Clinical outcomes of isolated deep grey matter infarcts after endovascular treatment of large vessel occlusion stroke

A cortically-weighted versus total Alberta Stroke Program Early Computed Tomography Score in thrombectomy outcome models

OBJECTIVES

Individual subcortical infarct scoring for the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) can be difficult and is subjected to higher inter-reader variability. This study compares performance of the 10-point ASPECTS with a new 7-point cortically-weighted score in predicting post-thrombectomy functional outcomes.

MATERIALS AND METHODS

Prospective registry data from two comprehensive stroke centers (Site 1 2016-2021; Site 2: 2019-2021) included patients with either M1 segment of middle cerebral artery or internal carotid artery occlusions who underwent thrombectomy. Two multivariate proportional odds training models utilizing either 10-point or 7-point ASPECTS predicting 90-day shift in modified Rankin score were generated using Site 1 data and validated with Site 2 data. Models were compared using multiclass receiver operator characteristics, corrected Akaike's Information Criterion, and likelihood ratio test.

RESULTS

Of 328 patients (Site 1 = 181, Site 2 = 147), median age was 71y (IQR 61-82), 119 (36%) had internal carotid artery occlusions, and median 10-point ASPECTS was 9 (IQR 8-10). There was no difference in performance between models using either total or cortically-weighted ASPECTS (p=0.14). Validation cohort data were correctly (i.e., predicting modified Rankin score within one point) classified 50% (cortically-weighted score model) and 56% (total score model) of the time.

CONCLUSIONS

The 7-point cortically-weighted ASPECTS was similarly predictive of post-thrombectomy functional outcome as 10-point ASPECTS. Given noninferior performance, the cortically-weighted score is a potentially reliable, but simplified, alternative to the traditional scoring paradigm, with potential implications in automated image analysis tool development.

Endovascular thrombectomy for acute ischemic stroke

This review describes the evolution of endovascular treatment for acute ischemic stroke, current state of the art, and the challenges for the next decade. The rapid development of endovascular thrombectomy (EVT), from the first attempts into standard of care on a global scale, is one of the major achievements in modern medicine. It was possible thanks to the establishment of a scientific framework for patient selection, assessment of stroke severity and outcome, technical development by dedicated physicians and the MedTech industry, including noninvasive imaging for patient selection, and radiological outcome evaluation. A series of randomized controlled trials on EVT in addition to intravenous thrombolytics, with overwhelmingly positive results for anterior circulation stroke within 6 h of onset regardless of patient characteristics with a number needed to treat of less than 3 for any positive shift in outcome, paved the way for a rapid introduction of EVT into clinical practice. Within the "extended" time window of 6-24 h, the effect has been even greater for patients with salvageable brain tissue according to perfusion imaging with a number needed to treat below 2. Even so, EVT is only available for a small portion of stroke patients, and successfully recanalized EVT patients do not always achieve excellent functional outcome. The major challenges in the years to come include rapid prehospital detection of stroke symptoms, adequate clinical and radiological diagnosis of severe ischemic stroke cases, enabling effective recanalization by EVT in dedicated angiosuites, followed by personalized post-EVT stroke care.