Harm Reduction for Injection Drug Users with Infective Endocarditis: A Systematic Review

Background: Infective endocarditis in the setting of injection drug use (IDU-IE) can be managed medically and surgically, but the greatest risk to short-term survival are complications of continued use. Despite this, harm reduction interventions have not been widely adopted in inpatient settings for individuals with IDU-IE. Objectives: The aim of this systematic review was to determine the types, effectiveness, and availability of targeted harm reduction interventions for individuals with IDU-IE. In this review, harm reduction was defined as any practice aimed at reducing negative consequences associated with substance use. Methods: In accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) Guidelines, 5 electronic databases were systematically searched to identify studies targeting harm reduction interventions for individuals with IDU-IE. Study quality was appraised using the Cochrane Risk of Bias Tool. Key findings of studies were summarized descriptively as a quantitative meta-analysis could not be undertaken. Results: Four studies (involving 221 participants) met eligibility criteria. The mean age was 39.3 +/- 16.7 years, 69.8% were males and 80.7% had an opioid use disorder. Harm reduction interventions included inpatient addictions consultations, needle hygiene interventions, and outpatient parenteral antibiotic therapy. Such interventions were associated with decreased morbidity and mortality for individuals with IDU-IE: 19% of patients receiving inpatient addictions consultation subsequently accepted residential treatment, 38% engaged in follow-up, and monthly illicit opioid use was lowered from 16.5 days to 1.5 days. Six-month mortality was 7.1%. Of the patients who received outpatient parenteral antibiotics, 93% did not experience any recurrent infections during follow-up and there were no patient deaths. Needle hygiene interventions reduced the rate of bacterial infections over a 6-month follow-up period (hazard ratio: 0.80; 95% confidence interval, 0.37-1.74). Conclusion: Harm reduction interventions are potentially effective means for reducing morbidity and mortality in patients with IDU-IE.