Thoracic Aortic Syndromes in The Emergency Department: Recognition and Management

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Points

• Acute aortic syndromes (AAS) include aortic dissection (AoD), intramural hematoma (IMH), and penetrating atherosclerotic ulcer (PAU).
• AoD is the most prevalent, accounting for 85%-95% of AAS; IMH 5%-25%; and PAU 2%-7%.
• The mortality rate of AoD is 1%-2% per hour after onset of symptoms; untreated, mortality is 90% at 3 months.¹²
• The Stanford classification system is the most used, with type A (proximal) affecting the ascending aorta and type B (distal) affecting the descending aorta. See Figure 1 and Table 1 for other classifications.
• Two-thirds of patients who present with AoD are males aged 50 to 70 years.
• AoD patients aged <40 years are more likely to have a bicuspid aortic valve, Marfan syndrome or other connective tissue disorder, or have had prior aortic surgery.
• Marfan syndrome, Loeys-Dietz syndrome, and Ehlers-Danlos syndrome type IV are connective tissue disorders associated with AoD.
• Half of patients presenting with AoD will be hypertensive and tachycardic. (See Table 3 for occurrence of examination findings in AoD.)
• Hypotension on presentation (8%) usually indicates complications such as tamponade, contained rupture, or myocardial ischemia.⁴
• The ADD-RS (Aortic Dissection Detection Risk Score) is a set of 12 clinical markers of AoD for low to moderate risk patients when AoD is on the differential. 
• D-dimer has low sensitivity and specificity when used alone; a positive D-dimer necessitates further imaging, but a negative D-dimer should be interpreted with caution.
• Electrocardiogram has not been shown to be sensitive or specific in detection of AAS, though it may suggest a cardiac etiology. In patients with high-risk features, further testing is needed.
• Transesophageal echocardiography (TEE) is more accurate than transthoracic echocardiography (TTE) for identifying and ruling out acute proximal AoD.
• TTE is recommended for patients with aortic regurgitation, pericardial effusion, cardiac tamponade, and wall motion abnormalities.
• CT is the preferred initial imaging modality for evaluation of aortic disease.⁹
• The incidence of true contrast-induced nephropathy is lower than traditionally believed, and guidelines recommend that, in the setting of AoD, contrast should not be withheld.⁵⁸
• Admit all AAS patients to the ICU.
• Ascending type A dissections almost uniformly require surgical intervention.
• Cardiothoracic surgery consult should be obtained for patients with IMH and PAU.
• When resources for operative intervention for AoD with tamponade are limited, controlled pericardial drainage may be used. See “Management of Patients in Shock”.

Pearls

• The most common presenting symptom of AAS is sudden and severe chest pain.
• Type A dissection: anterior chest pain that radiates to back, neck, and abdomen.
• Type B dissection: posterior chest pain that radiates to abdomen.
• Other presenting symptoms include syncope (13%), neurologic deficits (17%), apparent stroke, STEMI (3%), coma, weakness, flank pain (5%), and back pain. The symptoms typically relate to the location of the dissection.
• Contrary to classical teaching, pain migration has been associated with only 17% of cases.²⁴
• The goal of ED management is stabilization, primarily through control of systolic blood pressure (SBP) and heart rate.
• A rapidly titratable beta blocker is preferred for rate control. (See Table 4.)
• Once heart rate is controlled, SBP should be maintained at 100-220 mm Hg.^4,5

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Aortic Dissection Detection Risk Score (ADD-RS)

• Introduction
• About the Score
• Calculator Review Author
• Evidence Appraisal
• Calculator Creator
• References

Introduction

The ADD-RS rules out aortic dissection

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About the Score

The Aortic Dissection Detection Risk Score (ADD-RS) should be used for low- to moderate-risk patients for whom acute aortic syndromes (AAS) are in the differential diagnosis. This tool, used in combination with a D-dimer test, has been proposed and internally validated as a diagnostic algorithm. There are significant caveats to the tool, including the following:

• The algorithm has not been externally validated.
• Half of the patients included in the original study did not have definitive imaging, and the study limitation of 14 days of follow-up raises the possibility of missed cases.
• The American College of Emergency Physicians’ 2014 Clinical Policy on thoracic aortic dissection advises against using D-dimer alone to rule out AAS, though this recommendation is based on Level C evidence.
• ADD-RS and D-dimer are not meant to diagnose AAS, but rather to provide guidance in in risk stratifying patients for imaging.

