Diagnosing acute aortic dissection remains one of the most difficult challenges in emergency medicine. Symptoms can overlap with many more familiar diagnoses, and no simple blood test can yet reliably identify every patient who needs urgent imaging.
That challenge was central to Approaches to Diagnosing Acute Aortic Dissection in the ED, a national education meeting organised by the Aortic Dissection Charitable Trust in partnership with the Royal College of Emergency Medicine (RCEM).
Emergency physicians, radiologists, researchers, patient safety specialists and people with lived experience of aortic dissection took part in the meeting. Drawing on clinical cases and the updated RCEM guidance, speakers discussed how emergency teams decide which patients need an urgent scan.
RCEM guidance on diagnosing thoracic aortic dissection in the Emergency Department has now been updated to reflect the growing evidence base that includes research, education and collaboration that the Aortic Dissection Charitable Trust has helped fund, support and bring into national discussion.
Opening the event, Catherine Fowler, Trustee of the Aortic Dissection Charitable Trust, reflected on this, on how far the charity’s work on diagnosis and service change has progressed. What began with patients and families calling for greater recognition of aortic dissection has grown into sustained work with clinicians, researchers, and professional organisations to improve how AD is recognised and investigated, turning patient advocacy into practical change in emergency departments.
Aortic Dissection Can Be Difficult to Recognise
Aortic dissection can present in many ways. The classic description of sudden severe chest pain radiating to the back is important, but it does not describe every patient. People may present with back or abdominal pain, collapse, neurological symptoms, limb problems or other features that initially suggest a different condition.
Professor Matt Reed, Consultant in Emergency Medicine in Edinburgh, used real clinical cases to demonstrate how easily that can happen. In one case, a patient presented with what appeared to be acute loss of blood supply to an arm. The immediate diagnosis seemed convincing, but a post-mortem later showed that the underlying cause had been an acute aortic dissection.
Aortic dissection should remain a consideration when the presentation fits. Abrupt onset of pain was highlighted as particularly important. Severe pain may have improved by the time a patient arrives in hospital, so improvement should not automatically provide reassurance.
But this is where diagnosis becomes difficult as emergency clinicians regularly see chest, back and abdominal pain, and most of those patients will not have an aortic dissection. The challenge is recognising the smaller number whose history or clinical findings mean that further investigation is needed.
Updated RCEM Guidance for Emergency Departments
Dr Catherine Hayhurst, Consultant in Emergency Medicine and Co-Chair for Quality at RCEM, presented the best practice guidance for thoracic aortic dissection, developed with input from the Royal College of Radiologists to provide a shared framework between emergency departments and radiology teams.
At its core is the aim that emergency clinicians should have local pathways that work at 3am as well as 3pm, and that those pathways support clinicians when aortic dissection remains a realistic possibility. Dr Hayhurst explained that where a patient has a compatible presentation, no firm alternative diagnosis and recognised high-risk features, CT angiography should be considered. The guidance draws on features included in the Aortic Dissection Detection Risk Score (ADD-RS), while recognising that clinical judgement remains essential.
The updated guidance represents an important development in a much wider programme of work. Research supported by the Aortic Dissection Charitable Trust has helped build the evidence around clinical decision-making, diagnostic pathways and new approaches to identifying acute aortic syndrome. Bringing that evidence together with RCEM allows research to move closer to everyday clinical practice.
Knowing What to Do Next
Several speakers returned to the same issue during the day, recognising aortic dissection is only the beginning.
Professor Steve Goodacre explained that although CT angiography remains the definitive investigation, scanning every patient would place enormous pressure on radiology services and expose many people to unnecessary imaging. He emphasised that the ADD-RS score can help clinicians structure their assessment, but there is not yet enough evidence to hand the entire diagnostic decision over to this algorithm.
Sometimes the most important question is what else could this be?
Using D-Dimer Carefully
Dr Sarah Wilson, Consultant in Emergency Medicine at Frimley Park Hospital, looked at the role of D-dimer in suspected acute aortic syndrome. Her discussion made clear that D-dimer should not be treated as a general screening test for aortic dissection. Its usefulness depends on the clinical context and the patient’s risk level.
A key practical point was that clinicians should know what they intend to do with the result before requesting the test. If a patient will need CT angiography regardless of the D-dimer result, waiting for the blood test may simply add delay.
