Systemic Embolic Events in People Who Inject Drugs with Patent Foramen Ovale and Right-sided Infective Endocarditis: A Systematic Review

Abstract Objectives Knowing the prevalence of patent foramen ovale (PFO) and recognizing the increasing number of people who inject drugs (PWID) with right-sided infective endocarditis (RSIE), we aimed to better characterize the syndrome of injection drug use, RSIE and PFO with systemic embolic events. Methods A systematic search across multiple databases was independently screened using predefined criteria (from inception until September 2025). Published cases of adult PWID diagnosed with RSIE and ischemic stroke or other systemic embolic event were included, provided they had PFO assessment. Individuals were excluded if they had CIED infections or any other conditions associated with systemic or paradoxical embolism. Results The systematic review identified 13 studies with 14 young patients, mostly without comorbidities, predominantly infected with Staphylococcus aureus. In most cases, echocardiography revealed large tricuspid valve vegetations. Neuroimaging confirmed multiple ischemic infarcts, while 5 patients showed emboli outside the central nervous system (4 of them as the only systemic embolic event). At least 11 (79%) patients had echocardiographic evidence of right-to-left shunting. Management included cardiac surgery in 6 cases that involved valve replacement or repair, percutaneous PFO closure in 2 cases and percutaneous mechanical aspiration in 1 case. Three patients (21%) died during hospitalization and only 27.3% patients had outpatient follow-up. Conclusions RSIE with systemic embolism in PWID with PFO has rarely been reported, affects younger patients without sex predominance, and was usually due to S. aureus with large tricuspid vegetations. Right-to-left shunting was characteristic and outcomes were relatively poor despite combined medical, surgical and interventional therapies.