A multicenter, prospective, observational study of warfarin-associated intracerebral hemorrhage: The SAMURAI-WAICH study

Background Because patients with warfarin-associated intracerebral hemorrhage (WAICH) have a high risk of ongoing bleeding, disability, and death, urgent coagulopathy reversal should be considered. On the other hand, thromboembolism may occur with reversal or withholding of anticoagulant therapy. The current status of acute hemostatic treatments and clinical outcomes in WAICH patients was investigated. Methods WAICH patients admitted within 3 days of onset were prospectively enrolled in 10 stroke centers. Thromboembolic and hemorrhagic complications and functional outcomes were followed-up for one year. Results Of 50 WAICH patients (31 men, 73 ± 9 years old) enrolled, all stopped warfarin on admission. Elevated prothrombin time-international normalized ratios (PT-INR) were normalized in 43 (86%). Anticoagulant therapy was resumed with intravenous full-dose unfractionated heparin followed by warfarin in 9 (18%), intravenous low-dose unfractionated heparin followed by warfarin in 14 (28%) and warfarin alone in 14 (28%) at a median of 2.5 (IQR 1.25-9), 4 (2-5.5) and 6 (3-11) days after onset, respectively, after emergent admission. Onset-to-admission time (per 1-hour increase; OR 0.55, 95% CI 0.19-0.84) was inversely associated with hematoma expansion. Anticoagulant therapy was resumed with intravenous full-dose unfractionated heparin in 9 (18%), low-dose heparin in 14 (28%) and warfarin alone in 14 (28%) at a median of 2.5, 4 and 6 days after onset, respectively. During one-year follow-up (n = 47), 11 thromboembolic and 6 hemorrhagic complications were documented. Twenty four patients showed unfavorable outcomes, corresponding to a modified Rankin Scale score of 4-6. Thromboembolic complications (OR, 10.62; 95% CI, 1.05-227.85), as well as advanced age (per 1 year; OR, 1.27; 95% CI, 1.10-1.61) and higher National Institutes of Health Stroke Scale (NIHSS) score (per 1 point; OR, 1.24; 95% CI 1.07-1.55), were independently associated with unfavorable outcome. Conclusions PT-INR normalization on admission and early anticoagulant resumption were common in WAICH patients. Thromboembolic complications were independently associated with unfavorable outcome.