentages caused by CoNS, Gram-negatives, and Candida species. Polymicrobial IE is relatively common in the IVDU population, occurring in up to 5 of cases. S. aureus most commonly causes right-sided tricuspid endocarditis in the IVDU setting. In the review of definite S. aureus native...

References

Endocarditis at the millennium. J Infec Dis 1999 179 Suppl 2 S360-5. 2. Griffin MR, Wilson WR, Edwards WD, et al. Infective endocarditis Olmsted County, Minnesota, 1950 through 1981. JAMA 1985 254 1199-1202. 3. Tleyjeh IM, Steckelberg JM, Murad HS, et al. Temporal trends in infective endocarditis A population-based study in Olmsted County, Minnesota. JAMA 2005 293 3022-8. 4. Anderson HJ, Staffurth JS. Subacute bacterial endocarditis in the elderly. Lancet 1955 i 1055-8....

Active Infective Endocarditis Pathology Table

Windsock Ductus Arteriosus

On gross examination, infected thrombi of variable size, commonly known as vegetations, are detected along the lines of valve closure or at the low pressure end of jet lesions 2,9 . They are usually gray, pink, or brown and are often friable Figures 2.1, 2.5 . They may be single or multiple and may affect more than one valve. Common sites are usually on the downstream side of the intracardiac high-velocity flow jets, such as the atrial side of the mitral valve or the left atrial endocardium in...

Perivalvular Lesions of Infective Endocarditis Table

Endocarditis Fistula

Extension of the valve infection into surrounding structures predicts a higher mortality, higher risk of significant heart failure, and the need for cardiac surgery 22 . In the early stage, perivalvular abscess is largely composed of inflammatory infiltrate, but at later stages necrosis and cavitation usually develop leading to destruction of perivalvular tissue 33 . Perivalvular abscess is not a static complication but is progressive and can evolve into serious perivalvular complications...