Noncontrast Computed Tomography Comparable Imaging Alternative for Detecting Late-Presenting Large-Vessel Occlusion

New findings published in JAMA Neurology suggest that noncontrast computed tomography (CT) can be an imaging alternative to select patients with late-presenting large-vessel occlusion for mechanical thrombectomy.

Researchers aimed “to compare the clinical outcomes of patients selected for mechanical thrombectomy by noncontrast computed tomography (CT) vs those selected by computed tomography perfusion (CTP) or magnetic resonance imaging (MRI) in the extended time window,” wrote Thanh N. Nguyen, MD, Department of Neurology, Boston University School of Medicine, Boston, Massachusetts, and co-researchers.

Through this multinational cohort study, Dr Nguyen et al screened 2304 patients across 15 sites and 5 countries for eligibility. A total of 1604 patients with proximal anterior circulation occlusion stroke that presented within 6 to 24 hours of time last seen well, from January 2014 to December 2020, were included.

Follow-up occurred 90 days following onset of stroke. Researchers assessed modified Rankin Scale scores after 90 days as the primary endpoint, with secondary endpoints being rates of 90-day functional independence, 90-day mortality, and symptomatic intracranial hemorrhage.

Of the 1604 patients, 532 were selected for mechanical thrombectomy by CT, 752 were selected for mechanical thrombectomy by CTP, and 318 were selected for mechanical thrombectomy by MRI.

Researchers did not find a difference in 90-day ordinal modified Rankin Scale scores between patients selected by CT vs CTP (adjusted odds ratio [aOR], 0.95 [95% CI, 0.77-1.17]; P = .64)

or CT vs MRI (aOR, 0.95 [95% CI, 0.8-1.13]; P = .55).  They also found rates of 90-day functional independence were similar between patients selected by CT vs CTP, but noted lower rates in patients selected by MRI than CT.

Reperfusion was more commonly successful in the CT and CTP groups compared with the MRI group. There were no significant differences in 90-day mortality or symptomatic intracranial hemorrhage noted between the groups.

“In patients undergoing proximal anterior circulation mechanical thrombectomy in the extended time window, there were no significant differences in the clinical outcomes of patients selected with noncontrast CT compared with those selected with CTP or MRI,” concluded Nguyen et al. “These findings have the potential to widen the indication for treating patients in the extended window using a simpler and more widespread noncontrast CT–only paradigm.”

Nguyen TN, Abdalkader M, Nagel S, et al. Noncontrast Computed Tomography vs Computed Tomography Perfusion or Magnetic Resonance Imaging Selection in Late Presentation of Stroke With Large-Vessel Occlusion. JAMA Neurol. Published online November 08, 2021. doi:10.1001/jamaneurol.2021.4082