Tran and Khoynezhad FALSE TRUE A B TRUE FALSE Figure 2 Aortic dissection. Actual specimen (A) and intravascular imaging (B) show both the true and false lumen. refractory pain, or rapid aortic expansion. This is an important distinction as patients with complicated type B AAD usually require immediate endovascular or open surgical intervention. Clinical presentation Insights into the clinical presentation of patients are gained from the International Registry of Acute Aortic dissection (IRAD).6 A prototypical patient with acute aortic dissection will be a man in his ﬁfth to seventh decade of life, whose past medical history is signiﬁcant for hypertension; patients younger than 40 years may report a history of Marfan syndrome, bicuspid aortic valve, Ehlers-Danlos syndrome, Loeys-Dietz syndrome or aortic valve surgery. The most common chief complaint is sudden onset of severe chest pain or back pain. Patients with type A more commonly report a history of anterior chest pain whereas type B more commonly report a history of back or abdominal pain. The pain may be described as sharp, and, less commonly, ripping or tearing, with radiation to back, neck, or abdomen. One out of six Table 1 Characteristics of patients (N = 951) with acute aortic dissection – from the International Registry of Acute Aortic Dissection8 Risk factor % of Patients % of Patients Age 40 years (N = 68) Age 40 years (N = 883) Age, years Type A dissection Type B dissection Male Medical and social history Hypertension* Atherosclerosis* Known aortic aneurysm Bicuspid aortic valve* (N = 516) Known aortic valve disease Marfan syndrome* Peripartum Cocaine-related Diabetes mellitus Previous history of cardiac surgery Aortic valve replacement* CABG Prior history of aortic dissection Note: *Statistically different between the two groups. 56 30.7 68 32 76 34 1 19 9 10 50 3 0 0 12 0 7 63.9 65 35 67 72 30 13 1 8 2 0 0.6 4 5 6 6 Vascular Health and Risk Management 2009:5