Infective endocarditis prosthetic valve

Infective endocarditis (IE) is a serious infection affecting the lining and valves of the heart. While this disease is mostly associated with infection of the heart valves, the septal defects may become involved as well. Infections also occur in patients with prosthetic or mechanical devices, such as mechanical heart valves or who are intravenous drug users (IVDUs). Bacteria is the primary cause of IE however, fungi and atypical organisms also can be responsible pathogens. 

Cardiac conditions in which prophylaxis is recommended include presence of prosthetic valves, prior infective endocarditis, congenital cardiac abnormalities, rheumatic heart disease or any other valvular dysfunction, hypertrophic... 

Prosthetic cardiac valves Previous infective endocarditis Congenital heart disease (CHD) ... 

In developed countries endocarditis is present in 1/1000 hospital admissions or 1-2 cases per million population. An increasing number of endocarditis cases are associated with intravascular device infections and the placement of prosthetic valves thus, endocarditis can be acquired during hospital stay. Men are afflicted more often than females, and most patients are >50 years of age. Pre-existing heart lesions predispose to bacterial endocarditis if they are accompanied by (thrombotic) alterations of the endocardial surface or blood flow such that bacteria... 

Rifampin is a first-line antitubercular drug used in the treatment of all forms of pulmonary and extrapul-monary tuberculosis. Rifampin is an alternative to isoniazid in the treatment of latent tuberculosis infection. Rifampin also may be combined with an antileprosy agent for the treatment of leprosy and to protect those in close contact with patients having H. influenza type b and N. meningitidis infection rifampin is also used in methicillin-resistant staphylococcal infections, such as osteomyelitis and prosthetic valve endocarditis. 

Rifampin combined with a second agent is used to eradicate staphylococcal carriage. Rifampin combination therapy is also indicated for treatment of serious staphylococcal infections such as osteomyelitis and prosthetic valve endocarditis. 

Rifampin is used in a variety of other clinical situations. An oral dosage of 600 mg twice daily for 2 days can eliminate meningococcal carriage. Rifampin, 20 mg/kg/d for 4 days, is used as prophylaxis in contacts of children with Haemophilus influenzae type b disease. Rifampin combined with a second agent is used to eradicate staphylococcal carriage. Rifampin combination therapy is also indicated for treatment of serious staphylococcal infections such as osteomyelitis and prosthetic valve endocarditis. Rifampin has been recommended also for use in combination with ceftriaxone or vancomycin in treatment of meningitis caused by highly penicillin-resistant strains of pneumococci. 

Prosthetic valves, particularly mechanical ones, are associated with thrombosis and embolism, and infective endocarditis. The overall risk of clinically evident embolism is 1-2% per annum in those taking anticoagulants (Vongpatanasin et al. 1996), with mitral valve prostheses being the most prone to thrombosis. 

Although prosthetic heart valves have been extensively and successfully anployed clinically, problems still exist during the postoperative period concerning thromboembolism. Infection and valvular Incompetence. Infectious prosthetic valve endocarditis (PVE) remains as a serious and potentially devastating consequence of valve replacement surgery with mechanically fabricated... 

Infective endocarditis (IE) is an uncommon infection usually occurring in persons with preexisting cardiac valvular abnormalities (e.g., prosthetic heart valves) or with other specific risk factors (e.g., intravenous drug abuse). 

Staphylococcal endocarditis is not a homogeneous disease appropriate management requires consideration of several questions, such as. Is the organism methicillin resistant Should combination therapy be used Is the infection on a native or prosthetic valve Does the patient have a history of IVDA Is the infection on the left or right side of the heart Another consideration in staphylococcal endocarditis is that some organisms may exhibit tolerance to antibiotics. However, similar to streptococci, the concern for tolerance among staphylococci should not affect antibiotic selection. ... 

Any patient who develops staphylococcal bacteremia is at risk for endocarditis. Many investigators have attempted to develop criteria that identify the bacteremic patient likely to have IE. In hospitalized patients with S. aureus bacteremia and an identified focus of infection, such as a vascular catheter, the risk of concomitant IE is low, and treatment of the bacteremia can be reduced to 2 weeks. This approach applies only if the patient does not have a prosthetic valve or additional clinical evidence for endocarditis. On the other hand, the following parameters predict higher risk of IE in patients with S. aureus bacteremia (1) the absence of a primary site of infection, (2) community acquisition of infection, (3) metastatic signs of infection, and (4) valvular vegetations detected by echocardiography. ... 

Fifty per cent of human infections are asymptomatic. The symptoms and signs of acute and chronic Q fever are described in Table 4.16. The chronic form of the disease occurs in around 5% of cases with ongoing symptoms of endocarditis for many years. Most patients who go on to develop this form of the disease have a pre-existing heart valve abnormality or a prosthetic valve. 

The other case involves the infection of a Beall prosthetic heart valve. Prosthetic valve endocarditis is a serious complication of cardiac valve replacement and may lead to high rates of mortality... 

Nearly every type of prosthesis used in humans has been associated with serious infections. These include orthopedic protheses (joint space or bone infections), prosthetic heart valves (endocarditis), vascular prostheses (graft infections and bacteremia), intraocular lens prostheses (endophthalmitis), hemodialysis (hepatitis, bacteremia and shunt site infections), cerebrospinal fluid shunts (ventriculitis), and all types of catheters. In many cases, fulminant infectious processes may be present in patients who present clinically with minimal signs and symptoms. 

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