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Otto et al 2020 ACC/AHA Guideline for the Management of Valvular Heart Disease

Circulation. 2021;143:e72–e227. DOI: 10.1161/CIR.0000000000000923 February 2, 2021 e159 CLINICAL STATEMENTS AND GUIDELINES

least 10 days were randomized to continuation of the usual course of intravenous antibiotics or discharge to ambulatory treatment with oral antibiotics. As part of the study protocol, patients were reassessed by TEE within 1 to 3 days of completion of their assigned treatment to confirm that the patient had a sufficient response to therapy. The primary outcome was a composite of all-cause mortality, unplanned cardiac surgery, embolic events, or relapse of bacteremia with the primary pathogen. At 6 months after antibiotic treatment completion, the switch to early oral antibiotic therapy was noninferior to traditional long-term intravenous therapy.51 10.	 IE in patients with S. aureus bacteremia frequently involves normal cardiac valves and is seldom accompanied by the physical stigmata of IE, rendering the diagnosis of the disease difficult. Reliance on physical examination findings and clinical stigmata is likely to result in underdiagnosis of S. aureus IE in a large number of cases. TEE is cost-effective to guide duration of therapy in patients with intravascular catheter– associated S. aureus bacteremia, patients with intracardiac electronic devices, or other patients at higher risk of IE (including those with previous prosthetic valve surgery) or associated complications. Despite early diagnosis and appropriate therapy, IE after S. aureus bacteremia is frequently associated with disabling and life-threatening sequelae. The overall mortality rate of S. aureus IE ranges from 19% to 65%. Other complications include HF (20%–50%), paravalvular cardiac abscesses (30%–40%), neurological manifestations (30%), and systemic embolization (40%).11,36,55,56 11.	 When compared with native valve endocarditis, prosthetic valve endocarditis is characterized by a lower incidence of vegetations (especially in mechanical prostheses) and a higher incidence of annular abscess and other paravalvular complications. Because cardiac auscultation may also be less revealing in prosthetic valve endocarditis and because ordinarily less virulent organisms may cause more anatomic destruction before culture or serological detection, early use of TEE in these high-risk patients is important. The sensitivity of TEE for detecting IE is lower with prosthetic valves than with native valves, so the importance of comparing serial echocardiographic studies is paramount to making the diagnosis.59,60 12.	 Electrocardiographic-synchronized, multidetectorrow CT is emerging as an important tool for noninvasive cardiac assessment and may be helpful in evaluating complications of IE. CT may also be indicated in right-sided IE to demonstrate the presence of septic pulmonary infarcts and abscesses. Although CT is less accurate than TTE and TEE for identifying valvular vegetation and valvular perforations, CT is useful for evaluating patients with equivocal findings on TEE and for evaluating complications in patients with suspected paravalvular infection. CT imaging is particularly useful in preoperative evaluation of patients with aortic valve IE to evaluate coronary artery and aortic involvement. In suspected prosthetic valve endocarditis, cardiac CT is less affected by the shadowing of mechanical valves or bioprosthetic valve sewing rings than is ultrasonography. CT also allows evaluation of the motion of mechanical valve occluders and provides visualization of thrombus or infective material limiting valve occluder motion. Additional imaging modalities, such as cardiac valvular fluoroscopy, can be an adjunct to other clinical and imaging information to detect the presence of obstructive disease in mechanical prosthetic valves affected by IE.61,64–68

13.	 Diagnosis of IE can still be a vexing undertaking. It has been shown that the use of 18F-fluorodeoxyglucose PET/CT at the initial presentation of patients with suspected prosthetic valve endocarditis increases the diagnostic capability of the Modified Duke Criteria. The inclusion of abnormal 18F-fluorodeoxyglucose cardiac uptake as a major criterion addition to the Modified Duke Criteria enabled a recategorization of 76% of patients with prosthetic valve endocarditis initially classified as “possible” IE on admission to the hospital to “definite” IE. This tool must be used in centers with great experience with the technology, as this imaging technique may also be prone to false-positive results because of sterile inflammation in implanted prosthetic valves. 18F-fluorodeoxyglucose PET/ CT may also be considered a complementary diagnostic tool for some patients with suspected native valve endocarditis.69–71 14.	 Because the frequency of IE among patients with S. aureus bacteremia is reported to be approximately 30%, with many cases not being clinically suspected, TEE may be considered in the setting of S. aureus bacteremia to rule out IE. Even in S. aureus bacteremia from a known extracardiac source, such as an infected joint or joint prosthesis, TEE might be considered, given known cases of seeding of valve tissue in this type of setting. Possible exceptions are patients who have no underlying cardiac predisposing conditions or clinical signs of IE whose fever and bacteremia resolve within 72 hours after removal of a likely

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