For patients with acute ischemic stroke and large-vessel occlusion in the anterior circulation, a new contact-aspiration system and a standard stent-retriever approach for first-line mechanical thrombectomy have similar efficacy and safety, according to results of the French ASTER trial, published in JAMA online August 1.

“This is the first large, independent randomized-controlled trial focusing on ADAPT (Interest of Direct Aspiration First Pass Technique), a new strategy for removing the clot in acute stroke by an aspiration catheter,” lead author Dr. Bertrand Lapergue, from Foch Hospital, University Versailles Saint-Quentin en Yvelines, Suresnes, France, told Reuters Health by email.

“The ASTER trial shows no statistical difference between aspiration and stent retriever as a front-line thrombectomy approach with similar efficacy and safety endpoints,” Dr. Lapergue said.

The ASTER trial, conducted in eight comprehensive stroke centers in France, was a prospective, open-label study comparing mechanical thrombectomy using the contact-aspiration technique with the standard stent-retriever technique for first-line endovascular revascularization. In all, 381 patients (mean age, 70; 46 percent women) with acute ischemic stroke and large-vessel occlusion were randomized.

The study was partly funded by Penumbra (Alameda, California), maker of the contact-aspiration system.

Successful revascularization, defined as a modified thrombolysis in cerebral infarction score of 2b or 3, was achieved in 85 percent of patients in the contact-aspiration group and 83 percent of patients in the stent-retriever group, a statistically nonsignificant difference.

No marked between-groups differences were found in the clinical efficacy outcomes of change in the National Institutes of Health Stroke Scale (NIHSS) score at 24 hours, change in the modified Rankin Scale (mRS) score at 90 days, or procedure-related adverse events.

The authors note in their report that the trial had “very few restrictive inclusion criteria in keeping with clinical situations.” They conclude that first-line contact aspiration was not superior to first-line stent retriever in achieving successful revascularization at the end of the endovascular procedure.

“The hypothesis of this trial,” they point out, “was that use of first-line contact aspiration would increase the rate of successful revascularization by 15 percent compared with a first-line stent retriever (superiority design).” Therefore, they note, the study “was not designed to claim equivalence or non-inferiority of these strategies” and that “although the contact aspiration group did not achieve a 15 percent increase in successful revascularization, a smaller yet potentially clinically significant difference in revascularization rate cannot be fully excluded.”

In an email to Reuters Health, Dr. Lapergue added, “The standard procedure of mechanical thrombectomy in stroke is the stent retriever, which has been proved across six large randomized-controlled trials. For the first time, a large trial compared contact aspiration and stent retriever. Contact aspiration appears as an alternative strategy for removing the clot.” Dr. Lapergue noted that further research will need to identify the best technique to use, given the patient’s characteristics and the clot location, for improving clinical outcomes. He also highlighted the need to assess the value of combining the two strategies (contact aspiration plus stent retriever), a matter that the forthcoming ASTER2 trial will address.