How do We Avoid the Aortic Landmines?

March 11, 2024

Written by Chris Thom

Spoon Feed
In this large multicenter observational cohort study, 0.3% of patients presenting with potential acute aortic syndrome (AAS) symptoms ended up having AAS. Clinician gestalt outperformed the available clinical decision rules (CDRs).

Good luck out there…..  
This multicenter study enrolled 5,548 patients with potential AAS symptoms at 27 different emergency departments in the UK. AAS symptoms were considered to be chest, back, or abdominal pain, syncope, or malperfusion symptoms. Clinicians prospectively enrolling patients were asked if AAS was a possible diagnosis and how likely the diagnosis was (on a 1 to 10 scale). Test characteristics of clinical gestalt and several CDRs were assessed, as were CT ordering rate and time to diagnosis. Roughly half of patients were recruited prospectively and half retrospectively by the study team.

14 patients (0.3%) were confirmed to have AAS, which was defined as dissection, intramural hematoma, or penetrating ulcer. However, an additional thirty three patients had alternate aortic pathologies such as ruptured thoracic aneurysms (4) and ruptured abdominal aneurysms (5). A third of patients had a delayed diagnosis of over 24 hours. The AUROC curve for ED clinician likelihood rating was 0.958 (95%CI 0.933 to 0.983), which was higher than any CDR. An Aortic Dissection Detection Risk Score (ADD-RS > 1) with raised D-dimer was 100% sensitive for AAS (95%CI 69% to 100%).

How will this change my practice?
Prior research establishes the importance of timely diagnosis of AAS, with a linear increase in mortality for each hour of delay in diagnosis. AAS remains a challenging diagnosis where one accepts a high negative CTA rate in order to avoid missing atypical or occult cases. This study highlights the importance of clinician gestalt, which was superior to any individual CDR. The combination of clinician gestalt, CDRs, and D-dimer testing deserves further study. Recent literature has also highlighted the role that POCUS (SPEED protocol) can play in adjusting pretest probability and reaching the diagnosis in a timely fashion.

Editor’s note: I question the accuracy of physician gestalt in this study, since they retrospectively included more than half the patients. You can’t assess gestalt well with chart review. You have to ask the physician before labs and imaging. What I take home is that aortic arch pathology is very rare, and (bummer) we have to scan a lot of patients to find the few who have it. ~Clay Smith

Source
Diagnosis of Acute Aortic Syndrome in the Emergency Department (DAShED) study: an observational cohort study of people attending the emergency department with symptoms consistent with acute aortic syndrome. Emerg Med J. 2024;41(3):136-144. Published 2024 Feb 20.