Abstract DP297: Characteristics and Outcomes of the Real-World Cohort of Patients with Non-Cardioembolic Ischemic Stroke or Transient Ischemic Attack Compatible With the OCEANIC-STROKE Clinical Trial Population in Japan

Introduction: The Phase III OCEANIC-STROKE trial (NCT05686070) investigates whether the activated Factor XI inhibitor asundexian combined with antiplatelet therapy (APT) reduces the risk of recurrent IS in patients with non-cardioembolic IS (NCIS) or high-risk TIA compared with APT alone. The objective of the present investigation was to describe the characteristics and outcomes of patients compatible with the OCEANIC-STROKE trial population among patients hospitalized for a first-ever NCIS or TIA in real-world settings in Japan. Methods: ASTRIS Japan was a retrospective cohort study using a Japanese nationwide hospital database (RWD Co.). Adults with a first hospitalization for NCIS or TIA between Jan 1, 2015 and Oct 29, 2022 were identified. Among them, a subset of patients compatible with the OCEANIC-STROKE trial population was selected by applying the emulated eligibility criteria of the OCEANIC-STROKE trial. Clinical events were assessed after discharge of the index NCIS or TIA hospitalization. Events that occurred during the hospitalization for index stroke were not considered. Results: In total, 18,719 patients with NCIS or TIA were identified. Of these, 5778 patients were identified for the OCEANIC-STROKE-compatible cohort (Fig 1). The median (Q1, Q3) length of follow-up was 715 (170.8, 1355.3) days. Table 1 shows the baseline characteristics of the OCEANIC-STROKE-compatible cohort. Mean±SD age was 73.1±11.9 years and 37.7% were female. Most (70.4%) patients initiated APT within 2 days of hospital admission. Single APT was used in 4830 (83.6%) patients and dual APT was used in 1991 (34.5%) patients, and were not mutually exclusive. Rates (per 1000 patient-years [95% CI]) of IS, hemorrhagic stroke, and major bleeding were 106.1 (100.0–112.1), 8.9 (7.3–10.5), and 47.2 (43.4–51.0), respectively. Compared with the overall NCIS or TIA cohort, a numerically higher rate of IS and a numerically lower rate of major bleeding were observed in the OCEANIC-STROKE-compatible cohort up to 5 years (Fig 2). Baseline characteristics of the overall NCIS or TIA and the OCEANIC-STROKE-compatible cohorts will be compared with those of patients in the OCEANIC-STROKE trial. Conclusions: In real-world settings, patients compatible with the enrolled OCEANIC-STROKE trial population had a high risk of IS recurrence following hospital discharge in Japan. Further improvements in secondary stroke prevention strategies are merited.