Thrombolysis for acute ischemic stroke: do patients treated out of hours have a worse outcome?

Introduction: Previous studies on the impact of nonworking hours (NWH) have produced conflicting results. We aimed to compare the time to treatment with thrombolysis between NWH and working hours (WH) at an Australian comprehensive stroke center.

Materials And Methods: All acute ischemic stroke patients treated with intravenous alteplase (IV-alteplase) from January 2003 to December 2011 at the Royal Melbourne Hospital were included. Data collected included demographics, serial time points (including onset, presentation to emergency department, neuroimaging, and thrombolysis), and clinical outcomes (modified Rankin Scale [mRS] and death) at 3 months. NWH were defined as weekdays 5 PM-8 AM, weekends, and public holidays. Comparisons were made in the door-to-computed tomography (CT) time, the door-to-needle time, mRS, and mortality within 3 months between the NWH group and WH group.

Results: We recruited 388 consecutive patients who received IV-alteplase, 226 patients were in NWH and 162 patients in WH. The median age was 71 years (Interquartile range [IQR] = 60-79), 54.1% of patients were male, and the median National Institutes of Health Stroke Scale score was 13 (IQR = 8-18). No significant differences were observed at baseline between the NWH and WH groups except for prior stroke. There was a 15-minute increase in the median door-to-needle time (80 minutes in the NWH group versus 64.5 minutes in the WH group, 95% confidence interval [CI]: 6.36-23.64, P = .001). No significant differences were noted in the median door-to-CT time (95% CI: -1.16 to 9.16, P = .128) and clinical outcomes at 3 months (P > .05). Both the door-to-CT time and the door-to-needle time became shorter over the period of the study (P < .001).

Conclusions: Our study showed that the "NWH effect" increased the door-to-needle time. The patients treated out of hours did not have a worse outcome.