Prosthetic valve endocarditis

Abstract

Prosthetic valve endocarditis (PVE) complicates the clinical course of 1–6% of patients with prosthetic valves and it is one of the types of infective endocarditis with the worst prognosis. In early-onset PVE (that occurs within the first year after surgery), the microbiological profile is dominated by staphylococci. In late-onset PVE, the microorganisms are similar to native valve endocarditis. Clinical manifestations are very variable and depend on the causative microorganism. The diagnosis is established with the modified Duke criteria although they yield lower diagnostic accuracy than in native valve endocarditis. Transoesophageal echocardiography is the main imaging technique in everyday clinical practice in PVE as the sensitivity is higher than transthoracic echocardiography. The findings of other techniques, as cardiac computed tomography (CT), positron emission tomography/CT, or single-photon emission computed tomography/CT have been recently recognized as new major diagnostic criteria and can be very useful in cases with a high level of clinical suspicion and negative echocardiography. Empirical antibiotic treatment should cover the most frequent microorganisms, especially staphylococci. Once the microbiological diagnosis is made, the antibiotic treatment is similar to native valve infective endocarditis, except for the addition of rifampicin in staphylococcal PVE and a longer length (up to 6 weeks) of the treatment. Surgical indications are also similar to native valve endocarditis, heart failure being the most common and embolic prevention the most debatable. Prognosis is bad, and during the follow-up, a team experienced with endocarditis is needed. Patients with a history of PVE should receive antibiotic prophylaxis if they undergo invasive dental manipulations.