Early infarct growth rate is associated with symptomatic intracranial hemorrhage after endovascular thrombectomy.

Background: Time elapsed from stroke onset and baseline infarct volume is influential on endovascular thrombectomy (EVT) outcomes.

Objectives: This study aimed to explore the utility of early infarct growth rate (EIGR) measured by apparent diffusion coefficient (ADC) in predicting symptomatic intracranial hemorrhage (sICH) of ischemic stroke patients after EVT.

Methods: We retrospectively analyzed patients from the prospectively maintained stroke registry admitted between January 2019 and March 2023, presenting with large vessel occlusive stroke in the anterior circulation. EIGR was defined as ischemic core volume on magnetic resonance perfusion imaging (ADC ⩽620 × 10^-6 mm²/s) divided by the time from stroke onset to imaging. sICH was diagnosed according to the Heidelberg Bleeding Classification within 72 h after the procedure.

Results: A total of 315 patients met the inclusion criteria. We observed sICH in 36 (11.4%) patients. After adjusting for the potential confounders, increased EIGR was confirmed to be independently associated with a higher risk of sICH (adjusted odds ratio, 1.033; 95% confidence interval (CI), 1.018-1.048; p = 0.001). Similar results were also confirmed when EIGR was analyzed as a categorical variable. Using a logistic regression model with restricted cubic splines, we found a linear correlation between EIGR and sICH risk (p = 0.001 for linearity). Furthermore, adding EIGR to a model containing conventional risk factors significantly improved risk reclassification for sICH (category-free net reclassification index, 0.393; 95% CI, 0.227-0.560; p = 0.001; integrated discrimination improvement, 0.245; 95% CI, 0.146-0.343; p = 0.001).

Conclusion: Increased EIGR may predict the sICH in ischemic stroke patients who receiving EVT.