Abstract TP92: When Less is More: Do We Need Advanced Perfusion Neuroimaging Prior to Mechanical Thrombectomy?

Abstract

Objective: To assess whether the choice of pretreatment neuroimaging has an impact on clinical outcomes following mechanical thrombectomy (MT). Background: Most MT trials required advanced neuroimaging including either CT or MR based perfusion studies for patient selection prior to randomization. However, in practice, centers may offer MT based on favorable findings (ASPECT score > 6) on non-contrast head CT (HCT) ± CT angiogram (CTA). We compared outcomes between patients who underwent MT based on HCT ± CTA (HCT- group) versus additional including CT or MR perfusion scan (HCT+ group). Design/Methods: Case records of all patients who underwent MT at our center between Jun 2012 - Jun 2017 were reviewed. Patient demographics, risk factors, presentation, pretreatment scan findings, treatment times and clinical outcomes were compared. Favorable outcome is defined as mRS of 2 or less at 90-days. Results: A total of 528 patients were identified, of which 46.4% were male. There were 385 (72.9%) patients who underwent MT based on findings on HCT or CTA (HCT-); while the remaining 143 (27.1%) also underwent additional CTP (121/528; 22.9%) or MRI perfusion (22/528; 4.2%) prior to MT (HCT+). Median age (73 vs 72, p=0.1) and baseline ASPECT scores (8.4 vs. 8.3, p=0.5) were comparable. The HCT- patients had higher NIHSS (17.8 vs. 15.3, p<0.01) and presented earlier with faster onset-to-onsite arrival time (241 vs. 476 minutes, p<0.01). Also, rate of TICI 2b/3 recanalization was higher in the HCT- group (82.8 vs 71.5, p<0.01); however favorable outcome rates were comparable (44.6 vs 47.4, p=0.6). Conclusions: Our findings suggest that HCT ± CTA based MT selection may achieve similar outcomes as compared to more advanced perfusion based neuroimaging protocols. Further prospective studies are warranted.