in a new study.
The phase 2b CHOICE study was presented at the International Stroke Conference by Ángel Chamorro, MD, University of Barcelona, who received a round of applause as the results were revealed.
The study was also published online in JAMA to coincide with the presentation at the ISC.
The main results showed a remarkable and significant 18.4% absolute increase in the number of patients achieving an excellent neurologic outcome, defined as modified Rankin Scale (mRS) score of 0-1, after treatment with intra-arterial alteplase immediately following thrombectomy. This was despite the fact that the study was stopped early because of difficulty obtaining placebo supplies during the pandemic, having only enrolled 121 of the planned 200 patients.
This benefit was achieved without any increase in intracranial hemorrhage, which Dr. Chamorro described as “reassuring.”
He explained that although mechanical thrombectomy gives a high rate of successful reperfusion, only about 27% of patients achieve complete freedom of disability (mRS 0-1) at 3 months. He suggested that this may be the result of impaired reperfusion of the microcirculation despite complete recanalization of the occluded vessel.
The researchers postulated that thrombi could persist within the microcirculation in patients with normal or nearly normal cerebral angiograms at the end of thrombectomy and that these smaller thrombi may be dissolved by a dose of intra-arterial thrombolysis.
‘Dramatic and exciting results’
The CHOICE study was greeted with enthusiasm from commentators at the ISC meeting, which was presented by the American Stroke Association, a division of the American Heart Association. Louise McCullough, MD, chair of the late-breaking science session at which the study was presented and ISC program chair, described the results as “very dramatic and very exciting.”
“The CHOICE trial is going to be a highlight of the meeting because it could change care now,” Dr. McCullough said. “By just giving a little adjunctive tPA after the main clot is out, everybody seems to benefit, and there was no increased risk in bleeding. I think that’s the one that people are going to take back to their practice. But it was a very small trial, so you have to be cautious.”
And Peter Panagos, MD, professor of emergency medicine and neurology at Washington University School of Medicine, St. Louis, said: “It’s great to see this study. The 18% treatment effect is very impressive.”
Dr. Panagos added: “This study addresses a well-described finding from many of the interventional trials, that despite excellent outcomes in recanalization, patients don’t do as well as predicted. The thought is that either re-stenosis or propagation of smaller clots downstream from the original clot in small-caliber vessels [is what] causes additional, unintended damage. The use of intra-arterial thrombolysis after recanalization may assist in dissolving those smaller, downstream clots and debris and improve outcomes.”
But he pointed out that enthusiasm over these results must be matched with some concerns, including the small study size and wide confidence intervals – so larger, randomized studies will be required to confirm and change current clinical practice.