Predictive Factors for Early Clinical Improvement after Intra-arterial Thrombolytic Therapy in Acute Ischemic Stroke

Background In acute ischemic stroke, the speed of improvement after intra-arterial thrombolytic therapy (IAT)–mediated recanalization varies. This study aimed to identify clinical and radiological variables that are predictive of early improvement (EI) after IAT in acute ischemic stroke. Methods This single-center retrospective cohort study included 141 consecutive patients who underwent IAT for terminal internal carotid and/or middle cerebral artery (MCA) occlusions. EI was defined as a National Institutes of Health Stroke Scale (NIHSS) score less than 3 or NIHSS score improvement of 8 points or more within 72 hours of IAT. The EI and non-EI groups were compared in terms of clinical and radiological findings before and after IAT. Results Forty-nine patients showed EI (34.8%). Multivariate analysis revealed that atrial fibrillation (odds ratio [OR] .35, 95% confidence interval [CI] .14-.89, P = .028) and hyperdense MCA sign (OR .39, CI .15-.97, P = .042) were related with lack of EI. The independent EI predictors were less extensive parenchymal lesion on baseline computed tomography (OR 4.92, CI 1.74-13.9, P = .003), intermediate to good collaterals (OR 3.28, CI 1.16-9.31, P = .026), and recanalization within 6 hours of symptom onset (OR 5.2, CI 1.81-14.94, P = .002). EI associated with favorable outcomes (modified Rankin scale score 0-2) at discharge (88% versus 7%; P