Outcome Analysis of MRI-based Thrombolytic Therapy in Acute Stroke: Can MRI Expand the Time Window for Thrombolytic Therapy?

Jeon, Sang Beom; Kwon, Sun Uck; Kwon, Jee Hyun; Suh, Dae Chul; Choi, Choong Gon; Kim, Jong S

Abstract

BACKGROUND
We attempted to see if acute MRI can expand the time window of thrombolytic therapy in acute stroke. METHODS: We performed MRI protocol including diffusion-weighted image (DWI) and MR angiogram (MRA) for patients with stroke within 6 hours after symptom onset. We selected 58 patients who had occlusion of middle cerebral artery (MCA) on the initial MRA. Thrombolytic therapy was done only when the patients showed more severe neurological deficits than expected with DWI findings. We analyzed demographic features, initial and follow-up NIH stroke scale scores, recanalization, and hemorrhagic transformation after thrombolytic therapy in 2 groups which were classified according to time to check MRI (within or beyond 3 hours). We measured the initial and follow-up lesion volume detected by DWI. RESULTS: Thrombolytic therapy was done in 38 patients. Twenty-four patients underwent MRI within 3 hours, and 14 patients underwent MRI between 3 and 6 hours. There were no significant differences in baseline characteristics, recanalization rate, ratio of marked clinical improvement, and hemorrhagic transformation rate between 2 groups. Young age was a significant predictable factor for good clinical outcome (p<0.05), but the interval from onset to imaging time and treatment modalities were not. CONCLUSIONS: It is suggested that patients' age and DWI findings are more appropriate factors affecting the clinical outcome after thrombolytic therapy than time interval itself at least when the therapy is considered within 6 hours.