Calc Function

    • Calcs that help predict probability of a diseaseDiagnosis
    • Subcategory of 'Diagnosis' designed to be very sensitiveRule Out
    • Disease is diagnosed: prognosticate to guide treatmentPrognosis
    • Numerical inputs and outputsFormula
    • Med treatment and moreTreatment
    • Suggested protocolsAlgorithm





    Chief Complaint


    Organ System


    Patent Pending

    Aortic Dissection Detection Risk Score (ADD-RS)

    Rules out aortic dissection.


    ADD-RS + D-dimer (the ADvISED study algorithm) has not been externally validated in ruling out acute aortic dissection and should thus be used with caution. The ADD-RS itself is validated.

    When to Use
    Why Use

    Low to moderate risk patients for whom acute aortic syndromes (AAS) are in the differential diagnosis.

    • The Aortic Dissection Detection Risk Score (ADD-RS) in combination with D-dimer has been proposed and internally validated as a diagnostic algorithm. There are significant caveats:
      • Algorithm has not been externally validated.
      • Half of the patients in the study did not get definitive imaging and follow up was only 14 days, raising the question of possible missed cases.
      • The American College of Emergency Physicians’ (ACEP) 2014 Clinical Policy advises against using D-dimer alone to rule out AAS, though based on Level C evidence.
      • ADD-RS and D-dimer are not meant to diagnose AAS, but rather, to provide guidance in risk stratification for who merits imaging.
    • Consider using this risk stratification algorithm in patients considered low risk for aortic dissection but with uncertainty that the diagnosis can be ruled out.
    • ADD-RS scores range from 0-3, as patients can only get one point from each category (predisposing conditions, pain features, exam findings). Thus, the score does not account for a patient that may have 2 points in a given category. Patients with multiple points in a given category may not be appropriate for the algorithm.
    • May reduce misdiagnosis of AAS.
    • May reduce over-testing for AAS (avoiding radiation and cost associated with definitive imaging).


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    Next Steps
    Creator Insights


    • For ADD-RS >1, consider proceeding directly to CTA or other conclusive imaging.
    • For ADD-RS ≤1, proceed to D-dimer testing. If dimer <500 ng/mL, consider stopping workup of dissection; if ≥500 ng/mL, consider CTA.

    Critical Actions

    • Use in conjunction with other diagnostics to address other emergent, more common causes of chest pain.
    • In patients with high pretest probability of AAS, consider empirically treating hypertension/tachycardia if there is any delay in getting conclusive imaging.


    Addition of the selected points:



    Any high risk condition

    Marfan syndrome

    1 point

    Family history of aortic disease

    Known aortic valve disease

    Recent aortic manipulation

    Known thoracic aortic aneurysm

    Any high risk pain feature

    Chest, back, or abdominal pain described as any of the following:

    • Abrupt onset
    • Severe intensity
    • Ripping or tearing

    1 point

    Any high risk exam feature

    Evidence of perfusion deficit (pulse deficit, systolic BP differential, or focal neurological deficit in conjunction with pain)

    1 point

    New murmur of aortic insufficiency (with pain)

    Hypotension or shock state


    Facts & Figures





    Consider proceeding directly to CTA or other conclusive imaging.


    Proceed to D-dimer testing.  If dimer <500 ng/mL, consider stopping workup of dissection, if ≥500 ng/ml, consider CTA.


    Evidence Appraisal

    In 2010, the American Heart Association (AHA) and the American College of Cardiology (ACC) released guidelines for diagnosis and management of AAS, including a set of 12 clinical markers of the disease. Rogers et al in 2011 then used retrospective data from the International Registry of Acute Aortic Dissection (IRAD) to validate the sensitivity of these markers. Of 2,538 patients with acute aortic dissection, 2,430 (95.7%) were identified by 1 or more of 12 proposed clinical risk markers.  

    The IRAD investigators (Suzuki et al in 2009) also performed a prospective multicenter study of 220 patients with initial suspicion acute aortic dissection, of whom 87 were ultimately diagnosed with acute aortic dissection. The widely used cutoff of 500 ng/mL also showed promise with regard to ruling out AAS, with a negative likelihood ratio (LR-) of 0.07 throughout the first 24 hours, and a sensitivity of 96.6%.

    The ADvISED Trial (Nazerian et al, 2018), working off of the foundation of the above two studies, designed and tested the ADD-RS / D-Dimer novel clinical pathway for ruling out acute aortic dissection, combining clinical risk stratification with D-dimer as a serum biomarker. It is a multicenter prospective observational study that enrolled 1,850 consecutive chest pain patients, 241 (13%) of which were diagnosed with AAS.  ADD-RS ≤1 and negative D-dimer demonstrated a sensitivity of 98.8%, NPV 99.7%, and LR- 0.02.


    • Patients can only get one point per category, e.g. a patient with a new AI murmur and a focal neuro deficit and no other high risk features would still get only one point.
    • Half of the patients in the study did not get definitive imaging and follow up was only 14 days, raising the question of possible missed cases.
    • Criteria for entry into the study were determined by the provider.
    • Like all of the above studies, the prevalence of AAS in this study was considerably higher than seen in previous studies.  It is unclear how AAD-RS and D-dimer will perform in lower risk groups.


    Clinical Practice Guidelines

    Research PaperHiratzka LF, Bakris GL, Beckman JA, et al. 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM guidelines for the diagnosis and management of patients with Thoracic Aortic Disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, American Association for Thoracic Surgery, American College of Radiology, American Stroke Association, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons, and Society for Vascular Medicine. Circulation. 2010;121(13):e266-369.Research PaperDiercks DB, Promes SB, Schuur JD, et al. Clinical policy: critical issues in the evaluation and management of adult patients with suspected acute nontraumatic thoracic aortic dissection. Ann Emerg Med. 2015;65(1):32-42.e12.
    Dr. Peiman Nazerian

    About the Creator

    Peiman Nazerian, MD, is an internist in the emergency department at the Careggi University Hospital in Florence, Italy. He is an instructor in emergency ultrasound and has taught multiple courses in Italy and internationally. Dr. Nazerian's primary research interests are in pulmonary embolism and aortic dissection in the emergency setting.

    To view Dr. Peiman Nazerian's publications, visit PubMed

    Content Contributors
    • Seth Crockford, MD
    About the Creator
    Dr. Peiman Nazerian
    Content Contributors
    • Seth Crockford, MD