Endovascular Therapy for Mild and Late-Presenting Acute Ischemic Stroke: Benefits and Safety

Two randomized trials conducted in China found that endovascular therapy improved functional outcomes in patients with acute ischemic stroke caused by anterior-circulation large-vessel occlusion and imaging evidence of salvageable brain tissue, both within 24 hours and 24–72 hours after symptom onset, although the benefits were accompanied by important safety concerns. In the first multicenter, open-label, randomized trial, patients with mild stroke, defined as a National Institutes of Health Stroke Scale (NIHSS) score below 6, a small infarct core, and a large perfusion-mismatch volume indicating substantial at-risk brain tissue were treated within 24 hours of symptom onset or the time they were last known to be well. Among 300 patients in the modified intention-to-treat analysis, 144 received endovascular therapy plus medical management and 156 received medical management alone. At 90 days, an excellent functional outcome, defined as a modified Rankin Scale (mRS) score of 0–1, indicating no symptoms or no clinically significant disability, was achieved by 69.4% of patients in the endovascular-therapy group, compared with 50.0% in the medical-management group (odds ratio, 2.32). Symptomatic intracranial hemorrhage within 48 hours occurred in three patients in each group. However, serious procedure-related complications occurred in 19 patients (13.2%) receiving endovascular therapy, and one death occurred in this group. The second open-label, randomized trial, which used blinded outcome assessment at comprehensive stroke centers, investigated patients with anterior-circulation large-vessel occlusion and imaging-confirmed salvageable brain tissue who were treated 24–72 hours after symptom onset or the time they were last known to be well. A total of 336 patients were included in the intention-to-treat analysis, with 168 each assigned to endovascular therapy plus standard medical care and to standard medical care alone, respectively. The median time from symptom onset or last-known-well time to randomization was 38.5 hours. At 90 days, endovascular therapy resulted in a more favorable overall distribution of mRS scores than standard medical care alone (common odds ratio for a better functional outcome, 1.74). Nevertheless, symptomatic intracranial hemorrhage occurred in 4.8% of patients receiving endovascular therapy, compared with none in the control group, and 90-day mortality was 6.0% versus 1.8%, respectively. These findings suggest that selected patients with large-vessel occlusion and salvageable brain tissue may benefit from endovascular therapy even when neurological deficits are mild or treatment is initiated 24–72 hours after symptom onset. However, careful imaging-based patient selection and individualized assessment of potential functional benefits versus procedural complications, intracranial hemorrhage, and mortality risks remain essential. Source: https://www.nejm.org/