Prognostic Value of Delta Fibrinogen for tPA-Related Intracranial Hemorrhage: A Prospective Emergency Department Cohort Study

Background : Intravenous thrombolysis is a cornerstone therapy for acute ischemic stroke; however, treatment-related intracranial hemorrhage (ICH) remains a major clinical challenge. Identifying early, practical biomarkers that may help predict post-thrombolysis hemorrhagic complications is of significant importance. This study aimed to evaluate whether early fibrinogen variation within the first three hours after intravenous tissue plasminogen activator (IV tPA) administration is associated with 24-hour ICH. Methods : This single-center prospective cohort study included adult patients treated with IV tPA between October 2023 and February 2025. Baseline fibrinogen and 3-hour post-treatment fibrinogen levels were obtained, and delta fibrinogen was calculated. Routine 24-hour cranial CT was used to detect ICH. Subtypes were classified as HI1, HI2, PH1, or PH2. ROC analysis was performed to assess diagnostic performance. Results : A total of 105 patients were analyzed, of whom 21 (20%) developed ICH. Delta fibrinogen decline was significantly greater in the ICH group compared with the non-ICH group (200 mg/dL vs. 48.25 mg/dL; p = 0.009). Subgroup analysis showed that parenchymal hematoma (PH1/PH2) was strongly associated with greater fibrinogen reduction (p = 0.03). ROC analysis yielded an AUC of 0.748 for predicting PH, with an optimal cut-off of 158 mg/dL (sensitivity 74.7%, specificity 80.0%). Patients with PH had significantly worse 3-month functional outcomes and higher mortality (p < 0.05). Conclusion : Early fibrinogen decline within the first three hours after IV tPA is significantly associated with 24-hour ICH, particularly parenchymal hematoma. Monitoring fibrinogen kinetics may enhance early risk stratification and support clinical decision-making in the post-thrombolysis period.