# Infarct Growth Rate Predicts Early Neurological Improvement in Ischemic Stroke After Endovascular Thrombectomy

## TL;DR

This study shows that the rate at which a stroke injury grows before treatment predicts how well patients recover after a specific type of stroke procedure.

## Contribution

The study introduces the infarct growth rate as a novel predictor of early neurological improvement after endovascular thrombectomy.

## Key findings

- Fast infarct growth rate is associated with lower odds of early neurological improvement.
- Each 5 mL/h increase in infarct growth rate reduces the odds of improvement by 7.3%.
- 36.6% of patients achieved early neurological improvement after the procedure.

## Abstract

Background and Purpose: The infarct growth rate (IGR) is a major modifier of the therapeutic effect of endovascular thrombectomy. The objective of this paper was to explore the utility of the IGR measured by perfusion the imaging in predicting early neurological improvement (ENI) of patients treated with EVT. Methods: We reviewed consecutive large vessel occlusive stroke in the anterior circulation and treated by thrombectomy between October 2019 to July 2024. The IGR was defined as the ischemic core volume (apparent diffusion coefficient ≤ 620 × 10−6 mm2/s or relative cerebral blood flow < 30%) divided by the time from stroke onset to imaging. ENI was defined as a reduction ≥ 6 points in the NIH Stroke Scale score at 24 h after the procedure, or an NIH Stroke Scale score of 0 or 1 on day 7 of hospitalization or at discharge if it occurred before day 7. Results: A total of 407 patients (mean age, 69.3 ± 12.5 years; 63.1% of male) were included, of whom 149 (36.6%) achieved ENI. Among all enrolled patients, 281 patients were classified as slow (IGR < 10 mL/h) and 126 fast progressors (IGR ≥ 10 mL/h). In multivariable analyses, fast progressors had a lower likelihood of achieving ENI after endovascular thrombectomy (odds ratio, 0.442; 95% confidence intervals, 0.269–0.729, p = 0.001) as compared to slow progressors. Subgroup analyses further confirmed these results. Furthermore, the odds of ENI decreased by 7.3% for each 5 mL/h increase in the IGR (odds ratio, 0.927; 95% confidence intervals, 0.875–0.982, p = 0.011). Conclusions: The present study found that the pre-treatment IGR was associated with ENI in thrombectomy patients.