EBQ:IRAD

Under Review Journal Club Article

Hagan PG et al.. "The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease.". JAMA. 2000. 283(7):897-903.
PubMed Full text PDF

Clinical Question

To assess the presentation, management, and outcomes of acute aortic dissection.

Conclusion

Acute aortic dissection presents with a wide variety of manifestations and classic findings on history, examination, ECG, and chest roentography are often absent.

Major Points

• This large (464 patients), multi-center study assessed 290 variables either at presentation or via retrospective chart review to determine the demographics, history, physical examination findings, management, imaging studies, and outcomes among patients presenting with acute aortic dissection.
• While abrupt onset and severe pain, were the most common historical findings, tearing (50.6%) and chest pain (72.7%) were less common than anticipated. 4.5% of patients presented with no pain at all.
• Aortic insufficiency murmur (31.6%) and pulse deficit (15.1%) were rare.
• Chest radiographs were "normal" in 12.4%. Widened mediastinum was present in only 61.6%.

Study Design

• Multi-center registry of all patients sent to 12 large referral centers in six countries between January 1, 1996 and December 31, 1998.
• Patients were identified at presentation or by searching hospital discharge diagnosis records, surgical records, and echocardiography laboratory databases.
• A 290 variable questionnaire using standard definitions was completed for each patient.
• External validation was performed through as random field selection and error audit in 33% of records.

Population

• All patients presenting with aortic dissection or identified on review of hospital discharge diagnosis records, surgical records, and echocardiography laboratory databases.
• There were no exclusion criteria.

Interventions

• None

Outcomes

Demographics

Patient Demographics

• Mean Age: 63.1 years
• Male Sex: 65.3%
• Referral from Primary Site to IRAD Center: 60.3%
• Ethnicity:
  • White: 82.8%
  • Asian: 13.5%
  • Black: 1.7%
  • Other: 2.0%

Patient History

• Marfan Syndrome: 4.9%
• Hypertension: 72.1%
• Atherosclerosis: 31.0%
• Known Aortic Aneurysm: 16.1%
• Prior Aortic Dissection: 6.4%
• Diabetes Mellitus: 5.1%

Prior Cardiac Surgery

• Aortic Valve Replacement: 5.4%
• Aortic Aneurysm and/or Dissection: 9.7%
• Coronary Artery Bypass Graft: 4.3%
• Mitral Valve Surgery: 0.7%

Iatrogenic Cases

• Catheterization/PTCA: 2.2%
• Cardiac Surgery: 2.2%

Presenting Signs and Symptoms

Presenting Symptoms

• Any Pain Reported: 95.5%
• Abrupt Onset: 84.8%
• Chest Pain: 72.7%
  • Anterior Chest Pain: 60.9%
  • Posterior Chest Pain: 35.9%
• Back Pain: 53.2%
• Abdominal Pain: 29.6%
• Severe or Worst Ever Pain: 90.6%
• Sharp Pain: 64.4%
• Tearing or Ripping Pain: 50.6%
• Radiating Pain: 28.3%
• Migrating Pain: 16.6%
• Syncope: 9.4%

Physical Examination Findings

• Hemodynamics
  • Hypertensive (SBP > 149 mm Hg): 49.0%
  • Normotensive (SBP: 100-149 mm Hg): 34.6%
  • Hypotensive (SBP < 100 mm Hg): 8.0%
  • Shock or Tamponade (SBP < 80 mm Hg): 8.4%
• Aortic Insufficiency Murmur: 31.6%
• Pulse Deficit: 15.1%
• Stroke: 4.7%
• Congestive Heart Failure: 6.6%

Radiographic Findings

• No Abnormalities Noted: 12.4%
• Absence of Widened Mediastinum or Abnormal Aortic Contour: 21.3%
• Widened Mediastinum: 61.6%
• Abnormal Aortic Contour: 49.6%
• Abnormal Cardiac Contour: 25.8%
• Displacement/Calcification of the Aorta: 14.1%
• Pleural Effusion: 19.2%

ECG Findings

• No Abnormalities Noted: 31.3%
• Non-specific ST-segment or T-wave Changes: 41.4%
• Left Ventricular Hypertrophy: 26.1%
• Ischemia: 15.1%
• Myocardial Infarction (Old Q Waves): 7.7%
• Myocardial Infarction (New Q Waves or ST Segments): 3.2%

Initial Imaging Modality

• Computed Tomography: 61.1%
• Echocardiography (TEE and/or TEE): 32.7%
• Aortography: 4.4%
• Magnetic Resonance Imaging: 1.8%

Management and Outcomes

Type A

• Surgical: 72%
• Medical: 28%
• Total Mortality: 34.9%

Type B

• Surgical: 20%
• Medical: 80%
• Total Mortality: 14.9%

Criticisms & Further Discussion

• It is unclear how much of the information was obtained prospectively versus retrospectively. As with any retrospective study, there are inherent limitations when using abstracted chart review data, which include, but are not limited to poor documentation and limited abstraction when different phrasing is used.
• Since the study was conducted only at high volume referral sites, the data may not be applicable to the general community.
• Only patients who were alive at the time of the diagnosis were studied.
• Aortic dissection is a dynamic presentation and some of the more "classic" findings may have developed later in the hospital course.

Funding

• None

Sources

• http://jama.jamanetwork.com/article.aspx?articleid=192401

Authors

Michael Gottlieb, Daniel Ostermayer