702. Characteristics of Infective Endocarditis (IE) and Predictors of 90-day Mortality Among People Who Do and Do Not Inject Drugs with IE in Seattle, Washington

BACKGROUND: People who inject drugs (PWID) are at high risk for IE and account for a growing proportion of IE cases in the United States. We describe key characteristics of IE and predictors of 90-day mortality among people who do and do not inject drug at two large academic medical centers. METHODS: We used a string-searching and pattern-matching algorithm within all discharge (DC) summaries to query the electronic medical record (EMR) for cases of IE among adults ≥18 years of age at two academic medical centers in Seattle, Washington from December 1, 2013 to July 31, 2019. All cases were chart reviewed by a member of the study team to confirm a clinical diagnosis of IE and verify housing and PWID status, the latter defined as any injection drug use in the 3 months prior to admission. Microbiology and valve involvement were extracted from DC summaries and chart-reviewed where needed. Deaths were obtained from Washington state death index, which links to our EMR. Descriptive statistics were used to compare PWID and non-PWID with IE, and Kaplan-Meier log rank tests and Cox proportional hazard models were used to assess for predictors of 90-day mortality. RESULTS: We identified 387 patients with IE, 44% (n=166) of whom were PWID. When compared to non-PWID, PWID were younger (median age 33 vs. 55 years, p< 0.001) and more likely to be female (48% vs. 31%, p=0.001), homeless (41% vs. 9%, p< 0.001), have coagulase-positive Staphylococcal IE (69% vs. 32%, p< 0.001), and have right sided IE (66% vs. 26%, p< 0.001). Seventeen percent (n=64) of patients died within 90 days of admission, including 14% (n=23) of PWID and 19% (n=41) of non-PWID, with no difference in 90-day mortality between these groups (log-rank p=0.3). In univariate analyses, having left sided IE was the only predictor of 90-day mortality (HR 4.79, 95% CI 2.18 – 10.5). CONCLUSION: Despite PWID being significantly younger and having a much higher frequency of right sided IE, they had similar 90-day mortality to non-PWID in this contemporary, urban cohort of hospitalized IE patients. Table 1. Demographic Characteristics of People Who Do and Do Not Inject Drugs with Infective Endocarditis at Two Seattle Hospitals, 2014 – 2019 [Image: see text] DISCLOSURES: All Authors: No reported disclosures