07 Dec 20. Featured Paper

Hyperdense artery sign, symptomatic infarct swelling & effect of alteplase in acute ischaemic stroke.

Link to paper on Stroke & Vascular Neurology

Authors

Simiao Wu, Grant Mair, Geoff Cohen, Zoe Morris, Anders von Heijne, Nick Bradey, Lesley Cala, Andre Peeters, Andrew J Farrall, Alessandro Adami, Gillian Potter, Ming Liu, Richard I Lindley, Peter A G Sandercock, Joanna M Wardlaw, On behalf of the IST-3 Collaborative Group

Abstract

Background: Alteplase improves functional outcomes of patients with acute ischaemic stroke, but its effects on symptomatic infarct swelling, an adverse complication of stroke & the influence of CT hyperdense artery sign (HAS) are unclear.

This substudy of the Third International Stroke Trial aimed to investigate the association between HAS & symptomatic infarct swelling & effect of intravenous alteplase on this association.

Methods: We included stroke patients whose prerandomisation scan was non-contrast CT.

Raters, masked to clinical information, assessed baseline (prerandomisation) & follow-up (24–48 hours postrandomisation) CT scans for HAS, defined as an intracranial artery appearing denser than contralateral arteries.

Symptomatic infarct swelling was defined as clinically significant neurological deterioration ≤7 days after stroke with radiological evidence of midline shift, effacement of basal cisterns or uncal herniation.

Results: Among 2961 patients, HAS presence at baseline was associated with higher risk of symptomatic infarct swelling (OR 2.21; 95% CI 1.42 to 3.44).

Alteplase increased the risk of swelling (OR 1.69; 95% CI 1.11 to 2.57), with no difference between patients with & those without baseline HAS (p=0.49).

In patients with baseline HAS, alteplase reduced the proportion with HAS at follow-up (OR 0.67; 95% CI 0.50 to 0.91), where HAS disappearance was associated with reduced risk of swelling (OR 0.25, 95% CI 0.14 to 0.47).

Conclusion: Although alteplase was associated with increased risk of symptomatic infarct swelling in patients with or without baseline HAS, it was also associated with accelerated clearance of HAS, which in return reduced swelling, providing further mechanistic insights to underpin the benefits of alteplase.

Keywords

• Acute ischaemic stroke
• Computed tomography (CT)
• Hyperdense artery sign (HAS)
• Infarct swelling
• Third International Stroke Trial (IST-3)