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Three Part Question

In [adult patients with suspected thoracic aortic dissection] what is the [diagnostic utility of clinical assessment] in [stratifying risk of aortic dissection at the bedside]?

Clinical Scenario

A 72 year old man with a history of hypertension presents to the emergency department with acute onset of sharp chest pain. There are no acute ischemic ECG changes. Thoracic aortic dissection is certainly one of many diagnoses in the differential. You wonder if there is a clinical risk score than can be calculated to categorize the risk of having an aortic dissection.

Search Strategy

Ovid MEDLINE(R) 1946 to November Week 2 2013: [(exp aneurysm, dissecting OR exp aortic aneurysm, thoracic) AND (exp risk assessment OR risk assessment.mp OR risk stratification.mp OR exp diagnostic techniques, cardiovascular) AND (sensitivity.mp. or sensitivity and specificity) OR (‘aortic dissection detection risk score’.mp.)]. Limit to human AND English language and Limit to Publication year 2013.

The Cochrane Library Issue 11 of 12, November 2013: MeSH descriptor: [Aneurysm, Dissecting] explode all trees OR MeSH descriptor: [Aortic Aneurysm, Thoracic] explode all trees AND MeSH descriptor: [Risk Assessment] explode all trees 9 records 0 relevant.

Search Outcome

In all, 393 papers were identified of which two addressed the clinical question. These papers are shown in the table.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Rogers et al, 2011, USA	2538 patients with thoracic aortic dissection enrolled in the International Registry of Acute Aortic Dissection from 1996 to 2009. An aortic dissection detection (ADD) risk score (0–3) was derived. It examines three areas (predisposing conditions, pain features, examination features)	Diagnostic cohort	Proportion of patients with known aneurysm with low (0), intermediate (1) and high (2 or 3) ADD scores	4.3% vs 36.5% vs 59.2%	This was a retrospective study of patients with the target diagnosis, the derivation patient set, does not reflect the patients on whom the test may be applied. Patients with unrecognised aortic dissection were not included in the study. Specificity of the risk tool not studied
Armstrong et al, 1998, USA	74 Patients referred for urgent or emergency evaluation because of signs and symptoms suggesting acute aortic dissection	Case Series	Consistency of presenting features	Symptoms in patients with aortic dissection are highly variable	The diagnosis had already been made or was highly suspected in the patients in this study as determined by testing performed at an outside hospital

Comment(s)

Given the low number of patients who present to the emergency department with a thoracic aortic dissection as well as the variability in presentation, a prospective analysis of the aortic dissection detection risk score would be challenging. It is possible that the specificity could be very low, possibly to the point of being prohibitive.

Clinical Bottom Line

There are no prospectively tested rules to risk stratify chest pain for the risk of dissecting aortic aneurysm. The aortic dissection detection score might be useful but requires prospective validation in an emergency department cohort of patients with chest pain.

References

1. Rogers AM, Hermann LK, Booher AM et al. Sensitivity of the aortic dissection detection risk score, a novel guideline-based tool for identification of acute aortic dissection at initial presentation: results from the international registry. Circulation 2011:123;2213–18.
2. Armstrong WF. Bach DS. Carey LM et al. Clinical and echocardiographic findings in patients with suspected acute aortic dissection. Am Heart J 1998:136;1051–60.