The ADD-RS may reduce misdiagnosis and overtesting for AAS, thereby avoiding unnecessary radiation exposure and the cost associated with definitive imaging. Consider using this risk stratification algorithm in patients who are at low risk for aortic dissection but for whom the diagnosis cannot be ruled out. The ADD-RS has a scoring range of 0 to 3; patients can be given just 1 point for each category (predisposing conditions, pain features, and exam findings). Thus, the score does not account for a patient who meets multiple criteria within a category. Patients meeting multiple criteria in a given category may not be appropriate candidates for the algorithm.

Calculator Review Authors

Evidence Appraisal

In 2010, the American Heart Association and the American College of Cardiology released guidelines for the diagnosis and management of AAS, including a set of 12 clinical markers of the disease. Rogers et al (2011) used retrospective data from the International Registry of Acute Aortic Dissection to validate the sensitivity of these markers. Among 2538 patients with acute aortic dissection, 2430 patients (95.7%) were identified by 1 or more of the 12 proposed clinical risk markers.

The International Registry of Acute Aortic Dissection investigators (Suzuki 2009) also performed a prospective multicenter study of 220 patients with initial suspicion for acute aortic dissection. Eighty-seven of those patients were ultimately diagnosed with acute aortic dissection. The widely used D-dimer cutoff of <500 ng/mL showed promise for ruling out AAS, with a negative likelihood ratio of 0.07 through the first 24 hours and a sensitivity of 96.6%.

The authors of the ADvISED trial (Nazerian 2018) 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. This multicenter prospective observational trial enrolled 1850 consecutive chest pain patients, 241 (13%) of whom were diagnosed with AAS. An ADD-RS score of ≤1 and a negative D-dimer result demonstrated a sensitivity of 98.8%, a negative predictive value of 99.7%, and a negative likelihood ratio of 0.02. The shortcomings of this study included the following:

• Patients could receive only 1 point per category (eg, a patient with a new aortic insufficiency murmur, a focal neuro deficit, and no other high risk features would still be given just 1 point).
• The criteria for entry into the study were determined by the clinician.
• As with all of the studies described here, the prevalence of AAS found in this study was considerably higher than in previous studies. It is unclear how AAD-RS and D-dimer will perform in lower-risk groups.

Calculator Creator

Peiman Nazerian, MD

References

Original/Primary Reference

• Rogers AM, Hermann LK, Booher AM, et al. Sensitivity of the aortic dissection detection risk score, a novel guideline-based tool for identification of acute aortic dissection at initial presentation: results from the International Registry of Acute Aortic Dissection. Circulation. 2011;123(20):2213-2218. DOI: 10.1161/CIRCULATIONAHA.110.988568
• Nazerian P, Mueller C, Soeiro AM, et al. Diagnostic accuracy of the aortic dissection detection risk score plus D-dimer for acute aortic syndromes: the ADvISED Prospective Multicenter Study. Circulation. 2018;137(3):250-258. DOI: 10.1161/CIRCULATIONAHA.117.029457

Additional References

• Suzuki T, Distante A, Zizza A, et al. Diagnosis of acute aortic dissection by D-dimer: the International Registry of Acute Aortic Dissection Substudy on Biomarkers (IRAD-Bio) experience. Circulation. 2009;119(20):2702-2707. DOI: 10.1161/CIRCULATIONAHA.108.833004
• Hiratzka 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-e369. DOI: 10.1161/CIR.0b013e3181d4739e
• Diercks DB, Promes SB, Schuur JD, et al.Clinical policy: critical issues in the evaluation and management of adult patients with suspected acute nontraumatic thoracicaortic dissection.Ann Emerg Med. 2015;65(1):32-42.DOI: 10.1016/j.annemergmed.2014.11.002