Injection Drug Use Endocarditis: An Inner-City Hospital Experience

BACKGROUND: There has been a rise in the incidence of injection drug use and associated infective endocarditis. METHODS: The clinical outcomes of 39 patients admitted with injection drug use–associated infective endocarditis were collected with a mean follow-up of 14 months. The outcomes were compared for patients treated medically with those undergoing surgical intervention. Results: The mean age was 39 ± 11 years; 54% were female. Thirty-two patients (82%) had native and 7 (18%) prosthetic infective endocarditis. The tricuspid valve was affected in 17 patients (43%), the mitral in 10 (26%), the aortic in 4 (10%), and multiple valves in 8 (20%). Sixteen (41%) patients underwent surgery, and 23 (59%) were treated with medical therapy. The indications for surgery included heart failure, systemic emboli, recurrent infection, and vegetation size ≥10 mm. Patients undergoing surgery had a higher rate of paravalvular abscess (25% vs 0%, P = 0.02), valve perforation (37% vs 11%, P = 0.04), and mitral valve involvement (44% vs 13%, P = 0.06), whereas medically treated patients had higher tricuspid valve involvement (61% vs 19%, P = 0.02). During follow-up, 26% of medical and 31% of surgical cohort patients died (P = 0.7). Mortality was highest (54%) among those who continued medical management despite an indication for surgery. Univariate predictors of mortality were age (odds ratio [OR] 1.09, 95% confidence interval [CI]: 1.01-1.17; P = 0.02), heart failure (OR 6.9; 95% CI: 1.24-37.49; P = 0.02), septicemia (OR 4.40; 95% CI:0.99-19.54; P = 0.05), and shock (OR 10.8; 95% CI: 1.68-69.92; P = 0.01). CONCLUSIONS: Despite contemporary therapy, patients with injection drug use–associated infective endocarditis remain at high risk of complications and poor clinical outcomes. These findings highlight the need for developing new care pathways and a team approach for effective management.