Minor Stroke Therapy Evaluation

Overview

Stroke represents the fourth leading cause of death in industrialized nations, after heart disease, cancer, and chronic lower respiratory disease. Approximately one-quarter of the patients suffering a stroke die within one year after the initial event and stroke is a leading cause of serious long-term disability. Although mechanical thrombectomy (MT) has become the standard of care for acute ischemic stroke with proximal large vessel occlusion (LVO) in the anterior circulation, the management of patients harboring proximal occlusion but presenting minor-to-mild stroke symptoms, has not yet been determined by these recent randomized clinical trials. However, patients with proximal occlusions may present with a low NIHSS, a proximal intraarterial occlusion being present in up to 28% when considering patients with an NIHSS ≤ 4. The evidence of benefit from endovascular therapy (EVT) in large vessel occlusion stroke is demonstrated, STAIR IX (Stroke Treatment Academic Industry Roundtable) consensus recommendations were developed that outline priorities for future research in EVT.

Proximal intracranial arterial occlusions cause the most disabling types of ischemic strokes and are predictive of poor neurological outcomes. The "Time is Brain" assessment has been confirmed in many recent trials (MR CLEAN, SWIFT PRIME, REVASCAT, HERMES) within the first 6 hours. Recently the time window has been enlarged to 24h00 after the DAWN trial results, enforcing nevertheless the strong relation between patient disability and time loss in this extended time window. In population-based studies, patients presenting with minor or mild stroke symptoms represent about two-thirds of stroke patients, and almost one-third of these patients are unable to ambulate independently at the time of discharge. Although mechanical thrombectomy (MT) has become the standard of care for acute ischemic stroke with proximal large vessel occlusion (LVO) in the anterior circulation, the management of patients harboring proximal occlusion but presenting minor-to-mild stroke symptoms, has not yet been determined by these recent randomized clinical trials. Indeed, the majority of patients presented with major clinical impairment, with a median NIHSS of 17. Thus, American Heart Association (AHA) gives level 1a evidence for MT performed only for patients with baseline NIHSS score ≥6. However, patients with proximal occlusions may present with a low NIHSS, a proximal intra-arterial occlusion being present in up to 28% when considering patients with an NIHSS ≤ 4. In observational study, patient with minor or mild stroke symptoms and LVO have a high risk of both clinical worsening and bad outcome. The STAIR meeting aims to advance acute stroke therapy development through collaboration between academia, industry, and regulatory institutions. In pursuit of this goal and building on the available level I evidence of benefit from endovascular therapy (EVT) in large vessel occlusion stroke, STAIR IX consensus recommendations were developed that outline priorities for future research in EVT. Recent AHA/ASA guidelines have also highlighted the need to gain more evidence to determine whether there is an overall net benefit from endovascular therapy (EVT) in patients with LVO and minor stroke. The MOSTE protocol is an International, multi-center, prospectively randomized to two parallel (1:1) arms, open to treatment with blinded endpoint trial, designed to demonstrate that mechanical thrombectomy with best medical treatment is superior to medical treatment alone, in improving clinical outcomes at 90 days, in patient presenting an acute large vessel occlusion stroke with a minor deficit, defined as NIHSS below 6 and \< 24 hours from onset. If this study is positive, more patients in the future could receive urgent endovascular treatment in addition to the best medical treatment.