# Characteristics of Infective Endocarditis in Intravenous Drug Users vs. Non-Users: A Retrospective Study Conducted in Bucharest, Romania

## TL;DR

This study compares infective endocarditis in drug users and non-users in Romania, finding that drug users face more severe complications and worse long-term outcomes.

## Contribution

The study provides new insights into IE characteristics among intravenous drug users in Eastern Europe, where data are scarce.

## Key findings

- PWID were younger, more male, and had higher HIV and HCV rates compared to non-PWID.
- PWID had more right-sided IE, larger vegetations, and higher S. aureus prevalence, while non-PWID had more left-sided disease and prosthetic valve involvement.
- PWID experienced more embolic complications and had higher 12-month mortality than non-PWID.

## Abstract

Background and Objectives: Infective endocarditis (IE) remains a severe infection with high morbidity and mortality, particularly among people who inject drugs (PWID). Data from Eastern Europe are limited, despite the increasing burden of intravenous drug use in the region. Materials and Methods: We conducted a retrospective, observational cohort study of 153 patients diagnosed with IE and admitted to the “Dr. Victor Babeș” Clinical Hospital for Infectious and Tropical Diseases in Bucharest, Romania, between August 2019 and July 2024. Patients were classified into PWID (n = 51) and non-PWID (n = 102). Clinical characteristics, microbiological profiles, echocardiographic findings, complications, and outcomes (in-hospital, 10-week, and 12-month mortality) were compared between groups. Results: PWID were significantly younger (mean 34.0 ± 6.6 years vs. 64.3 ± 13.1 years; p < 0.001), predominantly male (86.3% vs. 62.7%; p = 0.003) and had higher rates of HIV (64.7%) and HCV (98.1%). Right-sided IE and larger vegetations were more common in PWID, whereas non-PWID had more left-sided disease, pre-existing valvular pathology, and prosthetic valve involvement. Staphylococcus aureus predominated in PWID (68.6% vs. 27.5%; p < 0.001), while non-PWID had more Streptococcus spp. and Coxiella burnetii cases. Embolic complications, particularly pulmonary emboli, and valvular rupture were significantly more frequent in PWID, while non-PWID had higher rates of heart failure and surgical interventions. In-hospital mortality was similar (17.6% vs. 11.8%; p = 0.318), but 12-month mortality was higher in PWID (27.5% vs. 13.7%; p = 0.038). Conclusions: IE in PWID shows a distinct clinical and microbiological profile, with more aggressive complications and worse long-term survival. Tailored management, early diagnosis, harm reduction programs, and dedicated follow-up are urgently needed in this high-risk population.