Disappearing hyperdense middle cerebral artery sign in ischaemic stroke patients treated with intravenous thrombolysis: clinical course and prognostic significance
- T Kharitonova1,
- M Thorén1,
- N Ahmed1,
- J M Wardlaw2,
- R von Kummer3,
- L Thomassen4,
- N Wahlgren1,
- for the SITS investigators
- 1Department of Neurology, Karolinska University Hospital, Stockholm, Sweden
- 2Division of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK
- 3Department of Neuroradiology, University Hospital, University of Technology, Dresden, Germany
- 4Department of Neurology, Haukeland University Hospital, Bergen, Norway
- Dr T Kharitonova, SITS International Coordination Office, Karolinska Stroke Research Unit, Department of Neurology, Karolinska University Hospital- Solna, SE-171 76 Stockholm, Sweden; tatiana.kharitonova{at}ki.se
- Received 25 March 2008
- Revised 6 July 2008
- Accepted 16 July 2008
- Published Online First 17 October 2008
Abstract
Background and purpose: Hyperdense middle cerebral artery sign (HMCAS) on CT is a well known indication of thromboembolic arterial occlusion. Its disappearance after thrombolytic therapy is poorly described. Taking the rate of HMCAS disappearance as a surrogate for MCA recanalisation, its prognostic value after intravenous thrombolysis was examined.
Methods: 1905 stroke patients with HMCAS on admission CT scan in the Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Register (SITS-ISTR) were studied. On follow-up CT scans 22–36 h after thrombolysis, HMCAS disappeared in 831 cases, persisted in 788 and was uncertain in 122; follow-up CT was not done in 164 cases.
Results: Patients whose HMCAS disappeared were younger (median age 67 years vs 69 years for persistent; p = 0.03), with milder stroke (admission National Institute of Health Stroke Scale (NIHSS) score was 16 vs 17; p<0.005) and were less likely to have early infarct signs on admission CT (26% vs 33%; p<0.005). Patients with disappearing HMCAS were more likely to have early improvement in NIHSS score (median improvement 2 vs 0 at 2 h; 4 vs 1 at 24 h), be independent at 3 months (42% vs 19%), with fewer deaths (15% vs 30%) than those with persistent HMCAS. In multivariate analysis, HMCAS disappearance independently predicted functional independence and survival. Early NIHSS improvement independently predicted HMCAS disappearance.
Conclusions: HMCAS disappeared after intravenous thrombolysis in about half of cases and these patients had twice as good outcomes compared with those with persistent HMCAS. The prognosis in patients with MCA occlusion that persists after intravenous thrombolysis is poor, which may indicate the need for an alternative treatment approach to this subgroup.
Footnotes
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Competing interests: NA is an employee of SITS International. SITS International receives an unrestricted grant from Boehringer-Ingelheim. RvK has received honoraria for lectures and/or for advisory boards from Boehringer-Ingelheim, Sanofi-Aventis, Astra-Zeneca, Bayer, Pfizer, NovoNordisk, Astellas, Terumo, Paion and Novartis. JMW works for the University of Edinburgh and provided imaging expertise for the SITS-MOST registry, including design of the image data acquisition and reading of scans submitted to SITS-MOST for expert review. She has received honoraria only for providing expert scan interpretation for SITS-MOST from SITS International who are supported by Boehringer-Ingelheim. LT has received honoraria for lectures and financial support for research nurses from Boehringer-Ingelheim. NW is chairman of SITS International. SITS International receives an unrestricted grant from Boehringer-Ingelheim. NW has received honoraria for lectures and/or for advisory boards from Boehringer-Ingelheim, Sanofi-Aventis, Astra-Zeneca, Bayer and Thrombogenics.
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Funding: SITS-ISTR is funded by an unrestricted grant from Boehringer-Ingelheim (BI), and by a grant from the European Union Public Health Authority (PHEA). Preparation of this paper was independent of the funding organisation. The views expressed are those of the authors. Uppsala Clinical Research (UCR), Sweden, develops, maintains and upgrades the software for SITS register in close collaboration with SITS.
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Ethics approval: Ethics approval was provided in each participating country in accordance with national legislation.
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See Editorial Commentary, p 248
