Prospective Cohort Study of Infective Endocarditis in People Who Inject Drugs.

Abstract Background Infective endocarditis (IE) in people who inject drugs (PWID) is an emergent public health problem. Objectives The purpose of this study was to investigate IE in PWID and compare it with IE in non-PWID patients. Methods Two prospective cohort studies (ICE-PCS and ICE-Plus databases, encompassing 8,112 IE episodes from 2000 to 2006 and 2008 to 2012, with 64 and 34 sites and 28 and 18 countries, respectively). Outcomes were compared between PWID and non-PWID patients with IE. Logistic regression analyses were performed to investigate risk factors for 6-month mortality and relapses amongst PWID. Results A total of 7,616 patients (591 PWID and 7,025 non-PWID) were included. PWID patients were significantly younger (median 37.0 years [interquartile range: 29.5 to 44.2 years] vs. 63.3 years [interquartile range: 49.3 to 74.0 years]; p  Conclusions A notable proportion of cases in PWID involve left-sided valves, prosthetic valves, or are caused by microorganisms other than S. aureus.