The PRESTO study: Prehospital triage in patients with suspected stroke

Introduction

In patients with acute ischemic stroke, the blood flow to part of the brain is compromised by a thrombotic occlusion of a cerebral artery. Two effective treatments to recanalize this artery and to restore blood flow of the brain are available in the acute phase of an ischemic stroke: intravenous thrombolysis (IVT) with tissue-type plasminogen activator (alteplase) and endovascular thrombectomy (EVT). In the Netherlands, IVT is available in all hospitals with an emergency department. The subset of patients with ischemic stroke due to an intracranial large vessel occlusion (LVO) can benefit from adjunctive treatment with EVT, a treatment by which an attempt is made to remove the thrombus mechanically. EVT is a specialized treatment and is only available in endovascular-capable centers.
The efficacy of both IVT and EVT strongly declines over time. Therefore, several prehospital stroke scales were developed to identify patients that are likely to have an LVO in the ambulance, which could allow for direct transportation of EVT eligible patients to an endovascular-capable center without delaying IVT for the other patients.

Rationale and aim

The overall aim of the PRESTO study is to improve acute stroke care by a more efficient and effective prehospital selection of patients eligible for endovascular therapy (EVT). We aim to prospectively validate multiple prehospital stroke scales simultaneously to assess their accuracy in predicting LVO in the prehospital setting.

Study design

PRESTO is a prospective multicentre observational cohort study in the southwest of the Netherlands including adult patients with suspected stroke in the ambulance. The paramedic will assess a combination of items from five prehospital stroke scales, without changing the normal workflow. Primary outcome is the clinical diagnosis of an acute ischemic stroke with an intracranial LVO in the anterior circulation. Additional hospital data concerning the diagnosis and provided treatment will be collected by chart review.

Ethics and dissemination

The Institutional Review Board of the Erasmus MC University Medical Centre has reviewed the study protocol and confirmed that the Dutch Medical Research Involving Human Subjects Act (WMO) is not applicable. The best performing scale, or the simplest scale in case of clinical equivalence, will be integrated in a decision model with other clinical characteristics and real-life driving times to improve prehospital triage of suspected stroke patients.

Trial registration number: NTR7595 (www.trialregister.nl)