Objectives: Injection drug users (IDUs) develop more right-sided infective endocarditis (IE) than non-IDUs, but it is not known whether this risk is specific to any particular injected drug. This study reviews the clinical characteristics of IE in an urban population and examines the association of drug type with manifestations of IE.
Methods: A retrospective cohort of 247 cases of IE was analyzed. Demographic, clinical, microbiologic, and echocardiographic data were collected.
Results: Our cohort featured a 74% IDU rate, most with heroin. Staphylococcus aureus was the most prevalent organism. S. aureus IE was more likely to occur in IDUs versus non-IDUs (OR 5.5, p<0.0001). Enterococcus faecalis IE was less likely to occur in IDUs (OR 0.21, p=0.02). Tricuspid valve (TV) IE was more likely to occur in IDUs (OR 4.37, p=0.001), while mitral valve (MV) IE occurred less commonly in IDUs (OR 0.40, p=0.005). TV IE occurred more frequently in heroin users vs. IDUs not using heroin (OR 4.03, p=0.033).
Conclusions: The epidemiology of IE in this cohort is different from that reported recently in other cohorts, likely due to the high prevalence of IDU. Heroin use may underlie the association between IDU and right-sided endocarditis.