Acute aortic syndrome

Background

• Life-threatening spectrum of acute aortic diseases, including:
  • Aortic dissection
  • Intramural hematoma
  • Penetrating atherosclerotic ulcer

Epidemiology

• Incidence of about 3 per 100,000 people
• About 25% go undiagnosed for more than 24 hours after ED presentation

Clinical Presentation

Complications and Prognosis

• Mortality is proportional to delay in diagnosis, about 2% per hour

Diagnosis

• Mainly made by ECG-gated contrast-enhanced CT of the aorta
• Current recommended approach1 is to clinically risk stratify (see Pretest Probability, below)
  • For low risk, no further investigations are needed; for intermediate risk, use D-dimer to exclude AAS; for high risk, or for intermediate risk with elevated D dimer, proceed to ECG-gated CT aorta

Pretest Probability

Feature	Criterion	Score
Risk factors	No risk factors	0
	Any nonaneurysmal risk factors, including connective tissue diseases, aortic valve disease, recent aortic manipulation, or family history of AAS	1
	Aortic aneurysm	2
High-risk pain features	No high-risk pain features	0
	1 or 2 high-risk pain features, including severe or worst ever, thunderclap or abrupt, tearing or ripping, or migrating or radiating	1
	3 or more of the above high-risk pain features	2
Physical examination findings	No high-risk physical exam findings	0
	Any high-risk physical examination finding, including pulse deficit, neurologic deficit, aortic insufficiency, or hypotension with SBP <90 or pericardial effusion	2
Alternative diagnosis	Suspicion for an alternative diagnosis	-1
	Unsure	0
	AAS is the most likely diagnosis	1

• Interpretation:
  • 0: low-risk (<0.5%); no further investigations
  • 1: moderate-risk probability (0.5 to 5%): D-dimer to further stratify
  • ≥2: high-risk probability (>5%): ECG-gated CT aorta