Aortic Dissection Detection Risk Score

Aortic Dissection Detection Risk Score

Acute aortic dissection may be present in only about one in ten thousand patients presenting to the emergency department. But missing an aortic dissection can be catastrophic. At the same time submitting all patients with suspected dissection to imaging studies may not be feasible in view of the cost and potential risks. Hence a good clinical bedside risk score may be useful, in addition to diligent clinical evaluation.

Aortic Dissection Detection Risk Score (ADD Risk Score) was formulated by IRAD investigators using the International Registry of Acute aortic Dissection. Three groups of high risk features have been evaluated:

1. High risk conditions: Marfan syndrome, family history of aortic disease, known aortic valve disease, recent aortic manipulation and known thoracic aortic aneurysm

2. High risk pain features: Chest, back or abdominal pain described as abrupt in onset, severe in intensity, ripping or tearing.

3. High risk physical findings: Evidence of perfusion deficit in the form of pulse deficit, systolic blood pressure differential, or focal neurological deficit in conjunction with pain; Murmur of aortic regurgitation, which is new or not known to be old, along with pain; Hypotension or shock.

Risk is calculated by the number of categories in which any single risk factor is present. If no high risk features are present, ADD Risk Score is 0. ADD Risk Score is taken as 1 if any single high risk category is present. If two or more risk categories are present, ADD risk score becomes 2 or 3. In ADD Risk Score 2 and 3, immediate imaging and surgical consultation are needed.

In ADD Risk Score 0, imaging is considered if there is unexplained hypotension or mediastinal widening on chest X-ray without any alternative diagnosis. ADD Risk Score 1 is the intermediate risk category in which imaging will be considered if ECG and X-ray chest (as well as history and physical signs) do not suggest an alternate diagnosis. Imaging modality chosen in an unstable patient would be transesophageal echocardiography, though imaging the entire aorta with computed tomography or magnetic resonance imaging would give better yield in stable patients.

Reference

1. Rogers AM, Hermann LK, Booher AM, Nienaber CA, Williams DM, Kazerooni EA, Froehlich JB, O’Gara PT, Montgomery DG, Cooper JV, Harris KM, Hutchison S, Evangelista A, Isselbacher EM, Eagle KA; IRAD Investigators. 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 of acute aortic dissection. Circulation. 2011 May 24;123(20):2213-8.