Enterococcus faecalis bacteraemia and infective endocarditis - what are we missing?

Enterococcus faecalis is an increasingly common cause of infective endocarditis, with a recent study by Dahl et al demonstrating a prevalence of 26% of IE when transoesophageal echo was routinely undertaken. Another study undertaken by Østergaard et al found that 16.7% of patients with E. faecalis bacteraemia developed endocarditis. Based on these findings we examined the rates of IE diagnosed in our own health board to determine if our current practice is potentially missing cases of IE and if we could improve our management of these bacteraemias.

All blood cultures in patients over 18 which were positive for E. faecalis from October 2017 to March 2022 were reviewed. We analysed the patient characteristics, clinical outcomes and included a follow up period of 6 months to assess for recrudescence and treatment failure.

The rate of patients with E. faecalis bacteraemia diagnosed with IE was 7.1%. If polymicrobial blood cultures were excluded this rose to 13.0%. Community acquisition, patient cardiac or immune risk factors, monomicrobial culture and multiple positive blood cultures all were associated with IE. 62.1% of patients with E. faecalis bacteraemia did not have an echocardiogram during their admission, due to a variety of reasons.

The lower reported rate of IE in our cohort may be explained by higher proportion of CVC related infections. However, given the low rates of echocardiography and poor correlation of echocardiography use with IE risk factors, it is likely that cases of IE are being missed, particularly in those with multiple risk factors. Despite this, there was no difference in one-year survival between those diagnosed with IE vs without IE. We have delivered education sessions and introduced a multidisciplinary team meeting to discuss infective endocarditis cases to address these issues.