ABSTRACT NUMBER: ESOC2026A1355 SEVERE POST-THROMBOLYSIS HYPOFIBRINOGENEMIA REVEALING CONGENITAL FACTOR VII DEFICIENCY: A CASE REPORT

Abstract Background and aims Severe hypofibrinogenemia is a rare but clinically significant complication of intravenous thrombolysis (IVT) with recombinant tissue plasminogen activator (rt-PA). Factor VII (FVII) deficiency is the most common among rare autosomal recessive bleeding disorders, often asymptomatic and diagnosed incidentally. We report a case of acute ischemic stroke in which severe post-thrombolysis hypofibrinogenemia unmasked a previously undiagnosed moderate congenital FVII deficiency. Methods We describe the clinical course, laboratory findings and management of a patient treated with IVT for acute ischemic stroke. Serial coagulation tests, including rotational thromboelastometry (ROTEM) and specific clotting factor assays were performed. Results A 62-year-old woman was admitted with sudden onset of weakness and ataxia of the right side. Her medical history included paroxysmal atrial fibrillation not on anticoagulation therapy. In absence of contraindications, rt-PA was administered. Two hours after IVT, blood tests showed undetectable fibrinogen level and ROTEM demonstrated absence of clot formation. Despite repeated fibrinogen concentrate infusions (total 6 g) and vitamin K, correction was only partial: fibrinogen increased modestly and PT/INR remained persistently prolonged with normal aPTT. No bleeding complications occurred and the patient achieved a complete neurological recovery. Further evaluation revealed FVII activity of 36%, consistent with moderate congenital deficiency, supported by family history. Fibrinogen levels normalized in the following days, whereas PT/INR prolongation persisted. Given concomitant atrial fibrillation and absence of hemorrhagic events, anticoagulation with dabigatran was initiated. Conclusions This case highlights the importance of a careful hemostatic monitoring after intravenous thrombolysis and atailored anticoagulation strategies in patients with unrecognized coagulation disorders. Conflict of interest Medici Mariarosaria: nothing to disclose.