…although the authors of this study draw the opposite conclusion.
In an effort to decrease the administration of TPA to stroke mimics and TIAs, some institutions are moving to the use of CT angiographic and perfusion studies after the initial non-contrast scan. Previous studies have suggested an association between iodinated contrast administration and ICH after TPA.
These authors beg to differ. In their study cohort, they retrospectively evaluate 319 patients receiving TPA for acute stroke, 69 of whom receive contrast and 243 who do not. Depending on whether the ECASS or SITS-MOST definition of symptomatic ICH is used:
ECASS – 4 of 69 (5.8%) with contrast, 12 of 243 (4.9%) without contrast
SITS-MOST: 3 of 69 (4.4%) with contrast, 9 of 243 (3.7%) without contrast
…and that small absolute difference does not reach statistical significance because their numbers are so small. This does not prevent the authors from stating “we found no association of either IV contrast administration or contrast dose with SICH in our series of patients treated with IV rtPA.” They’re not wrong – but they barely address how underpowered their study is, or how every baseline characteristic (age, stroke severity, comorbid conditions) favored their contrast group, yet they still trended towards increased ICH.
Does the author of every TPA article live in a distortion field that blinds them to reasonable consideration of safety issues and study limitations?
“Iodinated Contrast Media and Cerebral Hemorrhage After Intravenous Thrombolysis”
http://stroke.ahajournals.org/content/42/8/2170.short?rss=1