Written by Alex Chen, MD
The combination of a negative D-Dimer (<500 ng/ml) and an Aortic Dissection Detection (ADD) risk score of ≤1 missed 0.3% of patients with acute aortic syndrome.
Why does this matter?
Acute aortic syndromes (AAS) include aortic dissection, intramural aortic hematoma, penetrating aortic ulcer, and aortic rupture. These conditions occupy a special place in our hearts and make us wake up in a cold sweat long after a busy shift. The AAS are both rare and difficult to diagnose, leading to a significant amount of over-testing. The authors of this article cite that 2.7% of CTA exams performed in the ED for suspected AAS are actually positive. That’s a pretty poor bang for your buck.
I would like a triple-rule out CT with a sprinkle of D-dimer
This was an international, multi-center, prospective observational study that enrolled 1850 patients. Inclusion criteria were adults presenting acutely (within 14d) with ≥1 of the following: non-traumatic chest pain, abdominal pain, back pain, syncope, or perfusion deficit. Importantly, patients were only enrolled if the provider had AAS in the differential. Overall, there were 3 patients (0.3%) missed utilizing a negative D-dimer plus ADD risk score ≤1 - sensitivity 99.6%, NPV 99.7%. These patients either had a widened mediastinum on CXR or they presented with sudden, severe, ripping chest pain.
A major limitation of this study was the provider-determined enrollment, which was difficult to standardize and potentially introduced bias. Interestingly, they had an incidence of 13% for AAS, which was quite high. This likely means that they selected their population very carefully and adds more validity to these results. Ultimately, this data gives us evidence that a diagnostic algorithm with D-dimer and ADD score could be viable but could paradoxically increase the rate of advanced imaging due to an increased dependence on D-dimer testing. QxMD has a handy calculator for this!
Diagnostic Accuracy of the Aortic Dissection Detection Risk Score Plus D-Dimer for Acute Aortic Syndromes: The ADvISED Prospective Multicenter Study. Circulation. 2017 Oct 13. pii: CIRCULATIONAHA.117.029457. doi: 10.1161/CIRCULATIONAHA.117.029457. [Epub ahead of print]
- REBEL EM has an outstanding, review of this article if you want to dive deeper.
- emDocs has a great general review of acute aortic dissection.
- What's the score? Here is the Aortic Dissection Detection Risk Score.
The scoring system gives 1 point for each column if there is ≥1 risk factor present, for a max score of 3 points.