Patients with the highest risk of IE

Patients with a prosthetic valve or with prosthetic material used for cardiac valve repair. This also applies to transcatheter-implanted prostheses and homografts.

Patients with previous IE

Patients with untreated cyanotic congenital heart disease (CHD) and those with CHD who have postoperative palliative shunts, conduits or other prostheses.

 

Recommendations for prophylaxis of infective endocarditis in the highest-risk patients according to the type of at-risk procedure

There is no compelling evidence that bacteraemia resulting from respiratory tract procedures, gastrointestinal or genitourinary procedures, including vaginal and caesarean delivery, or dermatological or musculoskeletal procedures causes IE

Patients listed in Table 3 who undergo an invasive respiratory tract procedure to treat an established infection (i.e. drainage of an abscess) should receive an antibiotic regimen that contains an anti-staphylococcal drug.

In the case of an established infection or if antibiotic therapy is indicated to prevent wound infection or sepsis associated with a gastrointestinal or genitourinary tract procedure in patients described in Table 3, it is reasonable that the antibiotic regimen includes an agent active against enterococci (i.e. ampicillin, amoxicillin or vancomycin; only in patients unable to tolerate beta-lactams). The use of intrauterine devices was regarded as contraindicated, but this was based on low levels of evidence. Use of an intrauterine device is now considered acceptable, in particular when other contraceptive methods are not possible and in women at low risk of genital infections.

For patients described in Table 3 undergoing surgical procedures involving infected skin (including oral abscesses), skin structure or musculoskeletal tissue, it is reasonable that the therapeutic regimen contains an agent active against staphylococci and beta-haemolytic streptococci.

 

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Recommendations for antibiotic prophylaxis for the prevention of local and systemic infections before cardiac or vascular interventions

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  • First, IE is not a single disease, but rather may present with very different aspects depending on the first organ involved, the underlying cardiac disease (if any), the microorganism involved, the presence or absence of complications and the patient's characteristics.8 No single practitioner will be able to manage and treat a patient in whom the main clinical symptoms might be cardiac, rheumatological, infectious, neurological or other.

  • Second, a very high level of expertise is needed from practitioners from several specialties, including cardiologists, cardiac surgeons, ID specialists, microbiologists, neurologists, neurosurgeons, experts in CHD and others. Echocardiography is known to have a major importance in the diagnosis and management of IE. However, other imaging techniques, including magnetic resonance imaging (MRI), multislice computed tomography (MSCT), and nuclear imaging, have also been shown to be useful for diagnosis, follow-up and decision making in patients with IE.10 Including all of these specialists in the team is becoming increasingly important.

  • Finally, about half of the patients with IE undergo surgery during the hospital course.54 Early discussion with the surgical team is important and is considered mandatory in all cases of complicated IE [i.e. endocarditis with heart failure (HF), abscess or embolic or neurological complications].

 

 

Diagnosis

Up to 90% of patients present with fever, often associated with systemic symptoms of chills, poor appetite and weight loss. Heart murmurs are found in up to 85% of patients. Up to 25% of patients have embolic complications at the time of diagnosis. Therefore IE has to be suspected in any patient presenting with fever and embolic phenomena. Classic signs may still be seen in the developing world in subacute forms of IE, although peripheral stigmata of IE are increasingly uncommon elsewhere, as patients generally present at an early stage of the disease. However, vascular and immunological phenomena such as splinter haemorrhages, Roth spots and glomerulonephritis remain common. Emboli to the brain, lung or spleen occur in 30% of patients and are often the presenting feature.58 In a febrile patient, diagnostic suspicion may be strengthened by laboratory signs of infection, such as elevated C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR), leucocytosis, anaemia and microscopic haematuria. However, these signs lack specificity and have not been integrated into current diagnostic criteria. Atypical presentation is common in elderly or immunocompromised patients,59 in whom fever is less common than in younger individuals. A high index of suspicion and low threshold for investigation are therefore essential in these and other high-risk groups, such as those with CHD or prosthetic valves, to exclude IE or avoid delays in diagnosis.

Sepsis severity may be indicated by the demonstration of a number of laboratory investigations, including the degree of leucocytosis/leucopoenia, the number of immature white cell forms, concentrations of CRP and procalcitonin, ESR and markers of end-organ dysfunction (lactataemia, elevated bilirubin, thrombocytopaenia and changes in serum creatinine concentration); however, none are diagnostic for IE.61 Further, certain laboratory investigations are used in surgical scoring systems relevant to risk stratification in patients with IE, including bilirubin, creatinine and platelet count [Sequential Organ Failure Assessment (SOFA) score] and creatinine clearance [European System for Cardiac Operative Risk Evaluation (EuroSCORE) II]. Finally, the pattern of increase in inflammatory mediators or immune complexes may support, but not prove, the diagnosis of IE, including the finding of hypocomplementaemia in the presence of elevated antineutrophil cytoplasmic antibody in endocarditis-associated vasculitis or, where lead infection is suspected clinically, the laboratory finding of a normal procalcitonin and white cell count in the presence of significantly elevated CRP and/or ESR.

The evaluation of patients with IE is no longer limited to conventional echocardiography, but should include several other imaging techniques such as MSCT, MRI, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) or other functional imaging modalities.

Compilation by Dr. Samad Ali Moradi, According to Duodecim Finnish cardiology reference book & ESC SCAD guideline & author work experience.