NCMP-31. RISK OF INTRACRANIAL HEMORRHAGE (ICH) IN PATIENTS WITH HIGH-GRADE GLIOMA (HGG) ON THERAPEUTIC LOW MOLECULAR WEIGHT HEPARIN (LMWH)

Venous thromboembolism (VTE) occurs in 20–30% of HGG patients. The potential increased risk of ICH with therapeutic anticoagulation complicates VTE treatment. Recent retrospective study reported a 3-fold increased risk of ICH with therapeutic anticoagulation. Our study examines whether the administration of LMWH for VTE treatment is associated with increased risk of ICH in HGG patients.

We performed a retrospective cohort study of HGG patients from 1/2005–8/2016. Patients in the LMWH group initiated treatment after VTE diagnosis. Blinded review of neuroimaging for ICH was performed. Patient characteristics were summarized using frequency for categorical variables and mean for continuous variables. For analysis of the primary end point, estimates of cumulative incidence (CI) of ICH were calculated using competing risk analysis with death as competing risk; significance testing was performed using the Gray’s test.

A total of 174 patients (100 men) were included, 88 (51%) in the LMWH group and 86 (49%) in non-LMWH group. Within the non-LMWH group, 22 (26%) patients developed VTE but were not treated with anticoagulation, while 64 (74%) patients did not develop VTE. A total of 34 ICH were recorded: 19 (56%) in LMWH group, 3 (9%) in non-LMWH with VTE, and 12 (35%) in patients without VTE.No significant difference was observed in the 1-year CI of ICH in the LMWH cohort and non-LMWH with VTE group (17% versus 9%; Gray’s test, p=0.36). Among patients without VTE, the 1-year CI of ICH was 13%; direct comparison to LMWH group was not performed due to different starting time point of events. CONCLUSIONS: Contrary to recent studies, our data do not suggest that therapeutic LMWH is associated with significantly increased risk of ICH in HGG patients.