Early partial recanalization after intravenous thrombolysis leads to prediction of favorable outcome in cases of acute ischemic stroke with major vessel occlusion.

We investigated the association between early recanalization degree after intravenous thrombolysis (IVT), occurrence of hemorrhagic transformation, and functional outcome. We also evaluated whether recombinant tissue plasminogen activator (rTPA) dosing error could influence the outcome. Patients with ischemic stroke with major vessel occlusion (n=256) who underwent IVT were included. Recanalization status (no recanalization, partial recanalization, and complete recanalization) was confirmed by subsequent magnetic resonance or conventional angiography. Association between early recanalization degree and favorable outcome (modified Rankin Scale score ≤2) was evaluated using logistic regression analysis. Early partial recanalization was achieved in 33 (12.9%), and complete recanalization in 7 (2.7%) patients. Patients with the highest quintile of rTPA dosage achieved complete recanalization more frequently than the lower four quintiles (8.0% vs 2.0%, P=0.03). Hemorrhagic transformation tended to occur more frequently in patients with complete recanalization as compared with patients with partial recanalization (57.1% vs 21.2%, P=0.15). The proportion of favorable outcome was significantly lower in patients with the highest quintile of rTPA dosage used as compared with the patients with lower four quintiles (40.8%, 57.0%, P=0.04). In multivariable analysis, partial recanalization was significantly associated with favorable outcome (adjusted odds ratio, 3.15; 95% CI, 1.06-9.35), but complete recanalization was not. Early partial recanalization after IVT may be an indicator of favorable outcome with low occurrence of any hemorrhagic transformation.