For selected patients at lower or intermediate risk however, D-dimer may contribute useful information alongside clinical assessment and risk features. Sarah also discussed the limitations of testing later after symptom onset, when a negative result may provide false reassurance.
Diagnosis is a Team Effort
Dr Austin Smithies, Consultant in Emergency Medicine in Hull, looked beyond the actions of individual clinicians after serious cases of missed aortic dissection, and examined how the whole diagnostic system worked.
He described the diagnosis as a “team sport”. A patient may be seen by ambulance clinicians, triage nurses, junior doctors, senior emergency physicians, radiologists and specialists. Each point of contact offers another opportunity to notice something important, so good communication matters.
Austin described how his team encouraged a culture where staff felt able to question and challenge an initial diagnosis. This initiative, in collaboration with TADCT, went on to win the 2023 Health Services Journal Patient Safety Award.
Could Point-of-Care Ultrasound Help?
Dr Luke Flower, Specialty Registrar in Intensive Care Medicine, discussed the potential role of point-of-care ultrasound (POCUS) in helping clinicians identify important abnormalities or decide that definitive imaging is needed urgently. POCUS is quick, repeatable and can be performed without moving a critically unwell patient to another part of the hospital. It does not replace CT angiography, but it may help identify red flags, help rule in AD and guide the next stage of investigation.
As with many parts of diagnosis, training and appropriate use are essential. The value lies in adding another piece of information to the clinical picture rather than expecting one investigation to provide every answer.
Looking for the Next Diagnostic Tools
Research may eventually provide clinicians with options that do not currently exist. Dr Tien Zhao, Clinical Lecturer in Cardiovascular Medicine at the University of Cambridge, discussed the search for new biomarkers that could identify damage to the aorta through a blood test. Previous candidates have shown promise but have struggled with problems such as timing, specificity, laboratory practicality or the ability to distinguish dissection from other serious conditions. But his team is now investigating cell-free DNA and whether patterns released following aortic injury could provide a more specific signal.
Artificial Intelligence and the Diagnostic Challenge
Dr Jim Zhong, Interventional Radiologist at Leeds Teaching Hospitals NHS Trust, explored another area supported by the charity, the AORTA-AI project looked at whether machine learning could help identify patients with acute aortic syndrome.
Emergency departments collect large amounts of information, and AI may eventually help clinicians recognise combinations of features that indicate increased risk. However, aortic dissection creates a difficult problem for artificial intelligence because it is rare. A model can appear highly accurate simply because almost everyone being assessed does not have the condition.
The challenge is creating something sensitive enough to identify genuine cases without generating an unmanageable number of false positives. AI may become part of that pathway in the future, but it needs careful evaluation before it can safely support clinical decisions.
Research Moving into Clinical Practice
For the charity, one of the most encouraging aspects of the meeting was seeing different parts of our work coming together.
The charity has funded and supported research into diagnostic decision-making, biomarkers and artificial intelligence. We have brought patients and families into professional education, supported national discussions around diagnosis and worked with clinicians to develop better pathways within their hospitals. The updated RCEM guidance shows how the evidence base is beginning to influence practice.
Research alone does not improve outcomes. It needs to reach the clinicians making difficult decisions in emergency departments, and it needs to be translated into guidance and systems that can work during a busy overnight shift as well as during a specialist teaching session.
Building Safer Emergency Pathways
Emergency departments work under significant pressure, and diagnostic decisions must balance the danger of missing a life-threatening condition with the consequences of unnecessary investigation, so the system around those decisions can improve.
Clinicians can be supported by clearer guidance. Teams can create local pathways. Senior review can be available when uncertainty remains. Nurses and other professionals can be encouraged to escalate concerns. Research can improve risk assessment, while new biomarkers and technologies may eventually give clinicians better diagnostic tools.
Most importantly, aortic dissection should remain a consideration when the patient’s presentation fits, even when another explanation initially appears more likely.
By continuing to bring together emergency clinicians, researchers and people with lived experience, the Aortic Dissection Charitable Trust will keep supporting the education and practical changes needed to improve diagnosis.
Earlier recognition gives patients the best opportunity to reach specialist treatment in time. Improving that emergency pathway remains one of the charity’s most important priorities.
