Background: The HERMES-24 score derived from age and 24-hour National Institute of Health Stroke Scale (NIHSS) has been recently proposed for prognosticating 90-day outcome following large vessel occlusion (LVO) stroke. Excellent predictive performance was achieved in the HERMES, ESCAPE-NA1 and INTERRSect trials cohorts. External validation in routine clinical cohorts is lacking.
Aim: Our study aimed to externally validate and assess the predictive performance of the HERMES-24 score in a large contemporary clinical cohort.
Methods: Patients with confirmed anterior circulation LVO stroke aged >18 years and receiving endovascular thrombectomy (EVT) within 24 hours were included. The association between HERMES-24 score and 90-day functional outcome (mRS ≤2 and ≤3), ordinal mRS and mortality was investigated using generalised linear models. Predictive performance was assessed via the c-statistic.
Results: A total of 1052 patients were included for analysis. Median age and NIHSS at presentation was 75.0 years (IQR 64.0 – 82.3) and 14.0 (IQR 8.0 – 20.0) respectively. TICI 2b or greater reperfusion was achieved in 862 (81.9%). At 90 days, 202 (21.5%) patients had died and 486 (51.8%) regained functional independence (mRS ≤2). The HERMES-24 score demonstrated (similarly to previously) excellent performance for predicting 90-day mRS ≤2 (c-statistic, 0.862, 95% CI: 0.839 – 0.885), mRS ≤3 (c-statistic, 0.870, 95% CI: 0.846 – 0.893), mortality (c-statistic, 0.859, 95% CI: 0.830 – 0.888) and ordinal mRS (c-statistic, 0.808, 95% CI: 0.792 – 0.826).
Conclusion: The HERMES-24 score has utility as a prognostic tool for LVO stroke in the routine clinical setting. Further validation in basilar occlusion LVO stroke would be beneficial.