ABSTRACT NUMBER: ESOC2026A1478 CONCOMITANT CARDIAC AND PULMONARY RIGHT-TO-LEFT SHUNTS IN A YOUNG PATIENT WITH ISCHEMIC STROKE

Abstract Background and aims Paradoxical embolism is a major cause of ischemic stroke in young patients. Patent foramen ovale (PFO) and pulmonary arteriovenous malformations (PAVMs) are independent sources of right-to-left shunt; however, their coexistence is rare and may substantially increase embolic risk. We report a case illustrating the diagnostic and therapeutic challenges of this association. Methods Neurological assessment and multimodal cardiovascular and thoracic imaging were performed to determine stroke etiology. Results A 35-year-old man presented with an embolic myocardial infarction with non-obstructive coronary arteries (MINOCA) and was started on oral anticoagulation. Four months later, despite anticoagulation, he developed exertional facial asymmetry progressing to left upper-limb monoparesis. Brain magnetic resonance imaging revealed lacunar infarcts in the right internal capsule and lenticular nucleus. Transesophageal echocardiography demonstrated a high-flow tunneled PFO with multiple interatrial septal fenestrations. Bubble studies revealed early massive right-to-left shunting, and delayed contrast passage through the left pulmonary veins. Thoracic computed tomography angiography confirmed a left lower lobe PAVM. PFO closure was unsuccessful, followed by successful PAVM embolization. Autoimmune panel and thrombophilia testing were negative. Anticoagulation was discontinued, and antiplatelet therapy initiated. No further ischemic events occurred. Conclusions Ischemic events under anticoagulation in young patients should prompt evaluation for extracardiac right-to-left shunts. Identification and treatment of concomitant PAVM may be essential to prevent recurrent embolic events. Conflict of interest Vifranny Espaillat, Jose De los Santos, Ariel Jimenez, Marian Javier: nothing to disclose Figure 1 - belongs to Results Figure 2 - belongs to Results Figure 3 - belongs to Results