Biventricular and Multisystem Thrombosis in a Young Patient With Elevated Factor VIII: A Case Report.

Thrombosis in young adults without evident risk factors warrants investigation for underlying hypercoagulable states. We report the case of a 26-year-old male patient with a history of deep vein thrombosis (DVT), who presented with an extensive multisystem thrombotic cascade including acute limb arterial ischemia, bilateral pulmonary embolism, and bilateral renal vein thrombosis. Cardiac imaging revealed apical akinesis and a large biventricular thrombus with an ejection fraction of 41%. A comprehensive workup for thrombophilia identified a markedly elevated Factor VIII (FVIII) level as the only positive finding. This case underscores that high FVIII can drive a severe prothrombotic phenotype, leading to rare and devastating complications like biventricular thrombosis. The successful management with a multidisciplinary approach involving anticoagulation and antiplatelet therapy highlights the critical importance of early diagnosis to guide targeted therapy and prevent life-threatening recurrence.