Using Age-Adjusted D-Dimer vs Traditional D-Dimer to Rule Out Acute Aortic Syndromes

Acute aortic syndromes (AS), including aortic dissection, ulceration, and intramural hematoma, are rare and life-threatening diagnoses. Early diagnosis is critical as mortality increases by 1-2% per hour after symptom onset. D-dimer (DD) < 500 ng/dL, with or without utilization of Aortic Dissection Detection Risk Score (ADD-RS), is a proposed method to rule-out AS in low-risk patients but is not specific. Age-adjusted D-dimer (AADD) has been validated for pulmonary embolism, but has not been studied extensively in AS.

In this study, we investigate the utility of AADD to DD when used to rule-out AS, with and without ADD-RS.

This is a retrospective study of patients presenting the emergency department (ED) from 2012 to 2021 who received a DD and underwent computed tomography angiography (CTA) for Dissection, Coronary Study, or Triple Rule-Out. Sensitivity and specificity for AS was calculated for both DD < 500 ng/dL and AADD. Patients were excluded if they were pregnant, had prior thoracic aortic dissection or repair, presented altered, or younger than 18 years-old.

In total, 5818 unique cases met inclusion criteria. In the DD < 500 ng/dL group sensitivity was 0.979 (0.939-1.000) with a specificity of 0.727 (0.716-0.739). In the AADD group, sensitivity was 0.938 (0.869-1.000, p = 0.16) with a specificity of 0.781 (0.770-0.792, p < 0.05).

AADD appears to have comparable sensitivity, although with a diminished confidence interval, to DD when ruling out AS. Utilization of ADD-RS may help determine which patients are appropriate for screening. Future steps would include a prospective trial on patients presenting to the ED.