Intravenous thrombolysis for acute cerebral ischaemia: comparison of outcomes between patients treated at working versus nonworking hours

Abstract

Background: Stroke outcomes are worse in patients admitted at nonworking hours (NWH), but whether this is also true in patients treated with intravenous (i.v.) thrombolysis has not been definitely proven.

Objective: Our aim was to test the hypothesis that stroke patients treated by i.v. rt-PA at NWH have a worse outcome than those treated at working hours (WH).

Methods: We compared outcomes at 7 days and at 3 months, between patients treated at NWH and at WH in the stroke unit of the Lille University Hospital.

Results: Of 252 consecutive patients [median age: 69 years; 132 men (52.4%); median National Institutes of Health Stroke Scale score: 14; median onset-to-needle time: 150 min], 134 (53.2%) were treated at NWH. They did not differ for baseline characteristics and proportion of patients with modified Rankin Scale scores 0-1 and 0-2 at 3 months. Patients treated at WH were more likely to die before 7 days (12.7 vs. 4.5%; adjusted odds ratio: 3.6; 95% confidence interval: 1.2-10.4) and at 3 months (21.6 vs. 11.4%; adjusted odds ratio: 2.2; 95% confidence interval: 1.02-4.7). The causes of death did not differ between NWH and WH. At NWH, there was no difference in baseline characteristics and outcomes of patients treated by stroke- and nonstroke neurologists.

Conclusion: The case fatality rates were unexpectedly higher at WH than at NWH. If this finding can be reproduced and is not a chance finding, we should identify explanations, especially organisational issues, chronobiological factors or summation of subtle--nonsignificant--baseline differences.