The European Stroke Organisation conference (ESOC) took place in Glasgow on April 17-19 2015. As a partner society, ESMINT was involved in several well-attended workshops and joint sessions with ESO. Additionally there was a guideline meeting for the ESO/ESMINT/ESNR/EAN/EANS/EuSEM (“6E”) guidelines for organisation of acute endovascular treatment in stroke centers.
More important, another three new thrombectomy studies have been presented at ESOC for the first time. SWIFT-PRIME and REVASCAT have been published in parallel simultaneously in the NEJM.
REVASCAT is a randomized trial of revascularization with Solitaire FR device vs. best medical therapy in patients with anterior circulation large vessel occlusion within eight hours of symptom onset in Catalonia. Patients with acute ischemic stroke ineligible for IV tPA treatment and non-responders to IV tPA were included. Thrombectomy reduced the severity of disability over the range of the modified Rankin scale (adjusted odds ratio for improvement of 1 point, 1.7; 95%CI, 1.05 to 2.8) and led to higher rates of functional independence (a score of 0 to 2) at 90 days (43.7% vs. 28.2%; adjusted odds ratio, 2.1; 95%CI, 1.1 to 4.0, ARR 15.5%). Another outstanding feature of this study is that only eight patients who met the eligibility criteria were treated outside the trial at participating hospitals.
THERAPY is a randomized trial that compared the Penumbra system in various development stages in combination with different types of separators with best medical therapy (Separator and Separator 3D used in 82%, Ace in 27%). The study has been stopped due to lack of equipoise after enrolling 108 patients with 96 follow-up data sets available. Key inclusion criteria were IV tPA within 4.5 h and clot length larger than 8 mm as measured by CT. The study revealed no superiority of the mixed endovascular arm for the primary endpoint in the intention-to-treat analysis. The mRS 0-2 (day 90) was 30.4% in the medical therapy group and 38.0% in the endovascular arm (ARR 7.6%, p=0.521). However, pre specified per-protocol analysis of ordinal mRS showed superiority of the endovascular treatment (OR 2.28 95%CI (1.05 to 4.96)). As THERAPY used unique selection criteria, impact is difficult to assess across this small population.
The French THRACE study is a randomized trial of endovascular revascularization in stroke with any device approved in France vs. best medical therapy in patients with large vessel occlusion within six hours. The patient recruitment is stopped. Currently, the 90-days data of the very recently enrolled patients are still incomplete. However, the preliminary results were reported. In this preliminary analysis based on 385 enrolled patients with available outcome data, the mRS 0-2 (day 90) was 42.1% in the medical therapy group and 54.2% in the endovascular group (ARR 12.2%, p=0.016). Occlusions were M1 in 85%, ICA in 14.5% and BA in 0.5%. This no company-sponsored public trial is very important as it shows the benefit of endovascular revascularization on a countrywide scale even when wide inclusion criteria are applied.
Additionally, more subgroup analyses of SWIFT-PRIME, ESCAPE, EXTEND-IA and MR Clean have been presented. In a positive atmosphere, future steps in the development of thrombectomy have been discussed concerning optimization of workflow, definition of patient selection criteria, training of future Neuroradiologists and refinements of techniques.