Background — While warfarin-related intracranial hemorrhage (ICH) occurs in 0.25%-1.1% patients per year, little is known about the practice and outcomes of anticoagulant reinitiation.
Methods — The researchers studied a cohort of consecutive patients with warfarin-related ICH (intracerebral or subarachnoid) admitted to 13 stroke centres in the Registry of the Canadian Stroke Network between July 2003 and March 2008. The researchers examined patterns of warfarin reinitiation and variables associated with 30-day and 1-year outcomes.
Results — Among the 284 patients studied (mean age 74 ± 12 years), warfarin was restarted in-hospital in 91 patients (32%). Factors associated with restarting warfarin were lower stroke severity (adjusted odds ratio [aOR] 2.07, 95% confidence interval [CI]; 1.20-3.57, P = 0.009) or presence of valve prosthesis (aOR 3.07, 95% CI; 1.29-7.27, P = 0.011). Mortality rates were not higher in those who restarted warfarin in-hospital: 31.9% vs 54.4% (30-day, P < 0.001) and 48% vs 61% (1-year, P = 0.04), and bleeding was not increased. Multivariable predictors of mortality included initial international normalized ratio > 3.0 (aOR, 3.28 [30-day, P < 0.001] and 3.32 [1-year, P = 0.003]), greater stroke severity (aOR, 6.04 [30-day] and 4.22 [1-year]; both P < 0.001), and intraventricular hemorrhage (aOR, 2.19 [30-day; P = 0.03] and 2.04 [1-year; P = 0.04]). In selected patients who reinitiated warfarin, there was no increase in 30-day (aOR, 0.49; P = 0.03) or 1-year mortality (aOR, 0.79; P = 0.43).
Conclusions — In selected patients at high thrombosis risk, reinitiation of warfarin after ICH did not confer increased mortality or bleeding events.