Written by Megan Hilbert
Spoon Feed
Using the aortic dissection detection (ADD) risk score in addition to point-of-care ultrasound (POCUS) and D-dimer, providers can increase their diagnostic accuracy and ensure that the appropriate patients are receiving advanced imaging to make the diagnosis of acute aortic syndrome (AAS).
PROFUNDUS? Wow, that’s deep…
Acute aortic syndromes (AAS) – dissection, intramural hematoma, penetrating ulcer – have high mortality, but low relative incidence. Resource utilization and administration of ionizing radiation are two very important considerations when working in the ED. ED providers must navigate through the minefield of a high-risk differential while not over-testing. It is a tightrope, particularly in patients where aortic pathology is a consideration. This was a prospective management outcome study that evaluated protocol safety, efficiency, feasibility, as well as adherence to this standard protocol. It also evaluated the adjusted safety and efficiency of the modified protocol when adding on age-adjusted D-dimer.
The protocol:
- The ADD is calculated (guideline-compliant clinical score – see MDCalc)
- POCUS (suprasternal and parasternal view) is completed looking for direct signs of aortic pathology (intimal flap, thickening of the wall, outpouching) vs indirect signs (thoracic aortic dilation, pericardial effusion, moderate aortic valve regurgitation).
- D-dimer is collected (age-adjusted interpretation)
Integrated pre-test probability (iPTP) is then calculated (see graphic). Those with low pre-test probability as calculated by the modified protocol could forgo advanced imaging.
Results:
Adding POCUS to the ADD was able to accomplish a 20% net reclassification improvement (24%/-4% for events/non-events, p < 0.001). This resulted in 6% of study participants being reclassified as high-risk by POCUS, with 39% of those having a diagnosis of AAS (wow!). In low-risk patients, the addition of the age-adjusted D-dimer ruled out AAS with 100% sensitivity and 59% specificity (p<0.001). It also was able to rule out 6% more low pre-test probability patients as compared to the standard protocol alone. This corresponded to 2 of 5 less orders for CTA.
How will this change my practice?
This was a well done study that looked to improve our efficiency at diagnosing acute aortic syndromes. With the statistics reported in this paper, I will feel much more confident in not pursuing further advanced imaging if my ultrasound and age-adjusted D-dimer don’t support aortic pathology as the presenting etiology.
Editor’s note: It’s not clear the primary POCUS views studied (parasternal long and suprasternal) were sufficientl. A significant number of patients also had views of the abdominal aorta, apical 4/5 chamber and subcostal 4-chamber. Consider expanding your POCUS to include these as well until more details regarding the POCUS algorithm are available. ~ Nick Zelt
Source
Diagnosis of acute aortic syndromes with ultrasound and d-dimer: the PROFUNDUS study. Eur J Intern Med. 2024 Jun 12:S0953-6205(24)00234-6. doi: 10.1016/j.ejim.2024.05.029. Epub ahead of print. PMID: 38871565.
