Prognostic Significance of Angiographically Confirmed Large Vessel Intracranial Occlusion in Patients Presenting With Acute Brain Ischemia

Abstract

Independent predictors of outcome for ischemic stroke include age and initial stroke severity. Intracranial large-vessel occlusion would be expected to predict poor outcome. Because large-vessel occlusion and stroke severity are likely correlated, it is unclear if largevessel occlusion independently predicts outcome or is simply a marker for stroke severity. A consecutive series of patients with suspected stroke or transient ischemic attack were imaged acutely with computed tomography angiography (CTA). CTAs were reviewed for intracranial large-vessel occlusion as the cause of the stroke. Baseline National Institutes of Health Stroke Scale (NIHSS) score, discharge modified Rankin score, and patient demographics were abstracted from hospital records. Poor neurological outcome was defined as modified Rankin score exceeding 2. Seventy-two consecutive patients with acute ischemic stroke were imaged with CTA. The median (range) time from stroke symptom onset to CT imaging was 183 minutes (25 minutes to 4 days). Median NIHSS score was 6 (1-32) and intracranial large-vessel occlusion was found in 28 (38.9%) patients. Fifty-six percent of patients had a good neurological outcome. In multivariate logistic regression analysis, two variables predicted poor neurological outcome: baseline NIHSS score (OR 1.21, 95% CI [1.07-1.37]) and presence of intracranial large-vessel occlusion (OR 4.48, 95% CI [1.19-16.9]). The predictive value of large-vessel occlusion on outcome was similar to an 8-point increase in NIHSS score. In patients presenting with acute brain ischemia, intracranial large-vessel occlusion independently predicts poor neurological outcome at hospital discharge, as does the presence of a high NIHSS score. Performing routine intracranial vascular imaging on acute stroke patients may allow for more accurate determination of prognosis and may also guide therapy.