Pre-Hospital Telestroke vs Paramedic Scores to Accurately Identify Stroke Reperfusion Candidates: A Cluster Randomised Controlled Trial

Abstract

Background:Stroke reperfusion therapy is time critical. Improving pre-hospital diagnostic accuracy including the likelihood of large vessel occlusion can aid with efficient and appropriate diversion decisions to optimise onset-to-treatment time.Objective:To investigate whether pre-hospital telestroke improves diagnostic accuracy when compared with paramedic assessments and to assess feasibility.Methods:We conducted a pragmatic, community-based, cluster randomised controlled trial comparing the diagnostic accuracy of telestroke assessments inside the ambulance to a modified Los Angeles Motor Scale (PASTA score. The primary outcome was the accuracy of predicting reperfusion candidates; secondary outcomes were accuracy, sensitivity, specificity, positive, and negative predictive values of either approach to identify intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) candidates, and true stroke patients by study group. The accuracy of telestroke and PASTA assessments were compared against in-person assessment in the emergency department and to the final diagnosis/intervention for the patient. We also monitored for technical challenges.Results:We recruited 76 patients (35 telestroke; 41 PASTA), between August 2019 and September 2020. Mean age was 72.2 (+/-14.6) years. Telestroke was 100% (95% CI 90-100%) and PASTA 70.7% (54.5-83.9%) accurate in predicting reperfusion candidates compared to pre-imaging emergency department neurologist assessment (p<0.001). When compared to actual reperfusion therapy administered predictive accuracy was 80% (63.1-91.6%) and 60.1% (44.5-75.8%) for telestroke and PASTA respectively (p<0.001). In predicting administration of IVT, telestroke was 80% (63.1-91.6) and PASTA was 56.1 (39.8-71.5) accurate (p <0.001). In predicting intervention with EVT, telestroke was 88.6 (73.3-96.8) and PASTA 56.1 (39.8-71.5) accurate (p=0.005). The service model proved technically feasible and was acceptable to neurologists.Conclusion:Pre-hospital telestroke assessment is feasible, accurate, and superior to the PASTA score in predicting acute reperfusion therapies presenting an effective option to guide pre-hospital diversion decisions.Trial Registration:The trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12619001678189).www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378655&isReview=trueClassification of Evidence:This study provides Class I evidence that intra-ambulance telestroke evaluation has greater diagnostic accuracy compared to the PASTA score performed by paramedics in distinguishing hyperacute stroke patients who are candidates for reperfusion therapy.