How does the American Society of Echocardiography (ASE) recommend using echocardiography to assess the presence and severity of infective endocarditis?

From the Guidelines

The American Society of Echocardiography recommends using transthoracic echocardiography (TTE) as the first-line imaging modality in suspected infective endocarditis (IE), followed by transesophageal echocardiography (TOE) if TTE is negative or non-diagnostic, or if a prosthetic heart valve or intracardiac device is present, as stated in the 2015 ESC guidelines 1. The recommendation for TTE as the initial imaging modality is based on its non-invasive nature and ability to quickly assess for signs of IE, such as vegetations, valvular regurgitation, abscesses, and perforations. Key points to consider when using echocardiography to assess IE include:

• TTE should be performed first in suspected cases, with TOE used as a follow-up if TTE is negative but clinical suspicion remains high, or to better characterize findings 1.
• TOE is particularly important for prosthetic valve endocarditis due to its superior visualization capabilities, and is recommended in all patients with a prosthetic heart valve or intracardiac device 1.
• Serial echocardiographic examinations are recommended to monitor treatment response and detect complications, with repeat TTE and/or TOE suggested within 5-7 days if the initial examination is negative but clinical suspicion remains high, or as soon as a new complication is suspected 1. The use of echocardiography in assessing IE is crucial due to the high morbidity and mortality associated with the condition, and the need for precise assessment to guide antibiotic therapy and determine if surgical intervention is necessary, as emphasized in the 2015 ESC guidelines 1.

From the Research

Echocardiography in Infective Endocarditis

The American Society of Echocardiography (ASE) recommends using echocardiography to assess the presence and severity of infective endocarditis. The following are key points to consider:

• Echocardiography, including transthoracic and transoesophageal, plays a crucial role in the diagnosis and prognosis assessment of patients with infective endocarditis 2.
• Seven echocardiographic findings are major criteria in the diagnosis of infective endocarditis, including vegetation, abscess, pseudoaneurysm, fistulae, new dehiscence of a prosthetic valve, perforation, and valve aneurysm 2.
• Transoesophageal echocardiography should be performed in most cases of left-sided endocarditis to better define the anatomic lesions and to rule out local complications 2.

Diagnostic Accuracy of Echocardiography

The diagnostic accuracy of echocardiography for infective endocarditis is as follows:

• Transthoracic echocardiography has a sensitivity of 61% and specificity of 94% for detecting vegetations, with a negative likelihood ratio of 0.42 3.
• Transesophageal echocardiography is superior to transthoracic echocardiography for detecting vegetations, with a higher sensitivity and specificity 3.
• A negative transthoracic echocardiography result can be used to rule out infective endocarditis in patients without prosthetic valves, but a positive or indeterminate result requires further evaluation with transesophageal echocardiography 3, 4.

Prognostic Value of Echocardiography

Echocardiography is also useful for assessing the prognosis of patients with infective endocarditis:

• Echocardiographic predictors of poor outcome include presence of periannular complications, prosthetic dysfunction, low left ventricular ejection fraction, pulmonary hypertension, and very large vegetations 2.
• The size and mobility of vegetations are not predictive of embolic risk, according to some studies 5.