A study published early online and in an upcoming edition of The
Lancet found that the stroke drug alteplase is safe and
effective even if administered 1 to 1.5 hours after the conventional
3-hour treatment window. Prof Nils Wahlgren (Karolinska University
Hospital, Stockholm, Sweden) and colleagues also remind that the drug
can still be safely administered within three hours of stroke.
Acute ischemic stroke is a condition characterized by a serious lack of
blood supply to the brain. It is commonly treated with a drug called
alteplase, which dissolves the thrombi (blood clot) that caused the
stroke. Usually alteplase is administered within three hours after
stroke, but Prof Wahlgren and colleagues, in the Safe Implementation of
Treatments in Stroke – International Stroke Thrombolysis Registry
(SITS-ISTR) study, tested the outcomes of patients who received
intravenous alteplase 3 to 4.5 hours after stroke. Of the total sample,
664 patients received the drug 3 to 4.5 hours post-stroke and 11,865
received it within three hours.
The group that received later treatment received alteplase about 55
minutes, on average, later than the group that received earlier
treatment – at 195 vs 140 min. In addition, the later group was about
three years younger and had slightly lower stroke severity than the
within 3 hour group. The results of the study revealed that outcome
measures were similar between the two groups. For example, the
mortality rate for the 3 to 4.5 hour group was 12.7% compared to 12.2%
for the within 3 hours group. The brain hemorrhage rates were 2.2% and
1.6% and the proportions of patients retaining independence were 58.0%
and 56.3%, respectively.
“Our results show that the rates of symptomatic intracerebral
haemorrhage, mortality, and independence at 3 months follow-up in
routine clinical practice are similar between patients for whom
treatment was started between 3 and 4.5 h and for those treated within
3 h after ischaemic stroke onset,” write the authors. “Our findings
lend support to those of the meta-analysis suggesting a potentially
longer timeframe for intravenous [use of alteplase] of 4.5 h.”
Dr Georgios Tsivgoulis and Dr Andrei Alexandrov (Comprehensive Stroke
Center, University of Alabama at Birmingham Hospital, Birmingham,
Alabama USA) write in an accompanying editorial that: “Extension of the
timeframe of systemic thrombolysis seems to be a safe option for
patients with acute stroke…We are looking forward to moving away from
rigid timeframes to treatment based on imaging that can assess brain
pathophysiology and tissue viability.”
Thrombolysis with alteplase 3-4.5 h after acute ischaemic stroke
(SITS-ISTR): an observational study
Nils Wahlgren, Niaz Ahmed, Antoni Dávalos, Werner Hacke,
Mónica Millán, Keith Muir, Risto O Roine, Danilo Toni, Kennedy R Lees,
for the SITS investigators
The Lancet (2008).
DOI:10.1016/S0140-6736(08)61339-2
Click
Here to View Abstract
: Peter M Crosta