Early vs. late enoxaparin for the prevention of venous thromboembolism in patients with ICH: A double blind placebo controlled multicenter study

•Venous thromboembolism in paralyzed ICH patients is nowadays very rare, if prophylaxix guidelines are followed strictly.•This double blind study shows that it is safe to administer low molecular heparins to ICH patients as early as 24 h after the onset of symptoms. Venous thromboembolism (VTE) after primary intracerebral hemorrhage (ICH) worsens patient prognosis. Administering low-molecular weight heparins (LMWH) to prevent VTE early (24 h) may increase the risk of hematoma enlargement, whereas administering late (72 h) after onset may decrease its effect on VTE prevention. The authors investigated when it is safe and effective to start LMWH in ICH patients. In the setting of double blinded, placebo controlled randomization, patients >18 years of age with paretic lower extremity, and admitted to the emergency room within 12 h of the onset of ICH, were randomized into two groups. Patients in the enoxaparin group received 20 mg twice a day 24 h (early) after the onset of ICH and in the placebo group 72 h (late) after onset respectively. Both groups immediately received intermittent pneumatic compression stockings at the ER. Patients were prospectively and routinely screened for VTE and hemorrhagic complications 1 day after entering the study and again before discharge. 139 patients were included for randomization in this study. Only 3 patients developed VTE, 2 in the early enoxaparin group and one in the late enoxaparin group. No patients developed PE. Thromboembolic events (p = 0.901), risk of hematoma enlargement (p = 0.927) and overall outcome (P = 0.904) did not differ significantly between the groups. Administering 40 mg/d LMWH for prevention of VTE to a spontaneous ICH patient is safe regardless of whether it is started 24 h (early) or 72 h (late) after the hemorrhage. Risk of hemorrhage enlargement is not associated with early LMWH treatment. Administering LMWH late did not increase VTEs.