Stroke severity and outcomes in patients with intracerebral hemorrhage on anticoagulants and antiplatelet agents: an analysis from the Japan Stroke Data Bank

Background and aim: Some patients with intracerebral hemorrhage are on antithrombotic agents at the time of the event and these may worsen outcome, but the relative risk of different oral anticoagulants and antiplatelet agents is uncertain. We determined associations between pre-onset intake of antithrombotic agents and initial stroke severity, and outcomes, in patients with intracerebral hemorrhage. Methods: Patients with intracerebral hemorrhage admitted within 24 h after onset between January 2017 and December 2020 and recruited to the Japan Stroke Data Bank, a hospital-based multicenter prospective registry, were included. Enrolled patients were classified into four groups based on the type of antithrombotic agents being used on admission. The outcomes were the National Institutes of Health Stroke Scale (NIHSS) score on admission and modified Rankin Scale (mRS) of 5–6 at discharge. Results: Of a total 9810 patients with intracerebral hemorrhage (4267 females; mean age = 70 ± 15 years), 77.1% were classified into the no-antithrombotic group, 13.2% into the antiplatelet group, 4.0% into the warfarin group, and 5.8% into the direct oral anticoagulant (DOAC) group. Median (interquartile range) NIHSS score on admission was 12 (5–22), 13 (5–26), 15 (5–30), and 13 (6–24), respectively, in the four groups. In multivariable analysis, the prestroke warfarin use was associated with higher NIHSS score (adjusted incidence rate ratio = 1.09 (95% confidence interval (CI) = 1.06–1.13), with the no-antithrombotic group as the reference), but the antiplatelet group (1.00 (95% CI = 0.98–1.02)) and DOAC group (0.98 (95% CI = 0.95–1.01)) were not. The rate of mRS 5–6 at discharge was 30.8%, 41.9%, 48.6%, and 41.5%, respectively, in the four groups. In multivariable analysis, prestroke warfarin use was associated with mRS 5–6 (adjusted odds ratio = 1.90 (95% CI = 1.28–2.81), with the no-antithrombotic group as the reference), but the antiplatelet group (1.12 (95% CI = 0.91–1.37)) and DOAC group (1.25 (95% CI = 0.88–1.77)) were not. Conclusion: Patients who were taking warfarin prior to intracerebral hemorrhage onset suffered more severe intracerebral hemorrhage as evidenced by higher admission NIHSS and higher discharge mRS. In contrast, no increase in severity was seen with antiplatelet agents.