A lot of research seems to be focused on using d-dimer as a rule-out strategy for acute aortic dissection. The idea is that a d-dimer <500 (which is what we use for ruling out PE in low-mod risk patients) rules out dissection as well.
A few pearls and pitfalls regarding this:
Studies look very promising, but NO accepted cutoff point (d-dimer) has been defined
This practice has NOT been widely accepted yet
A d-dimer <100 ng/dL rules out aortic dissection with a sensitivity of 100%
A d-dimer of <500 ng/dL rules out aortic dissection with a sensitivity of 98%
Experts in this area seem to be advocating this as a potential rule out strategy
Critics of this approach point out the fact that a subset of patients with dissection (those with intramural hematomas-i.e. no intimal tear) may not release d-dimer into the circulation. But almost all studies include patients with this variant and their d-dimers are almost always elevated.
