Could collateral assessment replace CT perfusion?
Commenting on the MR CLEAN-LATE trial, Stefan Kiechl, MD, Medical University of Innsbruck (Austria), who is cochair of the WSC scientific committee, said it was an “excellent study.”
“This study does not rely on advanced imaging (e.g., mismatch) and criteria can easily be interpreted on CT/CTA. If the study is published and all details are available this study may substantially ease endovascular therapy in the late time window,” Dr. Kiechl told this news organization.
Also commenting, Urs Fischer, MD, chairman of the department of neurology at the University Hospital Basel (Switzerland), who was not involved with MR CLEAN-LATE, said: “This is another study that has nicely shown that endovascular therapy in patients in the later time window is highly effective.”
Dr. Fischer said he was not surprised by the results.
“I was expecting the trial to be positive,” he said. “What we can say is that endovascular therapy in patients with proximal vessel occlusion is a very effective intervention – probably one of the most important interventions in the history of medicine – and now we have another subgroup to whom we can offer this therapy. So, this is an important study that will improve the outcome of many further patients.”
Yvo Roos, MD, professor of acute neurology at University Medical Center, Amsterdam, who was a MR CLEAN-LATE investigator, agreed that the trial has the potential to increase number of patients who can be treated with endovascular therapy.
But both Dr. Roos and Dr. Fischer were not convinced that collateral assessment would replace CT perfusion as the first-line choice in selecting patients for endovascular treatment.
“We need to see what kind of patients were included in the trial and what kind of perfusion imaging characteristics they had, to see how they compare with patients selected by perfusion imaging,” Dr. Roos noted. “I think CT perfusion is here. But if the data shows that collateral score is better able to identify patients for endovascular treatment than CT perfusion, then this has the potential to change practice. But that needs to be shown.”
All patients screened for the MR CLEAN-LATE trial also received CT perfusion imaging as part of the standard imaging protocol, and many were selected for endovascular therapy directly on this basis, so would not have entered the trial. The researchers plan to analyze these results and to compare how the two approaches differ.
MR CLEAN-LATE is an investigator-driven study, funded by the Dutch Heart Foundation, the Brain Foundation Netherlands, and Medtronic. The study was designed and conducted, analyzed, and interpreted by the investigators independently of all sponsors. Dr. Olthuis reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.