Serial Alberta Stroke Program Early Computed Tomography Score From Baseline to 24 Hours in SWIFT
A Novel Surrogate End Point for Revascularization in Acute Stroke
See related article, p 723.
Liebeskind et al1 aimed to establish serial Alberta Stroke Program Early Computed Tomography Score (ASPECTS) as a novel measure of ischemic evolution and of the potential therapeutic effects of reperfusion. They conclude that the 24-hour ASPECTS is better at prediction of 90-day function than a baseline score and infer that it provides an early surrogate end point for thrombectomy trials. Good prediction could be valuable. It may render research more practical and could be a factor in training interventionalists on patient selection through feedback on outcomes.
Their findings need to be interpreted with caution, however, for reasons of patient selection, potential confounding, statistical issues, exclusion of alternatives, and timing of data collection.
This is a retrospective study on a subset of patients for whom complete data were available. It is unsurprising that the 24-hour scan appearance associates more strongly with outcome than a baseline scan; although their patients had not been explicitly selected to have near-normal imaging, the exclusion of patients with visible large infarcts certainly skewed the sample toward uniformly high ASPECTS at baseline. Clinical measures, such as …