A substudy of the DISTAL randomised clinical trial: Endovascular treatment for stroke patient with medial and distal vessel occlusions ineligible for IVT and with severe neurological deficits

The DISTAL trial evaluated the effectiveness of best medical treatment (BMT) plus endovascular therapy (EVT) compared to BMT alone on functional outcome 90 days post ischemic stroke in patients with medial and distal vessel occlusions. This study was an international, multicentre, randomized, controlled trial. For patients with stroke caused by medium or distal vessel occlusions, intravenous thrombolysis (IVT) remains the only approved treatment, with recent randomized data failing to demonstrate a benefit in this broad and heterogeneous population. However, a significant subset of patients is ineligible for IVT due to late presentation or other contraindications, and these patients are at increased risk of poor outcome. Given the proven efficacy of EVT in late-window in patients with large vessel occlusions, it is possible that EVT for medium or distal vessel occlusions may be superior to best medical treatment alone in patients who cannot receive IVT. This may be particularly true for those with more severe deficits, where the benefits of reperfusion more likely outweigh the procedural risks. A subgroup analysis assessing the treatment effect in patients who did not receive IVT was part of the main analysis of the trial, and did not show difference in outcome at 90 days. The analysis at hand is a subanalysis of the trial, in which the aim is to investigate Is EVT plus BMT superior to BMT alone in patients who are not eligible for IVT and who present with severe neurological deficits, as defined by an NIHSS of 6 or higher. Given the general treatment policy in the participating countries, we assume that all patients eligible for IVT also received IVT. This analysis aims to investigate the question whether the effect of EVT plus BMT versus BMT alone on clinical outcome in patients who are not eligible for IVT and who present with severe neurological deficits. We hypothesize that in patients with severe NIHSS a benefit of EVT will be higher in patients not receiving IVT.