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.

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.

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.

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.