Multivariable analysis of predictive factors related to outcome at 6 months after intra-arterial thrombolysis for acute ischemic stroke

Background and Purpose-Recent reports have suggested that a rapid assessmen t of pretreatment residual cerebral blood flow (CBF) could be used to optim ize selection criteria for thrombolysis in patients with acute ischemic str oke to improve clinical outcome. We investigated retrospectively residual C BF and other clinical factors related to outcome at 6 months after intra-ar terial thrombolysis by using multivariable analysis. Methods-Seventy-six patients received intra-arterial thrombolysis within 6 hours of symptom onset. The multiple regression method was used to analyze associations between the modified Rankin scale (MRS) at 6 months after trea tment and clinical factors including age, infarction type, duration of isch emia, dose of urokinase, degree of recanalization, hemorrhage, National Ins titutes of Health Stroke Scale score (NIHSSS), and residual CBF evaluated b y pretreatment single-photon emission-computed tomography; these values wer e assessed with the use of the regional-to-cerebellar activity (R/CE) ratio of ischemic region to cerebellum and asymmetry index. Results-MRS at 6 months was good (0 to 3) in 65% and poor (4 to 6) in 35%. Factors significantly related to MRS at 6 months were R/CE ratio (P<0.0001) , NIHSSS at baseline and the following day (P<0.0001), cardioembolic infarc tion (P=0.0014), age (P=0.0074), and recanalization grade (P=0.007), NIHSSS of >20, R/CE ratio of <0.35, cardioembolic infarction, incomplete recanali zation (grade <3), and older age (>75 years) were determined to be signific ant independent predictors of poor outcome. Conclusions-The residual CBF, neurological score at baseline and the follow ing day, age, and recanalization grade correlated significantly with long-t erm outcome. The NIHSSS of >20 and R/CE ratio of <0.35 were determined to b e significant independent predictors of poor outcome by multivariable analy sis.