Table 2.

Diagnostic Workup for Patients with Persistent MRSA Bacteremia

Diagnostic Test	Recommended?	Evidence Base	Comments
TTE	For all patients with MRSA bacteremia	Endocarditis is common among patients with persistent MRSA bacteremia and affects prognosis and treatment [0–0]	Noninvasive and readily available
TEE	For patients with negative TTE, or in all patients with prosthetic valve in place.	Better sensitivity than TTE for detection of vegetations, particularly involving prosthetic valves [3–3]	Clinical prediction rules such as VIRSTA and PREDICT can help quantify endocarditis risk and need for TEE [43]
PET/CT	For: prosthetic valve endocarditis prosthetic vascular grafts native valve endocarditis to rule out extracardiac metastatic foci	PET/CT at 7–14 days after SAB diagnosis associated with lower mortality in observational cohorts [36, 44, 45]	May be limited by availability; costs; false positive results in the first several months after prosthetic device placement
CT or MRI spine	For patients with back pain or sciatica syndromes	S aureus is the most common cause of vertebral osteomyelitis and merits prolonged antibiotic therapy [46, 47]
Ultrasound of vascular catheter sites	For patients suspected of septic thrombophlebitis (eg, indwelling vascular catheters)	Persistent bacteremia is a cardinal clue [48]	Readily available
Abdominal-pelvic CT	May identify occult intra-abdominal abscess (eg, renal, splenic)	Especially for patients with symptoms/signs referable to these anatomic sites	Readily available

Abbreviations: CT, computed tomography; MRI, magnetic resonance imaging; MRSA, methicillin-resistant Staphylococcus aureus; PET/CT, Positron emission tomography/computed tomography; SAB, Staphylococcus aureus bacteremia; TEE, transesophageal echocardiography; TTE, transthoracic echocardiography.