Association of hypoperfusion intensity ratio and cerebral blood volume Index with good outcome in patients transferred for thrombectomy.

BackgroundHypoperfusion intensity ratio (HIR) and cerebral blood volume index (CBVI) have been shown to predict clinical outcome, but further validation is needed in patients initially presenting to non-thrombectomy centers.MethodsWe conducted a retrospective study of patients with an anterior circulation large vessel occlusion (ACLVO) who underwent computed tomography perfusion (CTP) scanning at a non-thrombectomy center and were transferred for consideration of thrombectomy. We evaluated the association of three measures of collateral status (HIR, CBVI, and a collateral score combining both measures) to 90-day modified Rankin scale (mRS).ResultsWe identified 497 eligible patients, of whom 93% underwent thrombectomy. After adjusting for covariates, ascending numerical CBVI was associated with 90-day mRS ≤ 2 in both overall patients and the recanalized subgroup ( = 436). In the recanalized subgroup, 90-day mRS ≤ 2 among patients with CBVI > 0.7 was 56% versus 36% with CBVI ≤ 0.7 [adjusted OR: 1.73 (1.13-2.65),  = 0.012]. Neither HIR thresholds below 0.4, 0.5, and 0.6, nor a good versus poor collateral score, were associated with independent or improved functional outcome,.ConclusionIn this study of ACLVO patients transferred for thrombectomy consideration, ascending numeric CBVI was associated with independent function in both the overall population and the recanalized subgroup, and CBVI > 0.7 was associated with both independent and improved functional outcome in recanalized patients. Among CTP measures of collateral status, CBVI alone may play an important role in stroke prognostication and management for ACLVO patients who initially present to a non-thrombectomy center.