New imaging guidelines for clinicians, radiologists diagnosing acute aortic syndrome

The Canadian Medical Association Journal has released new guidelines to help clinicians, including radiologists, spot a difficult-to-diagnose aortic ailment.

Acute aortic syndrome is a life-threatening condition that is misdiagnosed in up to 38% of visits. And a patient’s risk of death can jump by 2% for each hour of delay in diagnosis.

Traditionally, those with suspected AAS are evaluated with electrocardiogram-gated contrast-enhanced computed tomography. However, authors of the updated recommendations say this is “inefficient,” leading to unnecessary downstream healthcare costs and an uptick in contrast-associated complications, among other downsides.

Robert Ohle, an emergency physician at the Health Science North Research Institute, in Sudbury, Ontario, and colleagues say the July 20 update draws from past American Heart Association and European Society of Cardiology suggestions.

The new recommendations are summarized below.

Assess risk factors, pain features and high-risk physical exam findings for a solid pre-test profile.

Connective tissue disease, aortic valve disease, recent aortic procedure, aortic aneurysm and family history of AAS are all high-risk traits. Concerning pain includes sudden-onset or thunderclap pain, severe or worst-ever pain, tearing, migrating or radiating pain. Finally, clinicians should key in on aortic regurgitation, pulse deficit, neurological deficit and hypotension/pericardial effusion.

Those without the above risk factors should not undergo further testing.

Patients at moderate risk for AAS can undergo D-dimer testing. High-risk individuals should receive immediate electrocardiogram-gated CT of the aorta.

Ohle and colleagues also included a clinical decision aid in the guidelines, and maintained the guidance is not meant to be a one-size-fits-all approach. 

"This document may serve as a basis for adaption by local, regional or national guideline groups," they wrote. "For example, guideline implementation in an urban center with 24-hour access to CT may differ from a rural or remote location that requires transfer of a patient with accompanying staff."

Read the guidelines in greater detail here.