Echocardiography in Infective Endocarditis: A High Hit Rate at Te Whatu Ora – Waitaha Canterbury

Abstract

To evaluate the utility of echocardiography in General Medicine (GM) patients referred with possible infective endocarditis at Christchurch Hospital. Over a 6-month period between 1 January and 30 June 2021, all General Medicine in-patients who underwent echocardiography for any indication were screened to find those with possible infective endocarditis as an indication. This study reviewed the result of each echocardiogram and followed each patient over a 12-month period to determine the rate of infective endocarditis as the primary outcome. Secondary outcomes were the microbiological characteristics of those with infective endocarditis and operative rates. Of 262 GM patients who underwent echocardiogram during the study period, 88 (34%) patients were referred with possible endocarditis. Nineteen of 88 (22%) patients had definite or presumed infective endocarditis as a discharge diagnosis, comprising 12 (14%) patients with definite infective endocarditis, six patients with high clinical suspicion and non-diagnostic imaging who were treated as presumed endocarditis, and one patient with negative imaging subsequently readmitted with subacute prosthetic valve endocarditis. Five patients required operative management. Most of the culture-positive endocarditis in this series (70%) were from Streptococcus species; one had Staphylococcus aureus endocarditis. Approximately one in three echocardiograms performed on General Medicine patients at Christchurch Hospital are for possible infective endocarditis. A significant proportion of these patients are subsequently diagnosed with infective endocarditis. Given the scarcity of echocardiography, a case could be made for increasing resources and research into clinical predictive factors, which could further improve diagnostic rates.