Blood clot treatment hope for stroke patients
People treated with a blood clot-dissolving drug within three hours of suffering a stroke have a better recovery, with fewer long-lasting or disabling effects, a new study has found.
In a result that underlines the need for a quick response to cases of suspected stroke, an international study published in The Lancet involving more than 67,000 stroke patients found that those who received the drug alteplase had a 75 per cent better outcome if they were treated within the first three hours of a stroke. The benefit rapidly fell, however, if treatment was delayed by even a few hours.
One of the study’s co-authors, Professor Richard Lindley from the University of Sydney, said the study showed that treatment with alteplase significantly increased the odds of a good stroke outcome.
“Alteplase is effective in dissolving blood clots in those who have suffered a stroke, and is particularly effective if it is administered within three hours,” Dr Lindley said.
“Previously, alteplase was deemed ineffective and too risky to treat stroke patients who were elderly, diabetic, or had suffered a severe stroke. Doctors were reluctant to use it and these patients were often excluded from treatment.
“However, this study has found that alteplase is an effective emergency treatment for ischaemic stroke patients (strokes caused by blood clots) and should be available irrespective of age, severity, and clinical presentation.”
Professor Lindley said the study showed that time is crucial in treating stroke patients. The sooner alteplase was administered, the more effective the treatment.
Treatment with alteplase within three hours resulted in a good outcome for 259 (32.9 per cent) of 787 patients who received alteplase, against 176 (23.1 per cent) of 762 patients who received a control medication.
A delay of greater than three hours and up to 4.5 hours resulted in a good outcome for 485 (35.3 per cent) of 1375 patients, compared with 432 (30.1 per cent) of 1437 who received the control medication. And a delay of more than 4.5 hours resulted in a good outcome for 401 (32.6 per cent) of 1229 alteplase patients, versus 357 (30.6 per cent) of 1166 who received the control medication.
“This is an important finding considering how disabling a major stroke is for patients, with health outcomes including paralysis, speech impairment, loss of memory and reasoning ability, and coma,” Professor Lindley said.
“Prompt treatment with alteplase should be considered for all ischaemic stroke patients, as this treatment has the potential to prevent serious disability after stroke.”
The study did find that treatment with alteplase significantly increased the odds of brain haemorrhage, and of fatal brain haemorrhage, within seven days, irrespective of treatment delay, age, or stroke severity. But, overall, it was found that death at 90 days after a stroke was 608 (17.9 per cent) in the alteplase group versus 556 (16.5 per cent) in the control group.
The authors found that, despite an average absolute increased risk of early death from brain haemorrhage of about 2 per cent by about three to six months among alteplase patients, this risk was offset by an average absolute increase in disability-free survival of about 10 per cent for patients treated within three hours and five per cent for patients treated after three hours but before 4.5 hours.
“This treatment is not without its risks. However, the risks are worth the benefits, given that stroke is so disabling,” Professor Lindley said.
Professor Lindley said the study built on earlier research published in The Lancet which found that alteplase was just as effective in older stroke patients as it was in younger patients.
Stroke is Australia’s second biggest killer after coronary heart disease, with one stroke occurring every 10 minutes, and is a leading cause of disability. One in six Australians will have a stroke in their lifetime and 65 per cent of stroke survivors suffer a disability that impedes their ability to carry out daily living activities unassisted.