Abstract T P9: Predictive Value of NIHSS for the Hyperdense Artery Sign
Background: Anecdotally, many use a total NIHSS value to determine need for endovascular involvement in acute ischemic stroke patients. However, no NIHSS value has been shown to be predictive of artery occlusion. We aim to identify an NIHSS threshold that predicts vessel occlusion as measured by hyperdense artery sign
Methods: The UCSD SPOTRIAS prospectively collected database was analyzed for patients diagnosed with acute ischemic stroke (AIS) who received a noncontrast CT on initial evaluation. Groups with and without hyperdense artery sign were compared via Wilcoxon-rank sum and Fisher’s Exact Test. ROC analysis was conducted to determine AUC and threshold NIHSS to predict artery occlusion. Sensitivity and Specificity, and positive and negative predictive value were calculated.
Results: Of 1617 acute ischemic stroke patients, hyperdense artery sign was present in 204 (12.6%). The hyperdense artery group had more women (52.9% vs 44%, p=0.02), higher rate of atrial fibrillation (38.2% vs 22.2%, p<0.0001), and lower rate of prior cerebrovascular disease (23.1% vs 31.7%, p=0.016). Mean NIHSS was 17.7 in those with hyperdense artery, compared with 9 in those without (p<0.0001). In ROC analysis, the best NIHSS threshold to predict hyperdense artery was 12.5 with AUC of 77.73% (95% CI 74.57, 80.89), sensitivity of 72.5%, and specificity of 73.7%. Positive Predictive Value was 28.5; Negative Predictive Value was 94.9.
Conclusions: In our AIS population, a NIHSS cutoff of 12.5 was most predictive of artery occlusion, as measured by hyperdense artery sign. The AUC was only moderate and the PPV low at 28.5%. The NPV, however was high, which indicates that patients with NIHSS less than 12-13 are very unlikely to show hyperdense artery signs. This may guide the decision to consider the need for further vessel imaging and endovascular therapies.
Author Disclosures: A.K. Guzik: None. R. Raman: None. K. Ernstrom: None. D.M. Meyer: None. K.S. Rapp: None. B.C. Meyer: None. T.M. Hemmen: None.
- © 2014 by American Heart Association, Inc.