Extending the time window for thrombectomy in stroke patients

Reuters Health - 26/07/2021 - Endovascular thrombectomy (EVT) performed anytime between 6 and 24 hours of ischemic stroke is equally effective in patients who have either a clinical imaging mismatch profile or target perfusion imaging mismatch profile, new research shows.

The findings are based on a pooled analysis of 505 ischemic stroke patients who participated in six randomized controlled trials.

The cohort included 295 patients with a mismatch between clinical deficit versus the size of early infarct (clinical mismatch subgroup) and 359 patients with a mismatch in the size of perfusion lesion versus the size of early infarct (target perfusion mismatch subgroup).

In both subgroups, EVT was associated with reduced disability at 90 days versus no EVT, with an odds ratio of 3.57 (95% confidence interval: 2.29 to 5.57; P<.001) in the clinical mismatch subgroup and 3.13 (95% CI, 2.10 to 4.66; P=0.001) in the target perfusion mismatch subgroup.

"These findings support EVT as a treatment for patients meeting the criteria for either of the imaging mismatch profiles within the 6- to 24-hour interval," Dr. Gregory Albers, with Stanford University in California and colleagues said in JAMA Neurology.

Current guidelines recommend EVT either in the 6- to 16-hour window in patients with a target perfusion imaging mismatch profile or in the 6- to 24-hour window in patients with a clinical imaging mismatch profile.

The findings also suggest that the absence of either mismatch profile (undetermined imaging profile) may not benefit from EVT, although the analysis of this small subgroup (123 patients) was underpowered, Dr. Albers and colleagues say.

"The results are clear. Thrombectomy was associated with equal benefits among patients with the two mismatch profiles, not only for the entire six- to 24-hour window but also within each time tertile," writes Dr. Jean-Claude Baron with University of Paris, France, in a JAMA Neurology editorial.

"These findings were consistent whether three-month functional outcome was assessed as an ordinal scale or dichotomized into favorable vs unfavorable outcome. This important finding, derived from optimal RCT data sets, suggests that the target mismatch profile (ie, mismatch derived from perfusion imaging) can be safely applied not only in the 6- to 16-hour window but also in the 16- to 24-hour window," Dr. Baron says.

"Applying this finding to routine care would substantially increase the currently small proportion of patients presenting more than 6 hours after stroke onset who could receive this beneficial and reasonably safe therapy. This particularly applies to the patients in the 16- to 24-hour window who fulfill the target mismatch criteria, which are more inclusive than the clinical mismatch criteria."

"Therefore, it seems sensible that the results of the Albers et al study, and their implications, would be implemented in forthcoming international guidelines," Dr. Baron predicts.

Funding for this research was provided by a grant from Stryker Neurovascular. Several authors have disclosed financial relationships with the company.

SOURCE: https://bit.ly/3iObd5k and https://bit.ly/2UPFtEQ JAMA Neurology, online July 26, 2021.



Posted on 26 July 202127 July 2021