Infective endocarditis: transesophageal echocardiography in all or in selected cases? When is echocardiography highly predictive for complications?

Echocardiography is currently considered one of the most important tools in the diagnosis and treatment of infective endocarditis (IE). However, its use leaves a number of issues open. Since transthoracic echocardiography (TTE) cannot define structures and vegetations < 4 mm, transesophageal echocardiography (TEE), though more costly and invasive, is superior to TTE in the diagnosis of IE. TEE should be recommended immediately in patients with valve prostheses and in those with a native valve and an intermediate or high pre-test probability of disease. In patients with a low probability of disease, a completely negative examination without the slightest valvular anomaly practically excludes the likelihood of IE; however, the patient should still be followed up. In patients with a very low probability of disease, echocardiography is not necessary; instead, reassessment can be performed at some future time. Echocardiography has a high prognostic value in IE since it may reveal intracardiac complications due to this disease and contributes to a better understanding of the clinical complications. Moreover, echocardiography may also aid in the choice of surgery timing and thus modify the clinical progression of the disease. Large and extensive vegetations that are more mobile and soft are more closely associated with the development of complications and embolic events. Despite numerous reports, uncertainty surrounds the approach to treatment when echocardiography discloses vegetations at risk of embolization in uncomplicated IE and in the absence of other indications for surgery.