*3.2.2. Follow-up during medical therapy*

Working Groups in consultation with other key organizations, developed a scoring system graded from 1 to 9, with 7–9 being an appropriate echo referral, 4–6 uncertain, and 1–3

Imaging of native or prosthetic valves is considered most appropriate (grade 9) where endocarditis is clinically suspected and associated with positive blood cultures or a new murmur. In addition, TTE is indicated for reevaluation of IE if any of the following are present as follows: (a) high risk of progressive disease, (b) change in clinical status of the patient, and/

Inappropriate reasons for performing TTE include transient fever (without bacteremia or new murmur) and cases of transient bacteremia with a non-IE pathogen and/or documentation of noncardiovascular infection. Also, performing echocardiography for routine surveillance without complications or when findings would not change management, is considered

Appropriateness guidelines for the use of TEE are more generic and are not necessarily specific for endocarditis. The use of TEE is considered reasonable in the following situations: (a) it is anticipated TTE imaging would be suboptimal, (b) to assess for interval change, if it is likely to guide a change in therapy, (c) assess valvular structure for planned interventions, and (d) to diagnose endocarditis if moderate pretest probability in certain subgroups, such as staph-

Inappropriate indications include the following: (a) if TTE is likely to be diagnostic, (b) followup TEE, when anticipated it would not change therapy, and (c) to diagnose IE with a low pretest

The 2015 European Society of Cardiology (ESC) Guidelines on the management of IE provide an alternative set of guidelines on the appropriate use of echocardiography, grouped according to management stage of the illness [17]. A summary of the guideline is provided as follows:

Class I indications include the following: (a) TTE first line in suspected IE, (b) TEE if negative TTE or nondiagnostic but clinical suspicion of IE, (c) TEE if clinical suspicion of IE if prosthetic valve or cardiac device is present, (d) repeat TTE and/or TEE if initial examination negative

Class IIa indications include the following: (a) consider echo for *Staphylococcus aureus* bacteremia and (b) consider TEE in all suspected cases of IE regardless of TTE findings, unless high-

quality study of native right-sided uncomplicated infection.

ylococcal bacteremia or fungemia, prosthetic valves or intracardiac devices [28].

inappropriate [28]. A summary of the guideline is provided as follows:

or (c) new clinical findings on cardiac examination [28].

inappropriate and should be avoided [28].

*3.1.2. Transesophageal imaging*

**3.2. European-based guidelines**

but high-clinical suspicion.

probability [28].

*3.2.1. Diagnosis*

*3.1.1. Transthoracic imaging*

66 Contemporary Challenges in Endocarditis

A class I indication to repeat either TTE and/or TEE is recommended if a new complication is clinically suspected. Consideration to repeat the TTE and/or TEE without complication is given a class IIa indication. The reasoning relates to the possibility of detecting a clinically silent complication and the ability to monitor vegetation size. This class IIa recommendation suggests the frequency of serial imaging should be based on factors such as the initial pathology, type of organism, and the response to treatment.
