Infective Endocarditis in People Who Inject Drugs—A 5-Year Follow-up: “I’ve Seen the Needle and the Damage Done”

Background Infective endocarditis (IE) among people who inject drugs (PWID) has been associated with better short-term outcome. Long-term outcome of PWID with IE is poorly known. Methods This retrospective population-based study included PWID with IE and non-PWID adults with community-acquired IE who were diagnosed and treated in Southern Finland between 2013 and 2017 and survived the initial IE episode. All patients were followed for 5 years. Data were collected on drug use, receipt of medications for opioid use disorder (MOUD), survival, and subsequent IE episode during follow-up. Results Seventy-five PWID with IE and 98 patients with community-acquired IE were included. Buprenorphine and amphetamine or other stimulant were the most used substances among PWID. Sixteen PWID received MOUD before onset of IE, and 33 received MOUD at the time of discharge. Most PWID (86%) received addiction specialist consultation during the hospitalization. Fifteen patients in the PWID IE group experienced a new IE episode within 5-year follow-up as compared with 5 patients in the non-PWID IE group (odds ratio [OR], 4.65; P = .003). One-year all-cause mortality was 4.0% (3/75) in PWID IE and 4.1% (4/98) in non-PWID IE. Five-year all-cause mortality was 18.7% (14/75) in PWID IE and 13.3% (13/98) in non-PWID IE (P = .399). In multivariate analysis of the whole group, injection drug use (OR, 12.2), female gender (OR, 2.62), and higher age-adjusted comorbidity index were independent factors associated with death during 5-year follow-up. Conclusions Long-term survival of PWID with IE is poor, and they are at increased risk of a new IE episode as compared with non-PWID with community-acquired IE. More efforts in the treatment of addiction are needed.