Pretreatment CTP collateral parameters predict good outcomes in successfully recanalized middle cerebral artery distal medium vessel occlusions

Background Distal medium vessel occlusions (DMVOs) account for a large percentage of vessel occlusions resulting in acute ischemic stroke (AIS) with disabling symptoms. We aim to assess whether pretreatment CT Perfusion collateral status (CS) parameters can serve as imaging biomarkers for good clinical outcomes prediction in successfully recanalized middle cerebral artery (MCA) DMVOs. Methods We performed a retrospective analysis of consecutive patients with AIS secondary to primary MCA-DMVOs who were successfully recanalized by mechanical thrombectomy (MT) defined as modified thrombolysis in cerebral infarction (mTICI) 2b, 2c, or 3. We evaluated the association between cerebral blood volume (CBV) index and hypoperfusion intensity ratio (HIR) independently with good clinical outcomes (modified Rankin score (mRS) 0-2) using Spearman rank correlation, logistic regression, and ROC analyses. Results From 8/22/2018 to 10/18/2022, 60 consecutive patients met our inclusion criteria (mean age 71.2 +– 13.9 years old [mean+-SD], 35 female). CBV index (r = –0.693, p < 0.001) and HIR (0.687, p = 0.7 ((OR 2.27 [6.94 – 21.23], p = 0.001)) and absence of prior stroke (0.13 [0.33 – 0.86]), p = 0.024) were independently associated with good outcomes. ROC analysis demonstrated good performance of CBV Index in predicting good 90-day mRS (AUC 0.73, p = 0.003) with a threshold of 0.7 for optimal sensitivity (71% [52.0-85.8%]) and specificity (76% [54.9 – 90.6%]). HIR also demonstrated adequate performance in predicting good 90-day mRS (AUC 0.77, p = 0.001) with a threshold of 0.3 for optimal sensitivity (64.5% [45.4-80.8%]) and specificity (76.0% [54.9–90.6%]). Conclusions A CBV index ≥ 0.7 and HIR < 0.3 are independently associated with good clinical outcomes in our cohort of AIS caused by MCA-DMVOs that were successfully treated with MT.