A prognostic score combining age and stroke severity showed that the oldest, most severe patients gained the most benefit from EVT.
Patients who are older and who have had severe acute ischemic strokes appear to benefit more from endovascular therapy (EVT) than younger patients with less severe strokes, according to a study of a new prognostic score.
In a paper published online June 18, 2018, in Stroke, researchers led by Raphael Le Bouc, MD (Sorbonne Universite, Paris, France), say the results strongly suggest that patients should not be denied treatment with EVT based on age or stroke severity.
Le Bouc and colleagues developed an easy-to-calculate and “instantaneous” prognostic score based on patient age and stroke severity. Data were taken from 4,079 patients with acute ischemic stroke from the Paris Stroke Consortium registry, with all assigned a stroke checkerboard score. Patients received 1 point per decade if they were aged 50 or older, and 2 points for every 5 points on the National Institutes of Health Stroke Scale (NIHSS). The primary endpoint was adjusted common odds ratio (OR) for an improvement in modified Rankin Scale (mRS) at 90 days postprocedure in patients classified as having low, intermediate, or high stroke checkerboard scores.
In patients who did not undergo EVT, a checkerboard score of less than 8 predicted good outcome, with 82% of such patients having mRS 0-2. However, checkerboard scores greater than 12 predicted poor outcomes, with 77% of these patients having mRS 4-6.
Conversely, in patients who underwent EVT, the procedure was associated with better outcomes in patients with high and intermediate checkerboard scores, and poor outcomes in those with low scores.
The researchers cautioned that these results are observational and “should not be misinterpreted as arguing that EVT may not be justified from now on in younger patients with less severe deficit.”
Instead, Le Bouc and colleagues say, “they prove the need for randomized clinical trials to determine the value of EVT in those patients.”
To rule out the effect of possible selection bias, the researchers also conducted a case-control analysis in a sub-sample of 449 patients who would have qualified for EVT based on current guidelines.
In this case-control analysis, EVT was again associated with better outcomes in patients with high and intermediate checkerboard scores, and no benefit in patients with low scores.
“Thus, the different response to EVT observed in the three [stroke checkerboard] groups is unlikely to be related to confounding factors that would affect simultaneously treatment choice and clinical outcome,” the researchers write.
In their discussion of the results, they also note that age and NIHSS score are important determinants of stroke outcome, but the combination “has seldom been investigated.”
“Although other clinical factors, such as treatment delay or premorbid status, could add significant prognostic information, the kind of strategy presented with the [stroke checkerboard] score may be helpful for the decision to perform EVT in specific groups of patients, particularly older patients with severe strokes,” Le Bouc and colleagues conclude.
Sources:
Le Bouc R, Clarencon F, Meseguer E, et al. Efficacy of endovascular therapy in acute ischemic stroke depends on age and clinical severity. Stroke. 2018;Epub ahead of print.
Disclosures:
Le Bouc reports no relevant conflicts of interest.
