Recurrent Endocarditis in Persons Who Inject Drugs

Background. Infective endocarditis (IE) is increasing among persons who inject drugs (PWID) and has high morbidity and mortality. Recurrent IE in PWID is not well described. Methods. This was a retrospective cohort study conducted between February 2007 and March 2016. It included adult inpatients (>= 18) at any of 3 tertiary care centers in London, Ontario, with definite IE based on the Modified Duke's Criteria. The objectives were to characterize recurrent IE in PWID, identify risk factors for recurrent IE, identify the frequency of fungal endocarditis, and establish whether fungal infection was associated with higher mortality. Results. Three hundred ninety patients had endocarditis, with 212/390 in PWID. Sixty-eight of 212 (32%) PWID had a second episode, with 28/212 (12%) having additional recurrences. Second-episode IE was more common in PWID (11/178 [6.2%] vs 68/212 [32.1%]; P < .001). Peripherally inserted central catheter (PICC) line abuse was associated with increased risk of recurrent endocarditis (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.01-3.87; P = .04). In PWID, fungal IE was more common in second episodes than first episodes (1/212 [0.5%] vs 5/68 [7.4%]; P = .004). Additionally, fungal infections were associated with mortality in second-episode IE in PWID with an adjusted OR of 16.49 (95% CI, 1.12-243.17; P = .041). Despite recurrent infection, likely due to continued drug use, there was a low rate of referral to addiction treatment (14/68 [20.6%]). Conclusions. PWID have a high risk of recurrent endocarditis, particularly in patients who abuse PICC lines. Fungal endocarditis is more common in second-episode endocarditis and is associated with increased mortality. Consideration of empiric antifungal therapy in PWID with IE history and suspected IE should be considered.