Association of Computed Tomography Perfusion Parameters with 90-Day Functional Independence After Endovascular Thrombectomy

<b>Background/Objectives</b>: Recently, a novel CT perfusion (CTP) parameter, the compensation index (COMPI; ratio of 4 s delayed perfusion to 6 s delayed perfusion), was shown to correlate more strongly with digital subtraction angiographic collaterals than the cerebral blood volume index (CBVI) and hypoperfusion intensity ratio. <b>Methods</b>: We retrospectively analyzed all anterior circulation large vessel occlusion patients treated at multiple thrombectomy centers from January to December 2024 to determine the relationship of COMPI and other CTP parameters with the primary outcome: a 90-day modified Rankin Scale (mRS) score of 0-2. Univariable logistic regression was performed to assess the association between each CTP parameter and the primary outcome in the full cohort and in those achieving endovascular reperfusion (modified treatment in cerebral ischemia 2b-3). Multivariable logistic regression was performed to determine factors independently associated with a 90-day mRS score of 0-2. <b>Results</b>: 323 subjects (median age 69 [57-78] years, median of National Institutes of Health Stroke Scale 15 [10-19.5]) were included, of whom 146/302 (48.3%) were functionally independent at 90 days. The COMPI was not associated with the primary outcome in the univariate analysis. CBVI was the only CTP parameter independently associated with a 90-day mRS score of 0-2 in the full cohort (per 0.1-point increase, odds ratio 1.349, 95% confidence interval 1.099-1.655, <i>p</i> = 0.004) and in those achieving reperfusion. <b>Conclusions</b>: The COMPI was not associated with a 90-day mRS score of 0-2. CBVI was associated with independent neurological function in the full cohort and in reperfused patients, supporting its role as a CTP collateral biomarker and potential risk stratification tool before thrombectomy.