Contribution and Additional Impact of Imaging to the SPAN-100 Score

BACKGROUND AND PURPOSE:Stroke Prognostication by Using Age and NIHSS score (SPAN-100 index) facilitates stroke outcomes. We assessed imaging markers associated with the SPAN-100 index and their additional impact on outcome determination.MATERIALS AND METHODS:Of 273 consecutive patients with acute ischemic stroke (<4.5 hours), 55 were characterized as SPAN-100-positive (age +NIHSS score ≥ 100). A comprehensive imaging review evaluated differences, using the presence of the hyperattenuated vessel sign, ASPECTS, clot burden score, collateral score, CBV, CBF, and MTT. The primary outcome assessed was favorable outcome (mRS ≤ 2). Secondary outcomes included recanalization, lack of neurologic improvement, and hemorrhagic transformation. Uni- and multivariate analyses assessed factors associated with favorable outcome. Area under the curve evaluated predictors of favorable clinical outcome.RESULTS:Compared with the SPAN-100-negative group, the SPAN-100-positive group (55/273; 20%) demonstrated larger CBVs (<0.001), poorer collaterals (P < .001), and increased hemorrhagic transformation rates (56.0% versus 36%, P = .02) despite earlier time to rtPA (P = .03). Favorable outcome was less common among patients with SPAN-100-positive compared with SPAN-100-negative (10.9% versus 42.2%; P < .001). Multivariate regression revealed poorer outcome for SPAN-100-positive (OR = 0.17; 95% CI, 0.06–0.38; P = .001), clot burden score (OR = 1.14; 95% CI, 1.05–1.25; P < .001), and CBV (OR = 0.58; 95% CI, 0.46–0.72; P = .001). The addition of the clot burden score and CBV improved the predictive value of SPAN-100 alone for favorable outcome from 60% to 68% and 74%, respectively.CONCLUSIONS:SPAN-100-positivity predicts a lower likelihood of favorable outcome and increased hemorrhagic transformation. CBV and clot burden score contribute to poorer outcomes among high-risk patients and improve stroke-outcome prediction.

Several scores have been designed to prognosticate clinical outcomes in acute ischemic stroke and assess potential risks of intravenous thrombolysis.¹ Age and stroke severity measured by the National Institutes of Health Stroke Scale are among major independent prognostic factors for determining stroke outcome.^2,3 Stroke Prognostication Using Age and NIHSS (SPAN-100) was conceived by combining age in years and stroke severity measured by the NIHSS⁴ and applying the combination to predict clinical outcome and risk of intracerebral hemorrhage. With individuals older than 80 years of age constituting a significant proportion of hospitalized patients with acute ischemic stroke, the relevance of the SPAN-100 is self-evident.⁵ Moreover, the elderly also have a higher risk of fatality and longer hospitalization, necessitating the consideration of the benefit-harm ratio preceding rtPA therapy. More interestingly, most stroke predictive scores use either clinical or imaging components, and though several exist, their utility in clinical practice is somewhat restricted.¹ Multimodal imaging-selection strategies are evolving into a cornerstone for stroke management to best define target groups with salvageable tissue at risk.^6–9 Apart from excluding hemorrhage and early ischemic changes, the presence and extent of ischemic core, intravascular clot burden, and extent of collaterals are critical elements assessed by imaging, dictating management and outcome in patients with stroke.¹⁰The simplicity of SPAN-100, using readily accessible information including age and NIHSS, makes it attractive for practical use. Furthermore, imaging features accompanying SPAN-100-positivity provide insight into pathophysiologic characteristics of patients evaluated with SPAN-100. We sought to externally validate SPAN-100, document multimodal CT parameters associated with SPAN-100 status, and assess their interaction with SPAN-100 and clinical outcome.