Neal S. Parikh, MD
Time is brain, and we know it. Yet, stroke systems of care — particularly in the pre-hospital EMS domain — have yet to adapt to the latest and greatest in stroke: endovascular therapy (EVT). For every 8 or so patients treated with endovascular therapy, one patient achieves functional independence despite having suffered an acute, large-vessel occlusion (LVO).1 It behooves us, then, to develop stroke systems of care that deliver patients efficiently and rapidly to centers that provide EVT without compromising care for the remaining patients who would benefit from prompt IV-TPA. Everyone, from the AHA/ASA to endovascular therapy trialists, recognizes this need.
On my count, this is at least the fifth publication in Stroke in 2017 that seeks to meet this need. Others have queried whether the direct-to-mothership model is superior to the drip-and-ship model,2 whether the volume of EVT cases at an individual center impacts outcomes,3 and whether computer modeling can be used to define the catchment area of a hub.4 This all boils down to the key quandary: How should EMS triage and transport patients from the field?
In a recent issue of Stroke, Dr. Nogueira and Dr. Silva provide a well-designed and innovative solution to help answer this question for each individual patient.5 They designed a smartphone application (compatible with Apple and Android systems) that factors in each individual patient’s clinical characteristics to determine the likelihood of IV-tPA and/or EVT and combines this information with real-world traffic data to direct the patient to the most appropriate hospital (primary stroke center for IV-tPA versus comprehensive stroke center where EVT is available).
Of course, there are limitations to an algorithm-driven approach. As the authors admit, the smartphone application’s algorithm “heavily relies” on the likelihood of LVO as determined by the FAST-ED LVO scale. This scale has been validated, and performs similarly to other pre-hospital LVO scales, which is to say that is performs moderately well. Further, the application’s design assumes an ideal world in which local politics and financial considerations are not relevant. Regardless, the development of this application is a great step towards rational design of pre-hospital stroke systems of care. I look forward to seeing further development and testing of this promising concept.
1 Badhiwala JH, Nassiri F, Alhazzani W, Selim MH, Farrokhyar F, Spears J, et al. Endovascular thrombectomy for acute ischemic stroke. A meta-analysis. JAMA Neurology. 2015;314:1832-1843.
2 Milne MS, Holodinsky JK, Hill MD, Nygren A, Qui C, Goyal M. Drip ‘n Ship Versus Mothership for Endovascular Treatment: Modeling the Best Transportation Options for Optimal Outcomes. Stroke. 2017;48:791-794.
3 Rinaldo L, Brinjiki W, Rabinstein AA. Transfer to High-Volume Centers Associated with Reduced Mortality After Endovascular Treatment of Acute Stroke. Stroke. 2017;48:1316-1321.
4 Phan TG, Beare R, Chen J, Clissold B, Ly J, Singhal S, et al. Googling Service Boundaries for Endovascular Clot Retrieval Hub Hospitals in a Metropolitan Setting: Proof-of-Concept Study. Stroke. 2017;48:1353-1361.
5 Nogueira RG, Silva GS, Lima FO, Yeh YC, Fleming C, Branco D, et al. The FAST-ED App: A Smartphone Platform for the Field Triage of Patients With Stroke. Stroke 2017;48:1278-1284.