I’m sure I sound like a bit of a broken record – yet again covering further attempts by the stroke neurology literature to continue expanding use of tPA for acute stroke beyond its initial, narrowly selected treatment population. This observational, retrospective review from SITS-ISTR would like you to know:
“…this is the first observational study demonstrating that intravenous alteplase therapy within 4.5 to 6 hours of stroke onset for patients compliant with other EU approval criteria resulted in comparable rates of SICH, mortality, and functional independence to treatment initiated within 3 hours. This observation persisted in the multivariate analysis after adjustment for baseline imbalances.”
No difference in outcomes between 0-3h, 3-4.5h, and 4.5-6h – in both guideline-compliant and protocol-violation cohorts, and both adjusted and unadjusted results. The authors, all receiving honoraria or grant support from Boehringer Ingelheim would like you to believe this analysis, also funded by Boehringer Ingelheim, supports a benefit for tPA up to six hours.
…but didn’t we just cover Jeff Saver’s JAMA article that “proved” an obvious time-to-treatment effect, favoring faster treatment?
Which of these observational, retrospective, registry reviews provides us the truth? Is there a time-to-treatment effect that decays benefit with time, or, as this registry suggests, no difference between any time frames?
I suppose it depends on your specific professional conflicts-of-interest.
“Results of Intravenous Thrombolysis Within 4.5 to 6 Hours and Updated Results Within 3 to 4.5 Hours of Onset of Acute Ischemic Stroke Recorded in the Safe Implementation of Treatment in Stroke International Stroke Thrombolysis Register (SITS-ISTR)”
www.ncbi.nlm.nih.gov/pubmed/23689267