COMMENTARY

Painless Aortic Dissection in the Emergency Department

Amal Mattu, MD

Disclosures

September 15, 2017

Clinical Profile of Patients of Acute Aortic Dissection Presenting to the ED Without Chest Pain

Fan KL, Leung LP
Am J Emerg Med. 2017;35:599-601

Background

Acute aortic dissection (AAD) is one of the "big four" deadly threats in emergency department (ED) patients presenting with chest pain—the other three being acute coronary syndrome, pulmonary embolus, and pericarditis/tamponade. Even though AAD is the rarest of the four conditions (it is estimated that a US emergency physician will diagnose an AAD every 3-4 years[1]), it is the most rapidly fatal and, therefore, we are taught to consider it in every patient presenting with chest pain. However, literature has emerged in recent years suggesting that a significant number of patients with AAD do not present with acute chest pain,[2] and this contributes to a large number of misdiagnoses[3,4] and medical malpractice cases. Fan and Leung performed a study to investigate the characteristics of patients with AAD who present without chest pain.

Study Summary

The authors performed a retrospective observational study comparing patients with AAD presenting with chest pain versus those presenting without chest pain. The study was conducted at a tertiary and quaternary referral center in Hong Kong with an annual ED attendance of 120,000 patients.

Between January 1, 2004, and August 31, 2015, 141 patients with AAD were identified. Sixty-one patients (43%) did not have chest pain on presentation to the ED.

No significant differences in risk factors were identified among patients with and those without chest pain. However, the following were identified among patients without chest pain:

  • There was a trend toward more frequent "nonurgent" triage (21% vs 10%);

  • A greater number had thoracic aortic aneurysm (26% vs 13%);

  • They were more likely to present with abdominal pain (36% vs 13%) or back pain (44% vs 28%);

  • They were less likely to present with abrupt onset of pain (31% vs 48%);

  • They were more likely to present in shock (21% vs 8%);

  • They were less likely to present with ischemic changes on the ECG (15% vs 36%);

  • They were less likely to get ECGs (85% vs 99%) and chest radiography (85% vs 98%);

  • There was a trend toward more Stanford type B dissections (38% vs 26%); and

  • There were trends toward a lower likelihood of being diagnosed in the ED (44% vs 56%) and higher likelihood of dying within 30 days of ED presentation (15% vs 11%).

Several interesting findings pertaining to AAD in general (for patients with and those without chest pain) are worth noting as well:

  • The "classic" description of AAD as "ripping" or "tearing" was rare in both groups (7% in patients without chest pain vs < 2% in patients with chest pain);

  • The "classic" description of AAD as severe in intensity was uncommon in both groups (21% in patients without chest pain vs 14% in patients with chest pain);

  • Overall, 7% of patients presented with loss of consciousness/syncope; and

  • Only 58% of patients without chest pain and 54% of patients with chest pain presented with a widened mediastinum on chest x-ray.

Viewpoint

Sir William Osler was referring to the difficulties of diagnosing AAD when he stated that "[t]here is no disease more conducive to clinical humility than aneurysm of the aorta."[5]

The "classic" description of a patient with AAD presenting to the ED is one of abrupt onset of severe, ripping or tearing-type of pain, with maximal intensity at onset and in association with upper back pain, hypertension, and a widened mediastinum on chest x-ray. Unfortunately, "classic" for most medical conditions exists only in textbooks and board exams.

This study nicely demonstrates many atypical features of AAD in the real world, and it reminds us most of all that we cannot feel reassured by the absence of chest pain. These chest-pain–free presentations were associated with a higher likelihood of misdiagnosis or delays in diagnosis, a higher likelihood of presenting in overt shock, and a higher mortality.

I've consulted on three medical malpractice cases for missed AAD in recent years; only one presented with chest pain. Unfortunately, that patient died soon after arrival to the ED, and nothing could have been done to save the patient. The case was eventually dropped.

The other two cases were more difficult to defend. In both cases, the patients presented with pain in the lower torso or legs and with vague neurologic symptoms. The "classic" presentation of abrupt severe chest pain was absent, and the patients were worked up for alternative diagnoses. In neither case was the proper diagnosis of AAD actually made until autopsy. In retrospect, I still believe that those were incredibly difficult diagnoses to make, and studies such as this one by Fan and Leung help to explain that difficulty.

This and other studies are forcing us to rewrite the "classic" description of how AAD presents to the ED. Given how varied the presentations are, we must always consider the possibility of AAD in patients who look sick, whether or not they have chest pain.

Abstract

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....