Abstract Body: Background: The therapeutic time window of endovascular therapy (EVT) for acute ischemic stroke (AIS) has been expanded up to 24 hours of onset. Patients with AIS beyond 24 hours may also benefit from EVT, but the actual status of this clinical issue is unknown.
Purpose: To evaluate the real-world status of EVT for AIS beyond 24 hours of onset using a nation-wide stroke registry, Japan Stroke Data Bank (JSDB). JSDB is an ongoing hospital-based multicenter prospective registry of hospitalized patients with acute stroke or transient ischemic attack within 7 days of onset.
Methods: From the JSDB dataset, patients with AIS who underwent EVT from 1996 through 2021 were analyzed. Patients were divided into 3 groups according to time from onset to hospital arrival (early: <4.5 hour; late: 4.5–24 hour; and very late: >24 hour). Outcomes included the favorable outcome (mRS 0–2 or return to pre-stroke mRS at discharge) and in-hospital mortality.
Results: Among the 256,293 stroke patients, 91,907 AIS patients available for analysis were included in the present study. EVT was implemented in 6.9% (6,356/91,907) (median age 78 years; 41.6% women; median NIHSS score 16). The EVT rate by time window groups was 11.8% (4,258/36,044) for the early, 5.3% (1,676/31,328) for the late, and 1.7% (422/24,535) for the very late group. In the very late group with EVT, baseline NIHSS score was lowest (median 17 points in the early group, 14 points in the late group, and 5 points in the very late group), cardioembolism was least common (67.2%, 53.5%, and 22.0%, respectively), and large artery atherosclerosis was most common (17.9%, 30.8%, and 55.7%, respectively). Favorable outcome was more frequently achieved in the very late group (52.9%) than in the early (41.6%) and late (36.5%) groups. Symptomatic intracranial hemorrhage was more frequently seen in the very late group (6.0%) compared to the early (2.9%) and late (3.8%) groups, but in-hospital mortality was comparable among the time window groups (8.1% in the early group, 7.1% in the late group, and 6.6% in the very late group).
Conclusions: Outcomes after EVT for patients with AIS beyond 24 hours were not necessarily worse than for patients with AIS up to 24 hours, but the patient profile in the very late group with EVT differed significantly from that in the early and late groups; developing optimal patient selection strategies for very late AIS may be required.