Real-world stent retriever thrombectomy for acute ischemic stroke beyond 6 hours of onset: analysis of the NASA and TRACK registries

Background The DEFUSE 3 and DAWN trials have shown the benefit of thrombectomy beyond 6 hours of stroke symptom onset in carefully selected patients. Objective To evaluate the real-world outcomes of stent retriever thrombectomy beyond 6 hours of stroke onset using combined individual patient data from the North American Solitaire Stent Retriever Acute Stroke (NASA) and Trevo Stent-Retriever Acute Stroke (TRACK) registries. Methods Pooled analysis of individual patient data of all cases of anterior circulation acute ischemic stroke (AIS) from NASA and TRACK was performed to compare outcomes of patients presenting within the first hours 6 or beyond 6 hours of stroke symptom onset. Results Of 830 patients with anterior circulation AIS from the NASA and TRACK registries, 32.7% (271 patients) underwent thrombectomy beyond the first 6 hours of symptom onset. The rates of good clinical outcome (modified Rankin scale score of 0–2 at 90 days), mortality, and symptomatic intracranial hemorrhage were similar: 48.1%, 20.6%, and 8.0% within 0–6 hours, 46.2%, 21.6%, and 10.9% within 6–16 hours, and 38.9%, 33.3%, and 5% within 16–24 hours (p=0.8, 0.6, and 0.5, respectively). The rates of successful recanalization (Thrombolysis in Cerebral Infarction 2b/3) were 79.4% in patients with stroke within 0–6 hours, 72.6% within 6–16 hours, and 85.0% within 16–24 hours (p=0.04). Conclusions Real-world experience with patients with anterior circulation AIS treated with the Solitaire and Trevo thrombectomy devices beyond the first 6 hours of symptom onset proved to be equally safe and effective as for patients with symptom onset within the first 6 hours.