Neurological

CT without contrast medium for mechanical thrombectomy in the extended time window: the results

In patients who underwent mechanical thrombectomy of the proximal anterior circulation in the extended time window, no difference was observed between contrast-free computed tomography (NCCT) and advanced imaging techniques. These results were published in JAMA Neurology.

Advanced imaging is currently recommended for patient selection. However, access to these modalities is still limited in all stroke centers. The current aim of the study was to compare the clinical outcomes of patients selected for mechanical thrombectomy by NCCT with those selected by computed tomography perfusion (CTP) or magnetic resonance imaging (MRI) in the expanded window.

The late endovascular reperfusion (CLEAR) CT study was a multicenter cohort study conducted between 2014 and 2020 at 15 sites in 5 countries. Patients (N = 1604) with stroke in the proximal anterior circulation who underwent mechanical thrombectomy in the extended time window were selected for NCCT, CTP or MRI. The extended time window was defined as 6-24 hours between the last well-seen time and the arterial puncture. Successful reperfusion was defined by the modified treatment for cerebral infarction (mTICI) on a scale of 2b-3.

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The median patients were 70 years old (interquartile range [IQR], 58.5-80) years, 52.9% were men, 70.7% had high blood pressure, 32.9% atrial fibrillation and 23.9% diabetes. Among the 534 who underwent NCCT, 752 CTP, and 318 MRI, baseline groups differed significantly on National Institutes of Health Stroke Scale (NIHSS), transfer status, and occlusion site (all P <0.001).

The last clearly visible puncture was shortest in the NCCT cohort (median 10.4; IQR 7.8-14.4 h), followed by CTP (median 11.3; IQR 8.4-15.2 h) and MRI (median 12.4; IQR 9.4-15.4 h; P <.001). In the non-relocated patients, the time from arrival at the endovascular center to puncture at NCCT (median 76; IQR 50-107 min) was shortest, followed by CTP (median 93; IQR 72-118 min) and MRI (median 98; IQR 50-107 min). IQR 78-135 min; p <.001).

In more CTP (89.5%) and NCCT (88.9%) recipients, successful reperfusion was achieved compared to MRI (78.9%; P <0.001).

NIHSS scores at discharge were lower in CTP (median 6; IQR 2-14) and NCCT (median 7; IQR 3-17) than in MRI recipients (median 11; IQR 3-19) (P <.001 ).

The 90-day mortality ranged from 19.5% to 23.4% (P = 0.38).

Early CT scores from the Alberta Stroke Program (ASPECTS; odds ratio [OR], 1.17; P <.001), age (OR, 0.97; P <.001), baseline NIHSS (OR, 0.90; P <.001), transfer status (OR, 0.79; P = .02), MRI (OR, 0.79; P = .03), diabetes (OR, 0.72; P = .01) and modified Rankin scale (mRS) of 1 (OR, 0.70; P = .01) or 2 (OR, 0.40; P <.001).

Predictors for a shift in the ordinal mRS score after 90 days were ASPECTS (OR, 1.18; P <0.001), age (OR, 0.97; P <0.001), baseline NIHSS (OR, 0.91; P < 0.001), internal carotid artery occlusion (OR, 0.83; P = 0.049), transfer status (OR, 0.79; P = 0.002) and baseline mRS of 1 (OR, 0.68; P = 0.001) or 2 (OR, 0.48; P <. 001).

This study was limited by its strict inclusion criteria, which were mRS 0-2, occlusion location, and median ASPECTS of 8.

Patients who underwent mechanical thrombectomy of the proximal anterior circuit in the extended time window for large vessel occlusion did not have significantly different results based on NCCT compared to advanced imaging.

“In patients who underwent mechanical thrombectomy of the proximal anterior circulation in the extended time window, there were no significant differences in the clinical outcomes of patients selected with CT without contrast compared to those selected with CTP or MRI “Concluded the researchers.

Disclosure: Several authors stated links to industry. For a full list of the details, see the original article.

relation

Nguyen TN, Abdalkader M, Nagel S, et al. Contrastless computed tomography vs. computed tomography Perfusion or magnetic resonance tomography selection for the late presentation of a stroke with large vessel occlusion. JAMA Neurol. November 8, 2021. doi: 10.1001 / jamaneurol.2021.4082

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