How Development of Blood Biomarkers Could Benefit Prehospital Management of Acute Stroke

Abstract

Stroke is one of the leading causes of death worldwide and leaves most survivors with permanent disability [1,2]. Unfortunately, treatment options of acute stroke are still limited. In developed urban hospitals roughly a third of all ischemic stroke patients receive urgent recanalization therapy, in other words thrombolysis with recombinant tissue plasminogen activator (rtPA) and/or endovascular mechanical thrombectomy for large vessel occlusion (LVO). These treatments are highly efficacious and cost effective, but remain markedly underused [3]. Furthermore, their efficacy is time dependent, with strict therapeutic windows. To enhance the stroke chain of survival, current guidelines recommend a tiered system with acute stroke ready hospitals, primary stroke centers and comprehensive stroke centers to ensure timely initiation of intravenous rtPA with the least possible delay after symptom onset and rapid triage of large vessel occlusions eligible for thrombectomy in a comprehensive stroke center [3].The challenge of stroke diagnostics Time delay in the prehospital phase is the most important reason for missing recanalization therapy. Even for patients meeting the appropriate time window, the median prehospital delay is commonly around 2 h [4]. Emergency medical services (EMS) are challenged with the difficult task of identifying likely acute stroke from the wide range of acutely ill patients and ensuring rapid transport to the appropriate emergency department for immediate neurological examination and diagnostic brain imaging. For now, the main diagnostic groups causing acute strokelike symptoms, namely ischemic stroke, transient ischemic attack, hemorrhagic stroke and conditions mimicking stroke, can only be differentiated with hospital-based tests. EMS are therefore restricted to using simple, nonspecific clinical scales for stroke recognition, preventing them from initiating specific treatments.Mobile CT-equipped ambulances, directed by an onboard stroke neurologist or telemedicine consultation, are one active approach to front load diagnostic and therapeutic procedures and reduce treatment delays [5,6], but require significant resources and are only applicable in urban settings, missing rural areas with longer transportation distances. What is clearly missing is an easier surrogate marker for recognizing the condition of brain tissue (either biochemical or functional) while the described, tiered prehospital stroke management is being advanced. Such markers, including blood troponin measurement and ECG recording, are widely used in the prehospital management of acute myocardial infarction, but are still unavailable for stroke. Useful point-of-care (POC) blood tests would have the significant benefit of being relatively inexpensive and more easily applicable around the world.

Association of Prehospital Oxygen Saturation to Inspired Oxygen Ratio With 1-, 2-, and 7-Day Mortality

“…30 In these situations, the early warning scores and biomarkers serve to standardize decision-making for EMS professionals. 3,31…”

“…30 In these situations, the early warning scores and biomarkers serve to standardize decision-making for EMS professionals. 3,31 In this context, the SpO 2 to FIO 2 ratio provides a simple, continuous, and noninvasive monitoring tool applicable in any clinical situation capable of being handled even by personnel with little training. The SpO 2 to FIO 2 ratio also provides the extra advantage of providing a simple stratification of the patient's risk of clinical deterioration.…”

Optimising Prehospital Pathways to Improve Acute Stroke Reperfusion Therapy Delivery: Systems-Based Approaches

“…The ideal point of care test in the prehospital setting would be able to identify stroke, discriminate between ICH and AIS and within ischemic stroke identify LVO stroke, whilst being portable and easy to use. Several attempts have been made to identify a blood biomarker akin to troponin for myocardial infarction in the context of stroke [101], none have been sensitive or specific enough to allow for use [102]. Glial fibrillary acidic protein (GFAP) at a cut-off of 0.29 ng/ml for example was identified as having sensitivity and specificity of 0.36 and 1.00 for ICH in a prehospital setting [103], thus may have utility in prehospital identification of ICH but will require further validation studies.…”

Update in the Early Management and Reperfusion Strategies of Patients with Acute Ischemic Stroke

“…Parallel with the development of reperfusion therapies, several measures are underway to optimize the prehospital stroke rescue chain. Measures for improvement include continuous public awareness campaigns; education of emergency medical service personnel; the use of standardized, validated scales for recognition of stroke symptoms and for triaging to the appropriate institution; advance notification to the receiving hospital; mobile CT-equipped ambulances directed by an onboard stroke neurologist or telemedicine consultation; and blood biomarkers [ 28 – 30 ]. Prompt assessment and adequate triaging of patients with acute ischemic stroke is crucial for timely delivery of reperfusion therapies and optimize outcome.…”