Prehospital Triage of Intracranial Hemorrhage and Anterior Large‐Vessel Occlusion Ischemic Stroke: Value of the Rapid Arterial Occlusion Evaluation

Background
The Rapid Arterial oCclusion Evaluation (RACE) score can identify patients with anterior circulation large‐vessel occlusion (aLVO) ischemic stroke for transportation to a comprehensive stroke center for endovascular thrombectomy. However, patients with intracranial hemorrhage (ICH) may also benefit from direct transportation to a comprehensive stroke center for neurosurgical treatment. We aimed to assess if the RACE score can distinguish patients with ICH in addition to aLVO stroke from other patients with suspected stroke.

Methods
We analyzed data from the LPSS (Leiden Prehospital Stroke Study), a multicenter, prospective, observational cohort study in 2 Dutch ambulance regions. Ambulance paramedics documented prehospital observations in all patients aged ≥18 years with suspected stroke. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of a positive RACE score (≥5 points) for a diagnosis of ICH or aLVO stroke, compared with patients with non‐aLVO stroke, transient ischemic attack, or stroke mimic. In addition, we performed a multivariable logistic regression analysis and calculated adjusted odds ratios (ORs).

Results
We included 2004 patients with a stroke code, of whom 149 had an ICH, 153 had an aLVO stroke, 687 had a non‐aLVO stroke, 262 had a transient ischemic attack, and 753 had a stroke mimic. Patients with ICH and aLVO stroke more often had a positive RACE score than other patients with suspected stroke (46.2% and 58.0%, respectively, versus 6.4%; P<0.01). A positive RACE score had a sensitivity of 52.7%, a specificity of 93.6%, a positive predictive value of 55.4%, and a negative predictive value of 92.9% for a diagnosis of ICH or aLVO stroke. In multivariable analysis, a positive RACE score had the strongest association with ICH or aLVO stroke (adjusted OR, 10.11 [95% CI, 6.84–14.93]).

Conclusions
Our study shows that the RACE score can also identify patients with ICH in addition to aLVO stroke. This emphasizes the potential of the RACE score for improving prehospital triage and allocation of patients with stroke.