SOAR Study: Southern Outcomes in Aortic Rule-Out (ADvISED External Validation Study)

Area of Science:

• Cardiology
• Radiology
• Emergency Medicine

Background:

• Acute aortic syndromes (AAS) are life-threatening but uncommon causes of chest pain.
• Computed tomography angiography (CTA) is sensitive for AAS but overutilized, leading to risks and costs.
• The ADvISED algorithm (ADD-RS + D-dimer) shows promise for ruling out AAS but needs external validation.

Purpose of the Study:

• To externally validate the ADvISED rule-out algorithm in a real-world emergency department setting.
• To assess the algorithm's negative predictive value (NPV) and failure rate for diagnosing AAS.
• To determine if the algorithm can safely reduce unnecessary CTA utilization.

Main Methods:

• Retrospective cohort study of 1000 adult patients undergoing CTA for suspected AAS.
• Calculated Aortic Dissection Detection Risk Score (ADD-RS) and extracted D-dimer levels.
• Assessed the NPV and failure rate of the ADvISED algorithm (low ADD-RS [0-1] + D-dimer < 500 ng/mL).

Main Results:

• Forty-one patients (4.1%) were diagnosed with AAS.
• In 180 low-risk patients (low ADD-RS, negative D-dimer), one AAS (IMH) was found, yielding an NPV of 99.4%.
• The algorithm's failure rate was 0.6%, with no Stanford type A AAS missed.

Conclusions:

• The ADvISED rule-out algorithm demonstrated excellent NPV and safety in this external validation cohort.
• The algorithm can serve as a clinical decision aid to reduce unnecessary CTA in low-risk patients.
• Prospective studies are recommended to evaluate its impact on imaging stewardship and patient outcomes.