When TEE is needed in patients with staphylococcus aureus bacteremia for the assessment of risk profile of infective endocarditis?

Background: Echocardiography is the most important diagnostic technique for the diagnosis of endocarditis. in patients with Staphylococcus aureus bacteremia (SAB), a wide consensus about performing Trans-Thoracic (TTE) or Trans Esophageal Echocardiography (TEE) as first-line test currently lacks. Purpose: Recently a new score has been proposed to guide the use of TEE in this population. Our aim was to validate this new score in a clinical scenario. Methods: Data from 257 SAB patients admitted from 2012 to 2014 were collected. We tested the recently proposed Palraj’s scores to stratify patients’ risk for endocarditis. Moreover we analyzed our population to identify any other possible clinical predictor of IE not included in the score. Results: Endocarditis was diagnosed in 38 patients (18,5%). Palraj’s score showed to have a good effectiveness in the detection of patients with high risk of IE. By multivariable analysis we identified the presence of cardiac devices, the prolonged bacteremia and the intra-venous drug abuse (IVDA) as elements strongly correlated with IE. Following Palraj’s example, two scoring systems (day-1 and day-5) were derived, including IVDA as variable. Using a day-1 cut-off value =5 and a day-5 cut-off value =2 the "modified Palraj’s score" showed a sensitivity of 42,1% and 97% and a specificity of 88,6% and 32% for day-1 and day-5 scores respectively. Conclusions. Palraj’s scores are an effective scoring system to identify SAB patients with high risk for endocarditis. However the inclusion of IVDA in the criteria for the calculation of the scores improves their effectiveness in a normal population including drug abusers.