The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease
Hagan, Peter G., et al. “The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease.” Jama 283.7 (2000): 897-903.
Published in 2000, IRAD was the first big look at characterizing Acute Aortic Dissection as a disease. It was a case series among 12 international referral centers across 6 different countries. 464 Patients were retrospectively enrolled in the study between 1996-1998 after diagnosis had been confirmed. The purpose of this registry was to answer several important general characteristics about Acute Aortic Dissection: Who are the patients presenting with disease, how are these patients presenting, how is the diagnosis being made, how are these patients being managed, and what are their outcomes.
Almost two-thirds (63%) of the patients in the study were male. An overwhelming majority (83%) were white. In terms of patient history, 72% of patients had a history of hypertension, 18% had recent cardiac surgery, and 5% had Marfan syndrome.
Things get interesting when we look at how the patients presented. The most common symptomatic complaints were abrupt (85%) chest pain (72%). This pain was most commonly described as sharp (65%) as opposed to tearing or ripping (50%). Around 9% of patients had syncopized. In terms of physical exam, half the patients (49%) were found to be hypertensive, while a third were normotensive (34%) and the rest were hypotensive.
Classic physical exam findings were notably absent, with only 32% presenting with aortic regurgitation murmur, and only 15% having a noted pulse deficit. From a diagnostic perspective, chest radiography was noted to have widened mediastinum in only 62% of cases, and ECG was completely normal in 31% of cases. Most cases were diagnosed either by CT (61%) or echocardiogram (33%).
What were the patient outcomes? Patients with Type A dissection had a mortality of 26% when managed surgically vs 58% when managed medically. Type B dissection had a mortality of 31% when managed surgically vs 11% when managed medically.
Acute Aortic Dissection is a deadly disease with a wide array of presentations. The classic presentation of tearing chest pain radiating to the back is surprisingly uncommon. So are classic physical and diagnostic findings including murmurs, pulse deficits, and widened mediastinum on radiography. As clinicians we have to maintain a high index of suspicion for this scary disease, regardless of normal vital signs. Keep a particular eye out for patients with a history of hypertension with sharp, abrupt onset of pain (chest, abdomen, or back) without an EKG suggestive of ACS.