Retrospective single‐centre experience on the effect of the DAWN trial on the utilisation pattern, diagnostic yield and accuracy of CT perfusions performed for suspected acute stroke

Abstract

Introduction:The recent DAWN trial created a paradigm shift in acute stroke treatment from 'time-based' criteria (within 6 hours) to 'tissue-based' criteria dependent on advanced neuroimaging such as CT perfusion (CTP). This has expanded the thrombectomy window from 6 to 24 hours and has major implications for healthcare providers involved in acute stroke management. Our aim is to characterise changes in the utilisation, diagnostic yield and accuracy of CTP in the diagnosis of acute stroke in the year following the DAWN trial. Methods: Four hundred and forty-three patients underwent CTP for investigation of suspected stroke between 1 January 2017 and 31 December 2018. Studies in 2017 were considered 'pre-DAWN' while studies in 2018 were considered 'post-DAWN trial'. Electronic medical records were reviewed to extract patient characteristics. Each patient was categorised as early presenter (within 6 hours) or late presenter (over 6 hours). Chi-squared tests were performed to assess for differences in proportions between the 2 years. Results: There was a 50% increase in CTP performed from 177 in 2017 to 266 in 2018. The proportion of all CT that were CTP increased by 40% while CTP in late presenters increased by 70% in 2018. The sensitivity, specificity and proportions of CTP with a final diagnosis of acute stroke, TIA or nonstroke did not demonstrate statistically significant differences between the 2 years. Conclusions: The CTP utilisation, particularly in late presenters, has substantially increased since the DAWN trial. This contributes to increasing burden on healthcare services related to the diagnosis and management of stroke.

Comparing extended versus standard time window for thrombectomy: caseload, patient characteristics, treatment rates and outcomes—a prospective single-centre study

“…In our study, the extension of time window led to a slightly smaller increase in actually treated patients (26.7%) than the 33.3% increase of theoretically EVT eligible patients from a retrospective analysis of a single-centre registry [5]. Our results-in line with previous studies [5][6][7], and [9] comparing pre-and post-DAWN management-show that the main burden of extended time window lies on the clinical and imaging screening of patients (EMS, ER, neurologists and radiologists) rather than their treatment because of the smaller proportion of EVT eligible patients compared with the standard time window. This needs to be taken into account when planning stroke care pathways and resource allocation.…”

“…New AHA [1] and ESO [2] guidelines recommend endovascular treatment (EVT) of large vessel occlusion (LVO) strokes in an extended time window of 6 to 24 h in patients selected with advanced imaging, based on DAWN [3] and DEFUSE 3 [4] trials. However, there are no published data from these trials and only retrospective and speculative data from national registries or single centres [5][6][7][8][9] on the burden of screening these patients, their treatment rates and outcomes as compared with those in the standard time window within 6 h.…”

Early Diagnosis of Acute Ischemic Stroke by Brain Computed Tomography Perfusion Imaging Combined with Head and Neck Computed Tomography Angiography on Deep Learning Algorithm

“…Conventional MRI is effective in displaying acute small infarct and posterior circulation ischemic stroke. At present, the mismatch between PWI and DWI of MRI is a more effective method to judge the ischemic penumbra, but MRI has some limitations, such as long examination time, many contraindications, and high examination cost [ 12 , 13 ]. CT perfusion imaging is a common method to evaluate acute ischemic stroke at present.…”