Hypoperfusion ratio predicts infarct growth during transfer for thrombectomy

Abstract

We hypothesized that automated assessment of collaterals on computed tomography perfusion can predict the rate of infarct growth during transfer from a primary to a comprehensive stroke center for endovascular stroke treatment. We identified consecutive patients (N = 28) and assessed their collaterals based on the hypoperfusion intensity ratio (HIR) prior to transfer. Infarct growth rate was strongly correlated with HIR (r = 0.78, p < 0.001). Receiver operating characteristic analysis identified HIR ≥ 0.5 as optimal for predicting infarct growth. Patients with HIR ≥ 0.5 had a median infarct growth rate of 10.1ml/h (interquartile range [IQR] = 6.4-18.4) compared with 0.9ml/h (IQR = 0-2.8; p < 0.001) in patients with HIR < 0.5. Patients with HIR ≥ 0.5 had an 83% probability of significant core growth, whereas patients with HIR < 0.5 had an 88% probability of core stability. These preliminary data have the potential to guide decision making regarding whether repeat brain imaging should be performed after transfer to a comprehensive stroke center. Ann Neurol 2018;84:616-620.