The DAShED (Diagnosis of Aortic Syndrome in the ED) study v1.0
Research type
Research Study
Full title
An observational cohort study of people attending the ED with symptoms of Acute Aortic syndrome (AAS)
IRAS ID
315948
Contact name
Rachel McLatchie
Contact email
Sponsor organisation
University of Edinburgh
Duration of Study in the UK
0 years, 5 months, 30 days
Research summary
Research Summary
Acute aortic syndrome (AAS) is a life-threatening emergency condition affecting the aorta (the main blood vessel which makes sure adequate blood is delivered around the body). AAS is a relatively rare condition affecting ~4000 people in the UK every year. Research suggests 38% of these people are not correctly diagnosed in the Emergency Department (ED). With the challenges in reaching a correct diagnosis, several strategies have been identified to rule out the condition of AAS. These strategies include combining clinical probability scoring with blood tests (a biomarker called D-Dimer) to indicate whether computed tomographic angiography (CTA)(a scan of the aorta) is required to diagnose AAS. However, when applying these strategies to a large Emergency Department population, this results in a high rate of CTA's but low numbers of actual cases of AAS. Unrestricted use of CTA's incurs significant costs, has resource implications and leads to potentially avoidable exposure to ionising radiation. Current guidelines reflect the uncertainty of existing evidence on the best approach to ruling in or out AAS.
This study aims to collect data on patients presenting with possible AAS, to begin to evaluate the effectiveness of different diagnostic strategies, and how they impact the clinicians decisions to use CTA scans. This will enable us to inform future research and guidelines.
We plan to recruit all patients attending ED with possible AAS in at least 5 EDs over a 4-week period, collecting data at the time of their attendance to the ED (prospectively), or if any data is missed we will retrospectively collect that data. Consent to collect this data is not required. Endpoint measures will be describing the characteristics of patients presenting with possible AAS.
Summary of Results
Our study has illustrated the current real-world management of Acute Aortic Syndrome (AAS) in the Emergency Department (ED), the difficulty facing ED clinicians in making a diagnosis of AAS, and the limitations of methods for selecting patients for CT angiogram aorta (CTA). 5548 patients were included in the study. 14 patients had a confirmed AAS with a mortality of 42%. Average time from ED attendance to confirmed AAS was 6 hours, with 4 patients with AAS, having a delay to diagnosis of over 24 hours. 1 in 100 patients in whom the ED clinician thought AAS was possible, had AAS. 1 in 1660 patients in whom the ED clinician considered AAS not possible, had AAS. 1 in 29 patients in whom the ED clinician thought AAS the most likely diagnosis, had AAS. 99.7% of patients presenting with potential AAS symptoms did not have AAS but 1 in 10 patients underwent CT, with 1 in 42 CT scans confirming AAS. The best clinical decision tool to facilitate decision to CTA and to outperform ED clinician gestalt is not yet clear. More research is required in truly undifferentiated ED populations such as these.
REC name
South Central - Oxford C Research Ethics Committee
REC reference
22/SC/0219
Date of REC Opinion
4 Jul 2022
REC opinion
Favourable Opinion