Infective endocarditis and rheumatic heart disease in the north of Australia.

BACKGROUND: To prevent infective endocarditis (IE), Australian guidelines recommend providing prophylactic antibiotics to Indigenous patients with rheumatic heart disease (RHD) prior to procedures which may cause bacteremia. In northern Australia RHD remains prevalent. We aimed to determine whether RHD is associated with an increased risk of IE, which risk factors are associated with IE, and the incidence and aetiology of IE.

METHODS: A retrospective review of IE patients who fulfilled modified Duke criteria at two tertiary centres in northern Australia.

RESULTS: 89 patients were reviewed. The rate of IE was 6.5/100,000 person-years. IE was more common in people with RHD (relative risk (RR) 58), Indigenous Australians (RR 2.0) and men (RR 1.7). RHD-associated IE was not confined to Indigenous Australians with 42% being non-Indigenous. The commonest risk factors for IE were intracardiac prosthetic material, injecting drug use and previous IE. One in five patients died.

CONCLUSIONS: In northern Australia the principle risk factor for IE is not RHD. Whilst RHD increased the risk of IE it was not restricted to Indigenous Australians. Current Australian recommendations of providing prophylactic antibiotics to Indigenous patients with RHD prior to procedures which may cause bacteremia may need to be broadened to include non-Indigenous patients.