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Optimized Management of Endovascular Treatment for Acute Ischemic Stroke
Published on: January 18, 2018
Effect of alteplase on the CT hyperdense artery sign and outcome after ischemic stroke
Grant Mair1, Rüdiger von Kummer1, Zoe Morris1
1From the Division of Neuroimaging Sciences (G.M., Z.M., A.J.F., G.C., J.M.W.) and the Division of Clinical Neurosciences (P.A.G.S.), University of Edinburgh, UK; the Department of Neuroradiology (R.v.K.), Dresden University Stroke Centre, Germany; Danderyd Hospital (A.v.H.), Stockholm, Sweden; Neuroradiology (N.B.), James Cook University Hospital, Middlesborough, UK; School of Pathology and Laboratory Medicine (L.C.), University of Western Australia, Perth; Cliniques Universitaires St Luc (A.P.), Neurologie, Belgium; Stroke Center (A.A.), Sacro Cuore-Don Calabria Hospital, Negrar, Italy; the Department of Neuroradiology (G.P.), Salford Royal NHS Foundation Trust, Manchester, UK; and the Westmead Hospital Clinical School and The George Institute for Global Health (R.I.L.), University of Sydney, Australia.
Insights
Intravenous alteplase effectively reduces the hyperdense artery sign (HAS) in ischemic stroke patients, improving outcomes regardless of HAS characteristics. This treatment promotes independence at six months for all patients treated within six hours.
Area of Science:
- Neurology
- Radiology
- Clinical Trials
Background:
- The hyperdense artery sign (HAS) on computed tomography (CT) indicates intra-arterial thrombus in acute ischemic stroke.
- The impact of HAS location and extent on treatment response to intravenous alteplase remains incompletely understood.
Purpose of the Study:
- To determine if the location and extent of the CT hyperdense artery sign (HAS) influence the effectiveness of intravenous alteplase therapy.
- To analyze the association between HAS characteristics, alteplase treatment, and 6-month functional outcomes in the Third International Stroke Trial (IST-3).
Main Methods:
- CT scans from the IST-3 trial were evaluated by masked raters for HAS presence, location, and extent at baseline and follow-up (24-48 hours).
- Changes in HAS (growth, persistence, shrinkage, disappearance) were assessed, along with their correlation with 6-month functional outcomes (Oxford Handicap Scale).
- Statistical analyses, including ordinal regression, were used to evaluate the effect of HAS characteristics and alteplase treatment on outcomes.
Main Results:
- HAS presence independently predicted poorer 6-month functional outcomes.
- More extensive HAS was associated with worse outcomes, but HAS location (proximal vs. distal) did not significantly affect outcomes.
- Intravenous alteplase treatment led to a significant reduction (shrinkage/disappearance) in HAS at follow-up.
- Alteplase demonstrated a benefit in improving functional independence at 6 months for patients both with and without HAS, irrespective of HAS characteristics.
Conclusions:
- Intravenous alteplase promotes a measurable reduction in the hyperdense artery sign, irrespective of its location or extent.
- Alteplase treatment improves functional independence at six months for ischemic stroke patients, including those presenting with a HAS.
Objective:
To investigate whether the location and extent of the CT hyperdense artery sign (HAS) at presentation affects response to IV alteplase in the randomized controlled Third International Stroke Trial (IST-3).
Methods:
All prerandomization and follow-up (24-48 hours) CT brain scans in IST-3 were assessed for HAS presence, location, and extent by masked raters. We assessed whether HAS grew, persisted, shrank, or disappeared at follow-up, the association with 6-month functional outcome, and effect of alteplase. IST-3 is registered (ISRCTN25765518).
Results:
HAS presence (vs absence) independently predicted poor 6-month outcome (increased Oxford Handicap Scale [OHS]) on adjusted ordinal regression analysis (odds ratio [OR] 0.66, p < 0.001). Outcome was worse in patients with more (vs less) extensive HAS (OR 0.61, p = 0.027) but not in proximal (vs distal) HAS (p = 0.420). Increasing age was associated with more HAS growth at follow-up (OR 1.01, p = 0.013). Treatment with alteplase increased HAS shrinkage/disappearance at follow-up (OR 0.77, p = 0.006). There was no significant difference in HAS shrinkage with alteplase in proximal (vs distal) or more (vs less) extensive HAS (p = 0.516 and p = 0.580, respectively). There was no interaction between presence vs absence of HAS and benefit of alteplase on 6-month OHS (p = 0.167).
Conclusions:
IV alteplase promotes measurable reduction in HAS regardless of HAS location or extent. Alteplase increased independence at 6 months in patients with and without HAS.
Classification Of Evidence:
This study provides Class I evidence that for patients within 6 hours of ischemic stroke with a CT hyperdense artery sign, IV alteplase reduced intra-arterial hyperdense thrombus.
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