For people who experience a first non-cardioembolic ischemic stroke (NCIS) or transient ischemic attack (TIA), the danger doesn’t end at hospital discharge. New research presented at the 2025 World Stroke Congress shows that the risk of recurrent events and death remains substantial, especially in the first 90 days after leaving the hospital.
The analysis, conducted by researchers from leading US academic institutions in collaboration with Truveta and Bayer, used real-world electronic health record (EHR) data from Truveta Data to examine outcomes after NCIS and TIA at a scale rarely possible in stroke research. The findings underscore an urgent opportunity to strengthen secondary prevention during a narrow but critical window of risk.
Studying stroke outcomes at national scale
Most prior studies of stroke recurrence have focused on cardioembolic stroke or narrowly defined patient populations. As a result, there has been limited visibility into what happens to patients with non-cardioembolic ischemic stroke and TIA in routine clinical practice across the United States.
To address this gap, investigators conducted a retrospective observational study using Truveta Data, which provides access to daily-updated EHR data from a collective of 30 US health systems. The dataset spans care delivered across more than 900 hospitals and 20,000 clinics, enabling a nationally representative view of patient outcomes.
The study included 234,413 adults with a first diagnosis of NCIS or TIA between 2017 and 2023, with outcomes tracked for up to one year after hospital discharge. By following patients longitudinally across care settings, the researchers were able to quantify real-world risks of recurrent stroke, recurrent TIA, and all-cause mortality.
What the data show: Risk remains high after discharge
Across the cohort, the analysis revealed clear and clinically meaningful differences between patients with NCIS and those with TIA, with the common theme that the first 90 days after discharge matter most.
Recurrent ischemic stroke after NCIS
Patients with NCIS faced a substantial risk of another ischemic stroke within the first year. Approximately 1 in 10 patients (10.3%) experienced a recurrent ischemic stroke within 12 months of discharge. The risk peaked within the first 30–90 days, then began to level off, highlighting a concentrated period of vulnerability soon after hospitalization.
Repeat TIA after TIA
Patients whose index event was a TIA showed a different pattern. While they were less likely to experience a subsequent ischemic stroke than patients with NCIS, they were more likely to have another TIA. About 1 in 30 patients with TIA (3.5%) experienced a recurrent TIA within one year.
Mortality risk within the first year
All-cause mortality was consistently higher after NCIS than after TIA. Nearly 1 in 9 patients with NCIS (10.8%) died within one year of discharge, compared with 1 in 23 patients with TIA (4.4%). As with recurrent events, most deaths among patients with NCIS occurred within the first 90 days post-discharge.
Why timing matters for secondary prevention
Together, these findings indicate that the period immediately following discharge represents a critical window for intervention. Despite advances in acute stroke care, patients with NCIS and TIA remain at meaningful risk for recurrent events and death once they return to the community.
By capturing longitudinal patient journeys across health systems, this study illustrates how real-world data can surface risk patterns that are difficult to observe in trials or registries alone. Understanding when adverse outcomes are most likely to occur is essential for designing more effective secondary prevention strategies, and for ensuring patients receive the right follow-up care at the right time.
As stroke remains a leading cause of death and disability worldwide, real-world evidence like this can help clinicians, researchers, and health systems better understand where risk persists and where prevention efforts can have the greatest impact.