Infective endocarditis in intravenous drug abusers

Abstract

Infective endocarditis (IE) is one of the most severe complications in intravenous drug abusers (IVDA). IE usually involves the tricuspid valve, Staphylococcus aureus is the most common etiologic agent, and it has a relatively good prognosis. Currently, between 40% and 90% of IVDA with IE are HIV infected, and the HIV epidemic has caused a decrease in the incidence of this disease, probably due to changes in drug administration habits undertaken by addicts in order to avoid HIV transmission. This review focuses on progress made over the past few years in some aspects of IE in IVDA. The pathogenesis of tricuspid endocarditis is still unknown more than 60 years after the first series. The most important advance in antibiotic therapy is that noncomplicated S. aureus right-sided endocarditis can be successfully treated with an intravenous 2-week course of nafcillin or cloxacillin plus an aminoglycoside, although probably the aminoglycoside administration could be stopped after the first 3 to 5 days. Surgery in HIV-infected IVDA with IE does not worsen the prognosis. Considering the possibility of reinfection in IVDA, prosthetic material is usually avoided. Tricuspid valvulectomy or valve repair should be considered the technique of choice in IVDA with right-sided IE. Replacement of the tricuspid valve by a cryopreserved mitral homograft is the latest introduction into clinical practice. It provides atrioventricular competence, thereby avoiding late right heart failure. Reinfections can be treated medically with a negligible reoperation rate. Overall mortality for HIV-infected or non-HIV-infected IVDA with IE is similar. However, among HIV-infected IVDA, mortality is significantly higher in those who are most severely immunosuppressed, with CD4(+) cell counts below 200/L or with AIDS criteria.

Infective Endocarditis and Rheumatic Heart Disease in the North of Australia

“…The microbiologic aetiology of IE in our study was comparable to that seen in other Australian and international studies [2,22,24,25]. In line with previous studies, IDUassociated IE was more likely to be caused by S. aureus [26].…”

Long-term Outcome of Infective Endocarditis in Non-Intravenous Drug Users

“…Second, in the singular profile of patients who have endocarditis and are also IVDUs, they have a younger mean age and different clinical features, site of involvement, and bacteriologic findings, with a higher prevalence of HIV and tricuspid valve IE, of which Staphylococcus aureus is the etiologic agent, compared with non-IVDUs. 7 All survivors of the in-hospital phase were included in our prospective follow-up cohort. Follow-up data were obtained for each patient at the 1-, 2-, 3-, and 4-year postdischarge times by reviewing the patient's charts and by conducting telephone interviews with the patient or family members.…”

Infective endocarditis in intravenous drug users: a review article

“…As previously stated, only 13% of IE occurs on right-sided valves among all patient cohorts 6. However, a Spanish study of 1529 IVDUs with IE, over a 15-year period, found that 79% of cases were right-sided (with 16% left-sided and 5% mixed) 9. The reason for this vast difference is yet to be clarified but may be partly explained by behaviours surrounding injection in IVDUs.…”

“…In IVDUs, IE is normally right-sided with the tricuspid valve most commonly affected in 46%–78% of cases 1 9. Often there are no specific clinical signs to suggest tricuspid valve endocarditis as murmurs are frequently inaudible and the classical peripheral stigmata of IE (Osler nodes, splinter haemorrhages, Roth spots) and heart failure are very rare 1.…”