A tool that uses early computed tomography (CT) to quantify brain ischemia may effectively predict reperfusion and outcome in patients who suffer acute ischemic strokes, according to a study published online Dec. 12 in Stroke.
Investigators assessed the predictive value of the tool, known as ASPECTS (Alberta Stroke Program Early Computed Tomography Score to Select Patients for Endovascular Treatment) in the Interventional Management of Stroke (IMS)-III Trial. The IMS-III trial compared the effect of tissue plasminogen activator (tPA) alone with a combination of tPA and endovascular therapy on Rankin Scale score.
Using CT data from IMS-III, the ASPECTS researchers, led by Michael D. Hill, MD, of the Hotchkiss Brain Institute at the University of Calgary in Canada, assigned patients an ASPECTS score between 0 and 10. The score quantified the amount of early brain ischemia. They separated 656 patients into ASPECTS of 8 to 10 or 0 to 7 based on baseline CT data.
Participants with scores of 8 to 10 were about twice as likely to have a favorable outcome as those with low scores. However, there was no evidence that ASPECTS interacted with the IMS-III treatments. The results were similar among participants treated with tPA in less than two hours and in cases of internal carotid artery or middle cerebral artery occlusion proven by CT angiography. Higher ASPECTS scores were also associated with a higher probability of recanalization of the primary arterial occlusive lesion (relative risk 1.3) or thrombolysis in cerebral ischemia score 2b/3 reperfusion (relative risk 2.0).
However, their analysis did not determine which specific participants benefited from endovascular therapy after tPA. Nevertheless, the authors argued that “ASPECTS is a strong predictor of outcome and a predictor of reperfusion.”