Clinical and MRI Predictors of No Early Recanalization Within 1 Hour After Tissue-Type Plasminogen Activator Administration

Background and Purpose— The aim of the present study was to investigate independent clinical and MRI factors associated with no early recanalization within 1 hour after tissue-type plasminogen activator (tPA) administration. Methods— Patients with acute stroke within 3 hours of onset who were treated with tPA were studied prospectively. Patients with internal carotid artery, M1, and M2 occlusion were enrolled, and independent clinical and MRI factors associated with no early recanalization within 1 hour after tPA administration were examined using multivariate logistic regression analysis. Results— One hundred thirty-two patients (63 men; mean age, 76.4±10.2 years; internal carotid artery occlusion in 37 patients, M1 occlusion in 58, and M2 occlusion in 37) were enrolled. Follow-up MR angiography within 60 minutes after tPA infusion revealed early recanalization in 49 (37.1%) patients (complete in 16 patients, partial in 33) and no recanalization in 83 (62.9%). Using 8 variables (atrial fibrillation, time from stroke onset to treatment ≥140 minutes, use of warfarin, glucose ≥135 mg/dL, large artery diseases, internal carotid artery occlusion, M1 occlusion, and M1 susceptibility vessel sign on T2*) identified on univariate analysis at P <0.2, multivariate logistic regression analysis revealed that M1 susceptibility vessel sign was the only independent factor associated with no early recanalization (OR, 7.157; 95% CI, 1.756 to 29.172; P =0.006). The sensitivity, specificity, positive predictive value, and negative predictive value of M1 susceptibility vessel sign for predicting no early recanalization were 31.3%, 93.9%, 89.7%, and 44.7%, respectively. Conclusions— Of clinical and MRI factors before tPA infusion, M1 susceptibility vessel sign on T* is the only independent factor associated with no early recanalization within 1 hour after tPA administration.