A case-control analysis of intra-arterial urokinase thrombolysis in acute cardioembolic stroke

BACKGROUND: Intra-arterial urokinase (IA-UK) thrombolysis is frequently given in Japan to selected patients with acute cerebral artery occlusion. However, it is not clear whether or not IA-UK thrombolysis has an efficacy for acute stroke patients. The purpose of this study was to assess the effects of IA-UK thrombolysis in acute cardioembolic stroke patients, by performing a case-control analysis using data from Japan's Multicenter Stroke Investigator's Collaboration (J-MUSIC). METHODS: 16,922 acute ischemic stroke patients were enrolled into J-MUSIC. From these patients, we selected 91 patients (UK group) who met the following criteria: treatment with IA-UK; 20-75 years of age; cardioembolic stroke; presenting with a carotid stroke; admission within 4.5 h of symptom onset, and a National Institutes of Health Stroke Scale (NIHSS) score of 5-22 points on admission. A control group of 182 patients without IA-UK treatment and matched to the NIHSS score, gender, and age was chosen. We compared the modified Rankin scale (mRS) score at discharge and the mortality between the 2 groups. RESULTS: In both groups, the mean age was 65 +/- 8 years, and the median NIHSS score was 14. The mean interval between symptom onset and UK administration was 3.4 +/- 1.3 h, and the IA-UK dose was 392,000 +/- 200,000 units. The mRS score at discharge was lower in the UK group than in the control group (mean, SD, median; 2.8, 2.9, 2 in UK group vs. 3.3, 1.8, 4, in the control, respectively p = 0.031). A favorable outcome (mRS of 0-2) was more frequently observed in the UK group (50.5%) than in the control group (34.1%, p = 0.0124). No difference in the mortality rate was seen between the UK group (11.0%) and the control group (13.3%). As well, there was no difference in the length of hospital stay between the UK group (46 +/- 41 days, mean +/- SD) and the control group (42 +/- 42 days, mean +/- SD). CONCLUSIONS: IA-UK thrombolytic therapy may improve the outcome in hyperacute cardioembolic stroke patients.