on behalf of the MR CLEAN-MED investigators
Many ischemic stroke patients do not recover despite fast and complete reperfusion after endovascular therapy (EVT). It is unknown whether periprocedural antithrombotic therapy improves clinical outcome. Our objective was to assess the effect of periprocedural acetylsalicylic acid (ASA), unfractionated heparin (UFH), both, or neither.
MR CLEAN-MED was a multicenter, prospective, randomized, open-label, blinded-endpoint trial with a 2x3 factorial design. Eligible patients had a clinical diagnosis of ischemic stroke and confirmed intracranial anterior circulation occlusion that could be treated intra-arterially within 6 hours of symptom onset. Patients were randomized for periprocedural intravenous treatment with ASA (300mg bolus) or no ASA, and for moderate-dose UFH (5000 IU bolus, and 1250 IU/hour for 6 hours), low-dose UFH (5000 IU bolus, and 500 IU/hour for 6 hours) or no UFH. The primary outcome was the modified Rankin Scale (mRS) score at 90 days. Safety endpoints included symptomatic intracranial hemorrhage (sICH) and death. We planned to enroll 1500 patients.
After enrolling 132 patients, the Steering Committee decided to stop assigning moderate-dose UFH, because of an increased risk of sICH (adjusted OR 10.0, 95%CI 2.6-40.0). Enrolment in the other arms continued. After enrolling 629 patients, the Steering Committee decided to stop enrollment in the remaining arms, for reasons of safety rather than efficacy. Decisions were taken after obtaining advice from the Data Safety and Monitoring Board, which was based on the 2nd interim analysis and 11th safety analysis.
Follow-up will be completed by May 2021. Final results of the trial will be presented at the meeting.
ISRCTN76741621