Ah, but this is not one of those rants about the inefficacy of tPA. This is just an amuse-bouche of a mention of an article from Stroke, regarding a line of investigation in Asian countries.
In these countries, particularly Korea and Japan, there is some substantial thought given to “low dose” tPA being just as effective, with a lower risk of intracranial hemorrhage. Interestingly, approximately 40% of acute stroke patients in Asian countries is at this lower dose, 0.6 mg/kg compared with the typical 0.9 mg/kg. This study is a retrospective evaluation of registry data from 13 academic stroke centers, comparing 3-month outcomes on the modified Rankin Scale.
There were, essentially, two entertaining bits from this article:
- The rate of symptomatic ICH in centers contributing at least 100 patients during the study period ranges from 3.7% on the low side up to 13.0% on the high.
- Given the constraints of the study, they were unable to demonstrate any reliable difference between the two doses. In fact, as you can see from the figure below, retrospective data can be adjusted, propensity matched, or essentially tortured to show whatever advantage preferred:
Should we be using low-dose? And why stop at 0.6 mg/kg – why not 0.3 mg/kg? And, further down the rabbit hole, back to the ideal dose of … none. Ah, but I kid, I kid ….
“Low-Versus Standard-Dose Alteplase for Ischemic Strokes Within 4.5 Hours: A Comparative Effectiveness and Safety Study”
http://www.ncbi.nlm.nih.gov/pubmed/26243232