Triaging Large Artery Occlusions

Endovascular intervention for acute stroke can be quite useful – in appropriately selected patients.  However, few centers are capable of such interventions, and the technology to properly angiographically evaluated for large-artery occlusions is not available in all settings.  Thus, it is just as critical for patients to be clinically screened in some fashion to prevent over-utilization of scarce resources.

These authors retrospectively reviewed 1,004 acute stroke patients admitted to their facility since 2008, 328 of which had large-vessel occlusions: ICA, M1, or basilar artery.  They calculated the accuracy, sensitivity, and specificity of multiple different potential clinical scoring systems, cut-offs.  Unfortunately, every score made some trade-off – either in the rate of false-negative results excluding patients from potential intervention, or in the rate of false-positive results serving to simply subject every patient to advanced imaging.  The maximum accuracy of all their various scores topped around around 78%.

The authors’ conclusions are reasonable, if a little limited.  They feel every patient presenting with an acute stroke within 6 hours of symptom onset should undergo vascular imaging.  These are both reasonable, but ignore one of the major uses for simple clinical scoring systems: prehospital triage.  Admitting none of these are perfect, _something_ must be put to use – and, probably, given the current bandwidth for endovascular intervention, something with the highest specificity.

For what it’s worth, we use RACE to triage for CT perfusion, but CPSSS, ROSIER, or just NIHSS cut-offs around 10 would all be fair choices.

“Clinical Scales Do Not Reliably Identify Acute Ischemic Stroke Patients With Large-Artery Occlusion”
https://www.ncbi.nlm.nih.gov/pubmed/27125526