Aortic Dissection Detection Risk Score With D-dimer to Rule-Out Acute Aortic Syndrome

Inclusion Criteria: * Adult patients aged ≥ 18 years; AND * Presentation to the ED with any of the following symptoms: acute onset (\<14 days) chest pain, abdominal pain, back pain, syncope, or signs of malperfusion (e.g. limb ischemia, neurological deficit); AND * AAS is considered as a possible differential diagnosis by the treating physician. Enrolment in the study will be determined by the attending physician during initial medical consultation in the ED and prior to establishing a final diagnosis. Exclusion Criteria: * An alternative diagnosis to AAS established by the treating physician after the initial assessment; OR * Trauma cases; OR * Patients with a known diagnosis of AAS before the index ED visit (e.g. with a diagnostic imaging done before the ED visit or referral from other institutions for AAS); OR * Clinical severity or other conditions not allowing complete evaluation/proper enrolment; OR * Patient who refuse to participate.