Cardiology
-
Multicenter Study Clinical Trial
Aortic Size Distribution in the General Population: Explaining the Size Paradox in Aortic Dissection.
Current guidelines recommend a diameter of 5-5.5 cm as the threshold for surgery on the ascending aorta. However, a study from the International Registry of Acute Aortic Dissection showed that nearly 60% occurred at <5.5 cm (the 'aortic size paradox')--leading to a debate whether the size threshold should be lowered. However, the study showing dissection at small size had no knowledge of the population at risk. Herein, we aim to calculate the relative risk of aortic dissection at sizes<5.5 cm by analyzing both the number of occurring dissections (numerator) and the population at risk at each aortic size (denominator). ⋯ The normal aorta is deceptively small, most commonly <3.5 cm. The aortic size paradox is a byproduct of the very large number of patients in small size ranges. This study fully supports current recommendations for surgical intervention at 5-5.5 cm.