154. Do I Really Need a Transesophageal Echo? Comparing Echocardiographic Modalities in Native Valve Infective Endocarditis due to Methicillin-Resistant Staphylococcus aureus.

Background Methicillin-resistant Staphylococcus aureus (MRSA) infective endocarditis (IE) is associated with high morbidity and mortality. Management commonly includes six-weeks of antibiotics and surgical intervention, if the patient has complications. Current guidelines recommend obtaining an echocardiogram. Transesophageal echocardiogram (TEE) is preferred over transthoracic echocardiogram (TTE). We wanted to evaluate the role of a TEE in changing management of MRSA IE. Methods A retrospective cohort of patients with MRSA IE was analyzed between January 2013 and July 2017 at a tertiary care facility in East Tennessee. Patients with prosthetic valves or cardiac devices were excluded. Demographic, echocardiographic, antibiotic, blood culture, mortality, and intravenous drug use data were collected (Figure 1). Results Seventy-eight patients met the inclusion criteria. TTE was performed on 73 patients while five patients proceeded directly to TEE. Of the 73 patients that had a TTE, 33 (45.2%) detected the presence of vegetation and 40 (54.8%) did not. Of the 33 patients with a positive TTE, 15 subsequently underwent TEE, confirming IE. Out of the 40 patients with a negative TTE, 34 underwent TEE, of which 22 (64.7%) showed a vegetation. (Figure 2). A total of ten patients (12.8%) from the study underwent surgery. Of these ten, three (30%) had a positive TTE only, with no subsequent TEE. Five (50%) had both a positive TTE and TEE, and two (20%) had a negative TTE but positive TEE. Conclusion Transthoracic echocardiogram was adequate to visualize vegetations in 45.2% of patients. Completing a TEE increased the sensitivity of visualizing a vegetation, but management was most often not altered. Only two patients (5%) with a negative TTE, but positive TEE proceeded to surgery because of the findings. This causes us to question whether a subsequent TEE needs to be pursued when a TTE is negative in the setting of definite or possible IE by the modified Duke criteria. Even if a vegetation is seen on TEE the patient would most likely receive the same treatment, 6 weeks of intravenous antibiotics, as if no vegetation was seen. Forgoing a TEE reduces risk to the patient of undergoing a procedure, and reduces costs to the healthcare system. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]