Comparing Sentinel Admission for Infective Endocarditis Among Patients With and Without Injection Drug Use: A Single Center Study

Background. Injection drug use (IDU) is a risk factor for infective endocarditis (IE). This study describes the differences in IDU-associated IE (IDU-IE) compared to non-IDU IE with the goal of informing clinical management as we face a national opioid epidemic. Methods. We performed a retrospective review of patients with a primary admission for IE at a large tertiary care center from 1 January 2007 to 30 June 2015. Patients who met the modified Duke's criteria for definite IE were included and stratified by IDU status. Information was collected regarding demographics, microbiology, site of infection, IE complications, cardiothoracic (CT) surgery intervention, and death. Results. Three hundred eighty-one patients were admitted with definite IE, of whom 103 (27%) had IDU-IE. The mean age in patients with IDU-IE was 35.4 years (33.3–37.4) versus 61.9 years (60.1–63.8) in non-IDU (p < 0.001). Patients with IDU-IE had more prior IE (22 [21.4%] versus 18 [6.5%], p = 0.003). Patients with IDU-IE had significantly less diabetes, renal dysfunction, and prior cardiac surgery. IDU-IE was more commonly caused by Staphylococcus aureus (67 [65%] versus 97 [34.8%], p < 0.001; figures). IDU-IE versus non-IDU IE was more frequently right-sided (35.0% versus 5.4%), more likely to involve both the left and right sides (9.7% versus 2.5%); rates of prosthetic valve involvement were similar (8.7% versus 16.2%). IDU-IE was more associated with vegetation >1 cm (61 [59.2%] versus 84 [30.2%], p < 0.001), systemic emboli (85 [82.5%] versus 135 [48.6%], p = 0.04), and resistant organisms (8 [7.8%] versus 8 [2.9%], p < 0.001). There was no difference in rates of hemodynamic compromise, perivalvular abscess, prosthetic valve dysfunction, or antibiotic failure. Among cases of IDU-IE, CT surgery was consulted in 74 (71.8%) versus 155 (55.8%) (p = 0.01) and surgery performed in 40 (38.8%) versus 79 (28.4%) (p = 0.06). The 1-year mortality in IDU-IE was 16 (15.5%) compared to 37 (13.3%) in non-IDU IE (p = 0.62). Conclusion. Despite significantly younger age, fewer medical comorbidities and fewer prior cardiac surgeries, 1-year mortality was similar for patients with IDU-IE and non-IDU IE. Further investigation is warranted to elucidate the impact of IDU on management of IE and whether additional interventions can improve clinical outcomes. Disclosures. All authors: No reported disclosures.