Background
Medium vessel occlusions (MeVO) of intracranial arteries constitute 25% of all acute ischemic strokes. More than 50% of MeVO stroke patients with untreated arterial occlusion develop significant functional impairment. However, there is a significant paucity in high quality endovascular thrombectomy data for MeVO involving segments of the middle cerebral artery such as M2 or M3. On this basis, there is equipoise in treatment choices for MeVO and this is reflected in unclear recommendations in international treatment guidelines.
Aims
To determine if the clinical outcomes of ischaemic stroke patients with MeVO treated within 9-hour by endovascular thrombectomy will be superior to standard therapy (thrombolytics by intravenous alteplase or tenecteplase within the clinically indicated timeframes).
Methods
FRONTIER-AP is an Australian-led international clinical trial (Australia, New Zealand, China and Vietnam) with prospective, randomized, open blinded end-point design. We include acute ischemic stroke patients within 9 hours of symptom onset and with MeVO (middle cerebral artery M2, M3, or anterior cerebral artery A1 or A2 segments) identified by vascular imaging. We randomize patients (1:1) to either endovascular thrombectomy or standard medical therapy. The primary outcome is Modified Rankin Score at 3 months at follow up.
Conclusion
FRONTIER-AP will: i) finally address a longstanding evidence gap impacting patient outcomes ii) support much-needed change in practice and policy to improve patient access to early thrombectomy for MeVO stroke, both here and internationally iii) reduce the risk of lifetime disability and functional deficits for this overlooked patient cohort.