Infective Endocarditis: A Retrospective Audit of Investigation and Management of at Risk Patients

Aim: Determine adherence to local and international guidelines for the management of potential infective endocarditis in a secondary care setting. Method: Database searches were performed for two sets of 100 consecutive patients; echocardiography requests for possible endocarditis and blood culture results positive for S. Aureus. Notes were reviewed to determine clinical details. Patients with inadequate data were excluded. Results: 100 echocardiography requests for possible endocarditis were identified. No patients were excluded. Blood cultures were drawn prior to antibiotics in 77 patients. Echocardiography requests followed guidelines in 89 patients. All nine patients with no pre-echo Modified Duke criteria all had normal echocardiography. Endocarditis was diagnosed in 19 patients, two were culture negative. 95 patients were identified with blood cultures positive for S. Aureus. 23 patients were excluded. S. Aureus bacteraemia was complicated by endocarditis in 8% of patients and had a one year mortality of 32%. Repeat cultures were not performed in 35 patients. Guideline recommended echocardiography not performed on 41 patients. Conclusion: Echocardiography may be overutilized in low risk patients. S. Aureus bacteraemia was associated with a lower incidence of endocarditis than previously reported. As echocardiography of high risk patients did not meet guideline recommendations this may indicate missed diagnoses. Cultures negative endocarditis had higher incidence than in previously published New Zealand data. This study is limited by its retrospective nature but increased adherence to guidelines may increase diagnosis of endocarditis and reduce culture negative results.