1024. First Episode Infective Endocarditis in Persons Who Inject Drugs (PWIDs); A Retrospective Cohort Study

Abstract

BackgroundPersons who inject drugs (PWID) represent a distinct demographic of patients with infective endocarditis (IE). Many centers do not perform valvular surgery on these patients due to concerns about poor outcomes.MethodsRetrospective cohort study comparing PWID patients to non-PWID patients presenting between February 2007 and March 2016 in London, Ontario, among adult (>18) inpatients with first episode IE.ResultsIn 370 first episode IE cases, 53.9% occurred in PWIDs. PWID patients were younger (35.4 SD 10.0 vs. 59.4 SD 14.9) (P < 0.001), more likely to have right-sided infection [125/202 (62%), vs. 16/168 (9.5%) (P < 0.001)], and more often due to S. aureus (156/202 (77.3%) vs. 54/168 (32.1%), P < 0.001). Myocardial and aortic root abscesses were less common in PWIDs [17/202 (8.4%) vs. 50/168 (30%) (P < 0.01)]. There was no difference in the frequency of noncardiac complications. In total, 36.5% of patients were treated surgically with PWID patients less likely to undergo surgery [39/202 (19.3%) vs. 98/168 (58%) P < 0.001]. Cox regression analysis identified the protective effect of cardiac surgery with regards to survival in all patients, with a hazard ratio of 0.49 (95% CI 0.31–0.76, P < 0.001), as well as among PWIDs (HR 0.39, 95% CI 0.17–0.87, P = 0.02). Among all patients, lower survival was associated with older age (HR 1.03, 95% CI 1.00–1.05, P < 0.001), injection drug use (HR 2.72, 95% CI 1.52–4.88, P < 0.001), left-sided infection (HR 3.48, 95% CI 2.01–6.03, P < 0.001), and bilateral infection (HR 3.19, 95% CI 1.45–7.01, P = 0.004). The lower survival of left-sided infection (HR 4.01, 95% CI 1.97–8.18, P < 0.001) or bilateral infection (HR 6.94, 95% CI 2.39–20.2,P < 0.001) was re-demonstrated in PWIDs.ConclusionThis study identifies important clinical differences between PWIDs and nondrug users with respect to valve involvement, causative organism, complications, and management strategies. Our results highlight the important role of surgical treatment in a carefully selected PWID patient population.Disclosures All authors: No reported disclosures.