Abstract TP12: No Association Between Outcomes And Anti-Factor Xa Levels For Heparin Monitoring In Patients With Cerebral Venous Thrombosis

Abstract

Introduction: For patients with cerebral venous thrombosis (CVT), intravenous unfractionated heparin (UFH) is a cornerstone of anticoagulant therapy. Drawbacks of UFH include difficulty in reaching an optimal dose. Anti-factor-Xa (AFXa) assay is used to monitor UFH treatment. We sought to determine whether AFXa values are associated with outcomes in CVT. Methods: This pilot study included adults (≥18y) admitted to a CSC between 1/1/2018-12/31/2020 who were initially treated for CVT with low-intensity UFH drip and had at least one AFXa assay. AFXa therapeutic values were defined as 0.25 - 0.5 IU/mL. We examined percent of patients who became therapeutic within 24h of arrival, and time (hours) to reach therapeutic range. Outcomes included hospital LOS, bleeding event, and discharge disposition. Continuous data are presented as median (interquartile range). Significance was p<0.20. Results: 51 CVT patients were included. The hospital LOS was 5 (4-9) days, 40 (78%) patients were discharged home, and 7 (14%) developed a bleed; 4 bleeds required no action. The time to start UFH was 2h (1-6) from arrival and the time to the first AFXa assay was 8h (4-11) from arrival. AFXa were drawn 4 (2-8) times per patient. AFXa assays were performed within 24h for 45 (88%) patients and 30 (67%) patients were in the therapeutic range. There was no association between study outcomes and therapeutic AFXa ( Table 1 ). There was also no association between study outcomes and the time (h) to reach therapeutic range: discharge home vs. other location (11h vs. 14h, p=0.49), development of a bleed vs. no bleed (9h vs. 12h, p=0.44), and no correlation with hospital LOS (p=0.55). Conclusions: Most CVT patients were within the target AFXa range within 24h of arrival. The time to achieve therapeutic AFXa was not associated with better outcomes, although most patients had a favorable disposition and bleeding complications were infrequent.