In left-sided native valve Staphylococcus aureus endocarditis, the presence of an intracardiac abscess and left ventricular ejection fraction <40% on echocardiography have been shown to be independent predictors of in- hospital mortality [45]. In this same group of patients, intracardiac abscess and valve perforation on echocardiography have been shown to be independent predictors of 1-year mortality [45]. One large retrospective study has shown that in low- to intermediate-risk patients using a strict negative criterion on TTE beyond the absence or presence of valvular vegetations increases the sensitivity and NPV of TTE (sensitivity: 98% versus 43%; NPV: 97% versus 87%) [46]. US Echocardiography Transesophageal TEE plays an important role in the evaluation of infective endocarditis [39]. It is used in suspected infective endocarditis to directly identify or exclude valvular vegetations, paravalvular abscess, and valvular regurgitation [47,48]. It is the most sensitive imaging technique for identifying vegetations, the presence of which is the hallmark for a definitive diagnosis of infective endocarditis [40]. Ultrasound (US) diagnosis of infective endocarditis provides better diagnostic accuracy than using clinical criteria alone [41]. TEE has been shown to have up to a 98.6% NPV in suspected infective endocarditis [49]. TEE has better sensitivity than TTE for detecting vegetations [40]. TEE has better sensitivity and accuracy than TTE for identifying paravalvular abscesses [40]. TEE is indicated for suspected infective endocarditis of prosthetic valves; it is significantly more accurate than TTE [40]. Authors of a review in 2010 noted that TEE has sensitivity and specificity of >90% for detecting intracardiac lesions associated with infective endocarditis [40]. Several studies evaluated the diagnostic value of TTE and TEE in relation to the pretest probability of infective endocarditis based on clinical assessment in pediatric [42] and adult [43] patients.
Infective Endocarditis. In left-sided native valve Staphylococcus aureus endocarditis, the presence of an intracardiac abscess and left ventricular ejection fraction <40% on echocardiography have been shown to be independent predictors of in- hospital mortality [45]. In this same group of patients, intracardiac abscess and valve perforation on echocardiography have been shown to be independent predictors of 1-year mortality [45]. One large retrospective study has shown that in low- to intermediate-risk patients using a strict negative criterion on TTE beyond the absence or presence of valvular vegetations increases the sensitivity and NPV of TTE (sensitivity: 98% versus 43%; NPV: 97% versus 87%) [46]. US Echocardiography Transesophageal TEE plays an important role in the evaluation of infective endocarditis [39]. It is used in suspected infective endocarditis to directly identify or exclude valvular vegetations, paravalvular abscess, and valvular regurgitation [47,48]. It is the most sensitive imaging technique for identifying vegetations, the presence of which is the hallmark for a definitive diagnosis of infective endocarditis [40]. Ultrasound (US) diagnosis of infective endocarditis provides better diagnostic accuracy than using clinical criteria alone [41]. TEE has been shown to have up to a 98.6% NPV in suspected infective endocarditis [49]. TEE has better sensitivity than TTE for detecting vegetations [40]. TEE has better sensitivity and accuracy than TTE for identifying paravalvular abscesses [40]. TEE is indicated for suspected infective endocarditis of prosthetic valves; it is significantly more accurate than TTE [40]. Authors of a review in 2010 noted that TEE has sensitivity and specificity of >90% for detecting intracardiac lesions associated with infective endocarditis [40]. Several studies evaluated the diagnostic value of TTE and TEE in relation to the pretest probability of infective endocarditis based on clinical assessment in pediatric [42] and adult [43] patients.