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Research suggests thrombolysis is effective for acute ischaemic stroke

BMJ 2005; 330 doi: https://doi.org/10.1136/bmj.330.7501.1167-a (Published 19 May 2005) Cite this as: BMJ 2005;330:1167
  1. Barbara Kermode-Scott
  1. Calgary

    New Canadian research suggests that thrombolysis is a safe and effective treatment for acute ischaemic stroke (CMAJ 2005;172: 1307-12).

    Researchers assessed the safety and effectiveness of tissue plasminogen activator (alteplase, t-PA) as a routine treatment for acute stroke at 60 centres across Canada.

    In Canada, alteplase treatment for stroke was conditionally licensed in 1999. As a condition of approval, a prospective registry to monitor safety was mandated by the federal government. The Canadian alteplase for stroke effectiveness study (CASES) was launched to collect data on outcomes for all patients treated with alteplase in Canada.


    Embedded Image

    An occupational therapist helps a stroke patient improve his coordination. More than a third of patients in the trial returned to a pre-stroke level of functioning

    Credit: AJP PHOTO/SPL

    The 2.5 year study involved 1135 stroke patients at 27 tertiary care hospitals (10 high volume centres) and 33 community hospitals. Patients were given alteplase intravenously at a dosage of 0.9 mg/kg body weight. The severity of stroke was high (with a median score of 14 (interquartile range 9-19) on the National Institutes of Health stroke scale). The median age of the patients was 73 (63-80) years. Slightly more men than women were treated. A large majority of patients were white. The median time from onset of stroke to treatment was 155 (130-175) minutes.

    Researchers at the University of Calgary's stroke programme analysed the data from CASES and concluded that 36.8% of people treated with alteplase had an excellent clinical outcome (a return to a pre-stroke level of functioning, modified Rankin scale score 0-1). Symptomatic intracranial haemorrhage occurred in 4.6% of the patients (95% confidence interval 3.4% to 6.0%); 75% of these patients died in hospital. An additional 1.3% (0.7% to 2.2%) of patients had hemiorolingual angio-oedema.

    The national prospective cohort study found no differences in the rates of excellent outcome or symptomatic intracranial haemorrhage between the high volume and low volume centres or between the tertiary care hospitals and the community hospitals.

    “This study was a Canadian effort to show that t-PA was effective, safe and could be used in all kinds of communities all across the country,” said stroke neurologist Dr Michael Hill, one of the authors of CASES. “These findings are extremely important because we now have definitive evidence that widespread use of t-PA for severe stroke will save lives and help many people return to a completely normal life.”

    To deliver thrombolysis to people with acute ischaemic stroke the appropriate infrastructure and appropriately trained doctors are needed, pointed out Dr Hill. “You need to have people with expertise in stroke medicine who are able to be on hand to make judgments about who should and who should not receive t-PA for stroke. That training has not been emphasised in the past. It's something that we have to start doing.”

    The design, management, data collection, and analysis of the study were funded by a partnership between the Canadian Stroke Consortium, the Canadian Stroke Network, and the Heart and Stroke Foundation of Canada. The study was partly sponsored by Hoffmann-La Roche Canada, which commissioned the study, helped with infrastructure and paid investigators an honorarium of $100 per patient (£54; €79).

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