Outcomes of Mechanical Thrombectomy for Stroke Patients with Low Alberta Stroke Program Early CT Score

Background

Acute ischemic stroke is a life-threatening disease, and large vessel occlusion is one of the major causes of severe disability. Mechanical thrombectomy (MT) has become the standard treatment for acute ischemic stroke, with multiple clinical trials demonstrating its efficacy and safety within the time window. However, the benefit of MT for patients with a large early ischemic lesion has been controversial. Recently, several large clinical studies have evaluated the efficacy of MT in these patients, with encouraging results, but data for different time windows are limited.

Study Process

The aim of this study was to compare the outcomes of MT between patients with low Alberta Stroke Program Early CT Score (ASPECTS 2-5) within 6 hours and 6-24 hours after stroke onset. The researchers retrospectively analyzed data from 10,229 MT patients in the STAR (Stroke Thrombectomy and Aneurysm Registry) multicenter international registry database from 2013-2023, and selected 274 eligible patients, who were divided into early and late groups by propensity score matching.

The study comprehensively documented patient demographics, medical history, stroke onset time, surgical methods, and post-operative conditions. It evaluated outcome measures such as the modified Rankin Scale (mRS) score at 90 days, mortality rate, and recanalization rate, and performed multivariable logistic regression analysis to investigate factors associated with prognosis.

Key Findings

1. After propensity score matching, there were no statistically significant differences in baseline characteristics such as age, gender, medical history, and baseline NIHSS scores between the two groups.

2. There were no significant differences in the proportions of patients achieving mRS 0-2 and mRS 0-3 at 90 days after thrombectomy between the two groups (14.3% and 31.0% in the early group, 19.0% and 33.3% in the late group, P>0.05).

3. Patients in the early group had a higher risk of symptomatic intracranial hemorrhage (22.9% vs. 10.8%, OR=2.44, P=0.04).

4. There were no significant differences in 90-day mortality, recanalization rate, and other outcome measures between the two groups.

5. Younger age, lower baseline NIHSS score, absence of cervical internal carotid artery occlusion, and successful recanalization (mTICI≥2b) were associated with better functional outcomes (90-day mRS 0-3).

Significance

This large real-world study demonstrated that for patients with low ASPECTS scores, functional outcomes were comparable whether MT was performed within 6 hours or between 6-24 hours after stroke onset, supporting the appropriate extension of the MT time window. However, it is noteworthy that the early group had a higher risk of symptomatic intracranial hemorrhage, which may be related to poorer collateral circulation. Clinicians should weigh the expected benefits and bleeding risks when making treatment decisions. This study provides a basis for individualized treatment strategies.

This research has significant clinical and academic value, contributing to the optimization of MT indications across different time windows and enabling more patients to benefit. The scientific data analysis is rigorous, and the conclusions are reasonable and credible, warranting clinical promotion.