Transthoracic echocardiography in children with Staphylococcus aureus bacteraemia: a multi-centre retrospective analysis

Background Staphylococcus aureus bacteraemia (SAB) is associated with risk of infective endocarditis (IE). IE is rare in children in the absence of known risk factors such as congenital heart disease. Routine transthoracic echocardiography (TTE) is often performed in children with SAB despite limited age-specific evidence. Methods This multi-centre retrospective cohort study included 101 children (aged ≤18 years) with SAB across six North West London hospitals (2018–2023). Data were collected from electronic patient records. Results 71 children (70%) underwent TTE and 30 (30%) did not. IE was confirmed in four (5.6%) of those undergoing TTE. All four IE cases were right-sided and occurred in children with established risk factors: congenital heart disease (2/4), intravenous drug use (1/4) or central venous catheters (2/4). The TTE group had longer hospital stays than the no-TTE group (median 17 vs 4 days, p=0.0020). Acute in-hospital mortality occurred in 1/71 of the TTE group vs 0/30 of the no-TTE group (p=1.0). Among children undergoing TTE, features associated with IE included embolic phenomena (75% vs 1.5%, p<0.001), higher CRP (median 237 vs 124 mg/L, p=0.083), persistent bacteraemia at >72 hours (67% vs 4.9%, p=0.018) and polymicrobial growth on blood culture (50% vs 6%, p=0.033). Conclusion Our findings support a risk-stratified rather than universal approach to TTE in paediatric SAB. TTE could reasonably be omitted in children with a structurally normal heart, no established IE risk factor and no clinical feature suggestive of IE, but should be performed when embolic phenomena, persistent bacteraemia, polymicrobial growth, a pre-existing murmur or an established IE risk factor is present. Prospective multi-centre validation is needed before such an approach can be adopted in routine practice.