Background: The treatment of acute ischemic stroke has evolved over the past several years to utilize neuroimaging in guiding therapy. With regard to IV tPA and thrombectomy, recent endovascular therapy trials have utilized the ASPECT score in determining if intervention should be attempted. We sought to evaluate different regions of interest on the ASPECT score to determine if specific areas of injury should be weighed more heavily during decision making.
Methods: We evaluated the pre-intervention CT scans of the head on all patients who received IV tPA and mechanical thrombectomy during the last two years at a community based, university affiliated comprehensive stroke center. All 20 regions of interest (ROIs) of the ASPECT score were compared with each other with regard to initial NIH stroke score, discharge NIHSS, delta NIHSS and modified Rankin Score to determine if one or more regions were associated with worse outcome. SPSS version 22 was used to determine Spearman rho values and paired samples t-test.
Results: A total of 864 patients presented with acute ischemic stroke, of which 70 patients received IV tPA followed by mechanical thrombectomy and were included in the study. The 4 ROIs with the greatest correlation with worse outcome as rated by discharge mRS were the right and left M5-M6 [4.2 (p=.001, 95%CI 3.5-4.8); 4.3 (p=.001, 95%CI 3.4-5.1); 4.3 (p=.001, 95%CI 3.4-5.2); 4.2 (p=.001, 95%CI 3.6-4.8), respectively].
Conclusion: Early changes defined as hypodensity in the M5 and M6 ROIs on either side of the pre-intervention head CT were associated with significantly worse outcomes. A modified ASPECT score should be considered to better prognosticate patients and guide the appropriateness of endovascular therapy in select patients. These findings should be validated in a larger population and a longer follow-up period.