Successful revascularization -- defined as modified Thrombolysis in Cerebral Infarction (mTICI) scores 2b or 3 at the end of all endovascular treatments -- reached 85.4% with contact aspiration versus 83.1% with stent retriever use (OR 1.20, 95% CI 0.68-2.10), reported Bertrand Lapergue, MD, PhD, of Foch Hospital in Suresnes, France, and colleagues.
Outcomes were similar between groups, too, for National Institutes of Health Stroke Scale (NIHSS) score improvement at 24 hours (-4.8 versus -5.2 points, P=0.68) and functional independence at 90 days (45.3% versus 50.0%, OR 0.83, 95% CI 0.54-1.26).
ASTER's first-line results were previously reported at this year's International Stroke Conference and are now published online in the Journal of the American Medical Association.
"First-line contact aspiration was not superior to first-line stent retriever in achieving successful revascularization at the end of the endovascular procedure," Lapergue's group concluded.
However, the authors maintained that this was a superiority trial designed to demonstrate a 15% absolute increase in successful revascularization by thrombus aspiration. "A smaller yet potentially clinically significant difference in revascularization rate cannot be fully excluded," they said.
"Theoretically, contact aspiration could result in a higher rate of an mTICI score of 3 compared with stent retriever because use of a stent retriever requires that it be passed through the clot and therefore might result in a higher rate of distal emboli (as was found in an in vitro study), but there were no significant differences between groups in the secondary outcome of an mTICI score of 3 or in the frequency of embolization to a new vascular territory in this study."
The trial randomized eligible patients with acute ischemic stroke in the anterior circulation to treatment with contact aspiration (n=192) or stent retriever therapy (n=189) before urgent mechanical thrombectomy at eight comprehensive stroke centers in 2015-2016. Those who were eligible also received IV thrombolysis prior to arrival at the angiographic suite.
The study group had a mean age of 69.9 years and 45.7% were women. Average baseline NIHSS score was 16.2 and a median 227 minutes elapsed from symptom onset to arterial puncture.
Baseline differences emerged in age, admission systolic blood pressure, prestroke mRS score, and site of occlusion.
Rescue treatment resulting in switching or combining therapies was required in 32.8% of the contact aspiration versus 23.8% of stent retriever groups (OR 1.57, 95% CI 0.99-2.47). There were numerically more symptomatic intracranial hemorrhages at 24 hours with stent retriever use (6.5% versus 5.3%), as well as new ischemic strokes in different vascular territories (8.5% versus 5.3%).
Lapergue had no disclosures listed.
Co-authors reported several relationships with industry.
Journal of the American Medical AssociationSource Reference: Lapergue B, et al "Effect of endovascular contact aspiration vs stent retriever on revascularization in patients with acute ischemic stroke and large vessel occlusion: the ASTER randomized clinical trial" JAMA 2017; DOI: 10.1001/jama.2017.9644.