Infective endocarditis in drug addicts: role of HIV infection and the diagnostic accuracy of Duke criteria.

BACKGROUND: Intravenous drug users (IVDUs) are at increased risk of infective endocarditis. Moreover, HIV infection is common in IVDUs, with a reported prevalence of 40-90%. The clinical features of IVDUs with infective endocarditis and HIV infection may be peculiar. Few data have been reported on the diagnostic accuracy of Duke criteria in IVDUs with or without HIV infection, and a comparison of these two populations is lacking.

METHODS: The present study aimed to compare prospectively the clinical features of patients with infective endocarditis with or without HIV infection and to evaluate the diagnostic accuracy of Duke criteria in these patients. The study population consisted of 201 consecutive adult IVDUs with a suspected infective endocarditis (102 patients with HIV infection and 99 patients without HIV infection).

RESULTS: Infective endocarditis was the final diagnosis in 40 of 102 patients (38.2%) with HIV infection and in 55 of 99 HIV-negative patients (55.6%). Despite similar baseline features, longer vegetations were recorded in infective endocarditis without HIV infection (23.7 +/- 7.1 mm versus 13.6 +/- 6.8 mm; P = 0.001). Patients with infective endocarditis and HIV infection had a higher total mortality at 2 months (respectively 12.5% versus 1.8%; P = 0.09); almost all the deaths were recorded in patients with AIDS or a CD4 cell count below 200 per microl, and no deaths were recorded in patients with HIV infection and a CD4 cell count > 500 per microl.

CONCLUSIONS: Despite no identical clinical features, Duke criteria had a similar sensitivity, specificity and diagnostic accuracy in IVDUs with and without HIV infection.