Use of Transthoracic Echocardiography in the Management of Low-Risk Staphylococcus aureus Bacteremia Results From a Retrospective Multicenter Cohort Study

作者：Showier Adrienne; Burry Lisa; Bai Anthony D; Steinberg Marilyn; Ricciuto Daniel R; Fernandes Tania; Chiu Anna; Raybardhan Sumit; Science Michelle; Fernando Eshan; Bell Chaim M; Morris Andrew M^*

来源：JACC: Cardiovascular Imaging , 2015, 8(8): 924-931.

DOI：10.1016/j.jcmg.2015.02.027

• bacteremia
• echocardiogram
• endocarditis
• Staphylococcus aureus

OBJECTIVES The aim of this study was to develop a prediction model to identify patients with low-risk Staphylococcus aureus bacteremia (SA8), in whom infective endocarditis (IE) can be ruled out based on transthoracic echocardiogram (TIE).
BACKGROUND S. aureus is a major cause of bacteremia and often leads to IE. Current guidelines recommend performing transesophageal echocardiography on all patients or treating all patients empirically with prolonged intravenous antibiotics; however, this approach is resource intensive, many physicians do not adhere to guidelines, and recent studies suggest that low-risk patients may not require transesophageal echocardiography.
METHODS We conducted a retrospective cohort study of 833 consecutive hospitalized patients with SAB from 7 academic and community hospitals in Toronto, Canada, over a 3-year period (2007 to 2010). Patients who received a TTE within 28 days of bacteremia (n = 536) were randomly divided into derivation and validation cohorts. Multivariable logistic regression analysis was used to determine high-risk criteria for IE in the derivation cohort, and criteria were then applied to the validation cohort to determine diagnostic properties.
RESULTS Four high-risk criteria predicted IE: indeterminate or positive TIE (p < 0.001), community-acquired bacteremia (p = 0.034), intravenous drug use (p < 0.001), and high-risk cardiac condition (p < 0.004). In the validation cohort, the presence of any 1 of the high-risk criteria had 97% sensitivity (95% confidence interval [CI]: 87% to 100%) and 99% negative predictive value (95% CI: 96% to 100%) for IE. The negative likelihood ratio was 0.05 (95% Cl: 0.007 to 0.35).
CONCLUSIONS A normal TTE ruled out IE in patients without community-acquired SAB, high-risk cardiac conditions, and intravenous drug use. This study provides evidence that clinical risk stratification combined with a normal TTE may be adequate to rule out IE in most patients with SAB.

• 出版日期2015-8