According to one recent review:
The sensitivty of D-dimer test for AD diagnosis is reported as close to 100% in the literature and has a negative predictive value between 92% and 100% [5, 6]. Two meta-analyses confirmed that D-dimer testing is useful for the diagnosis of suspected acute aortic dissection [2, 3].
Additional references here and here.
D-dimer testing combined with the ADD score might be a useful approach.