By Dr Fong Man Chi, Natalie, TMH
Background: Thepredictors of early adverse outcomes following intravenous thrombolysis or endovascular therapy for acute ischemic stroke are inadequately characterised among patients in Hong Kong. It is essential to identify early prognostic factors to clarify the therapeutic perspective.
Objective:To determine the clinical features observed in the first 24 hours post-intervention that predict early mortality and poor functional outcomes for stroke patients admitted to the intensive care unit.
Design:A retrospective cohort study.
Setting: ICU of an acute regional hospital in Hong Kong.
Subjects:Patients with acute ischemic stroke who were admitted to the ICU after intravenous thrombolysis or endovascular therapy between 1st June 2004 and 31st July 2013 were included in this study.
Outcomes:The primary outcome was all-cause mortality at 30 days. The secondary outcome was severe disability or death defined as modified Rankin scores (mRS) of 4 to 6 at 90 days.
Results: A totalof 204 ICU patients (median age, 67 years) were included in the study; 164 patients were treated with intravenous thrombolysis alone, and 40 patients were treated with endovascular intervention. The 30-day all-cause mortality rate was 14.7% (n=30), and the 90-day all-cause mortality rate was 17.2% (n=35). 14 patients (6.9%) suffered from symptomatic intracranial haemorrhage. A higher score on the National Institute of Health Stroke Scale (NIHSS) at presentation (adjusted OR, 1.098; 95% CI, 1.012-1.191; p=0.018), a higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (adjusted OR, 1.246; 95% CI, 1.127-1.377; p<0.001) and higher first 24-hour systolic blood pressure (adjusted OR, 1.054; 95% CI, 1.09-1.019; p=0.003) independently predicted 30-day mortality regardless of treatment modality. Additionally, a higher NIHSS score (adjusted OR, 1.114; 95% CI 1.053-1.178; p<0.001) at presentation and a higher APACHE II score (adjusted OR, 1.12; 95% CI, 1.041-1.204; p=0.001) were independently associated with poor functional outcome (modified Rankin scores, 4-6). Endovascular therapy was associated with less functional dependence (adjusted OR, 0.232; 95% CI, 0.09-0.598; p=0.001), a significantly decreased requirement of temporary tracheostomy (p=0.027) and less development of in-hospital sepsis (p=0.030) despite a higher initial NIHSS score (median, 15 versus 12).
Conclusion:Prediction of stroke mortality and functional outcome can be performed as early as within the first 24 hours after receiving intravenous or endovascular therapy for acute ischemic stroke. Endovascular therapymay be superior to intravenous thrombolysis alone, in terms of functional outcome and stroke-related complications.