Holden Elisabeth, Bashir Ahmed, Das Ira, Morton Hugh, Steadman Christopher D, Nightingale Peter, Steeds Richard P, David Miruna D
Microbiology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
Cardiology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
J Antimicrob Chemother. 2014 Jul;69(7):1960-5. doi: 10.1093/jac/dku082. Epub 2014 Mar 27.
Infective endocarditis (IE) is a feared complication in up to 38% of cases of Staphylococcus aureus bacteraemia (SAB). BSAC guidelines recommend echocardiography in all cases of SAB. The aim of this study was to determine the incidence of IE in SAB using transoesophageal echocardiography (TOE) as the first step in diagnostic imaging. This study also sought to identify clinical predictors that could improve stratification of those with and without IE.
A guideline was implemented that any SAB resulted in the microbiology department (i) recommending that the patient be referred for TOE and (ii) notifying the echocardiography department, resulting in streamlined listing of the patient for TOE. All cases of SAB were then assessed prospectively at University Hospitals Birmingham NHS Foundation Trust between September 2011 and October 2012. Previously identified risk factors for complicated S. aureus bacteraemia were recorded.
There were 98 SAB episodes in total. TOE was performed in 58 (59%) with a further 22 episodes imaged by transthoracic echocardiography alone. IE was diagnosed overall in 13 (16%) cases investigated with echocardiography. No risk factor for IE other than presence of a cardiac device was detected in this group (P = 0.013).
The rate of IE found in SAB is high when TOE is performed first line. There are no clear risk factors to improve yield or the type of echocardiography to be performed. Echocardiography should be performed in all cases and TOE should be considered where it is expected to influence management, as long as local resources allow.
感染性心内膜炎（IE）是金黄色葡萄球菌菌血症（SAB）高达38%病例中令人恐惧的并发症。英国抗菌化疗学会（BSAC）指南建议对所有SAB病例进行超声心动图检查。本研究的目的是将经食管超声心动图（TOE）作为诊断成像的第一步，以确定SAB中IE的发生率。本研究还试图确定可改善有无IE患者分层的临床预测因素。
实施一项指南，即任何SAB病例都要让微生物科（i）建议患者接受TOE检查，以及（ii）通知超声心动图科，从而简化患者TOE检查的预约流程。然后在2011年9月至2012年10月期间，对伯明翰大学医院国民保健服务信托基金的所有SAB病例进行前瞻性评估。记录先前确定的复杂金黄色葡萄球菌菌血症的危险因素。
总共发生98次SAB发作。58例（59%）接受了TOE检查，另有22例仅接受了经胸超声心动图检查。在接受超声心动图检查的病例中，总体诊断出13例（16%）IE。该组中除了存在心脏装置外，未检测到其他IE危险因素（P = 0.013）。
当将TOE作为一线检查时，SAB中发现的IE发生率很高。没有明确的危险因素可提高检出率或确定应进行的超声心动图类型。只要当地资源允许，所有病例均应进行超声心动图检查，若预计会影响治疗管理，则应考虑进行TOE检查。
