"We were surprised by the results, as our hypothesis - based on previous observational studies - was that treatment with periprocedural antithrombotics would be beneficial," Dr. Wouter van der Steen of Erasmus University Medical Center in Rotterdam told Reuters Health by email. "We can now recommend avoiding the evaluated dosages of aspirin and heparin during endovascular stroke treatment. We consider it wise to implement this in the guidelines."
Before the trial started, he noted, observational studies suggested periprocedural antithrombotics were beneficial despite a moderately increased risk of stroke. No guideline recommendations were made, so there has been large practice variation, which was part of the rationale for the current study.
As reported in The Lancet, Dr. van der Steen and colleagues randomly assigned 628 patients (median age, 73; about 52% male) with ischemic stroke due to an intracranial large-vessel occlusion to receive either periprocedural IV aspirin (300 mg bolus) or no aspirin, or moderate-dose unfractionated heparin (5,000 IU bolus followed by 1,250 IU/h for 6 h), low-dose unfractionated heparin (5,000 IU bolus followed by 500 IU/h for 6 h), or no unfractionated heparin.
The primary outcome was the score on the modified Rankin Scale at 90 days.
Patients were enrolled between January 2018-January 2021. On February 4, 2021, after unblinding and analysis of the data, the trial steering committee permanently stopped patient recruitment and the trial was stopped due to safety concerns.
The risk of symptomatic intracranial hemorrhage was higher in patients receiving aspirin than in those not receiving aspirin (14% vs. 7%; adjusted odds ratio, 1.95), and in those receiving unfractionated heparin than in those not receiving it (13% vs. 7%; aOR, 1.98).
Both aspirin (adjusted common OR, 0.91) and unfractionated heparin (0.81) led to a non-significant shift towards worse modified Rankin Scale scores.
The authors concluded, "Periprocedural intravenous aspirin and unfractionated heparin during endovascular stroke treatment are both associated with an increased risk of symptomatic intracranial hemorrhage without evidence for a beneficial effect on functional outcome."
Dr. Mohammed Almekhlafi of the Cumming School of Medicine, University of Calgary, coauthor of a related editorial, commented in an email to Reuters Health. "Stroke guidelines do not endorse the use of heparin or aspirin concurrently with intravenous thrombolysis or endovascular thrombectomy. This study (MR CLEAN-MED)'s findings support this practice."
"While these results do not change current practice," he said, "we are left with a few outstanding questions. The problem that motivated the trial design remains unaddressed: around half of stroke patients with large vessel occlusions do not achieve good outcomes despite timely treatment with IV thrombolysis or endovascular thrombectomy."
"The premise of MR CLEAN-MED was to prevent or treat thrombi at the microcirculation level," he said. "However, these microthrombi might not play as a big rule as anticipated. Alternatively, the antithrombotic agents used or their timing in relation to stroke onset might have negatively impacted the results."
"An ongoing trial (MOST) is looking at the benefit of different antithrombotic agents among stroke patients receiving IV thrombolysis with or without thrombectomy within three hours from onset," he noted. "The administration of these agents locally into the brain circulation could be an alternative."
The study was funded in part by Stryker, Medtronic, and Cerenovus.
SOURCE: https://bit.ly/3CV4RKX The Lancet, online February 28, 2022.
By Marilynn Larkin
Posted on
site created by:
© 2024 Medicom Medical Publishers. All rights reserved. Terms and Conditions | Privacy Policy