Ten-Year Update on AAAs
Ten-Year Update on AAAs
Abstract & Commentary
By Michael H. Crawford, MD, Dr. Crawford is Professor of Medicine, Chief of Cardiology, University of California, San Francisco.He is editor of Clinical Cardiology Alert, and is on the speaker's bureau for Pfizer. This abstract first appeared in the May 2008 issue of Clinical Cardiology Alert.
Source: Freiberg S, et al. Circulation. 2008;117:1010-1017.
One-time screening for abdominal aortic Aneurysms (AAA) is recommended in older men, but there is little long-term data on the value of such screening, especially in women. Thus, Freiberg and colleagues from the Cardiovascular Health Study (CHS) evaluated 4734 men and women over age 65 at enrollment in 1992-1993 who had B-mode ultrasound of the abdominal aorta. Aortic diameter was measured above and below the renal arteries in a standard fashion. Two criteria were used to diagnose AAA: an infrarenal aortic diameter > 3.0 or an infrarenal to suprarenal diameter ratio < 1.2. The subjects were contacted twice a year to obtain medical information. The primary outcome variables were: surgical repair, total mortality, and incident cardiovascular events. One or both criteria for AAA were met by 416 subjects; 13% of men and 6% of women. By 2002, there had been 56 surgical repairs and ten AAA-related deaths (six with surgery). The best predictor of subsequent surgical repair was an infrarenal diameter of > 2.5cm (sensitivity and specificity of 90%). Among those that died, all of their infrarenal aortic diameters were > 6.5 cm and three were > 9 cm. An AAA at baseline was associated with a higher mortality (RR 1.44, 95% C1 1.25-1.66) and more cardiovascular events (RR 1.52, 1.25-1.85). AAA also predicted the presence of chronic kidney disease. Freiberg et al concluded that a one-time screening of men and women over age 65 years for AAA can identify those at risk for AAA complications, cardiovascular events, and death,
Commentary
This study is consistent with previous studies that demonstrated the value of one-time screening for AAA in older men, and affirms the lower prevalence of AAA in women. However, the incidence in women was not inconsequential at 6%. It is not surprising that infrarenal aortic size predicted AAA surgery, complications, and death, but other cardiovascular events were also predicted. It has long been recognized that there was an overlap in aortic disease patients and cardiac disease patients, but it has not been clear whether this was the coincidental association of AAA with the more common atherosclerotic vascular disease spectrum. The confusion arises because we have other diseases of the aorta which can lead to aneurysm formation which have little to do with atherosclerosis (eg, Martens). This study seems to support the same disease spectrum hypothesis. Consequently, AAA screening may identify patients with atherosclerotic vascular disease who need appropriate therapy. An infrarenal diameter > 2 cm would suggest atherosclerosis in this study in men and women. Thus, abdominal ultrasound now joins high-sensitivity CRP, LDL cholesterol, and coronary CT screening as methods for identifying subclinical atherosclerosis. Abdominal ultrasound also identifies AAA which is eminently treatable now, often with percutaneous devices.
One-time screening for abdominal aortic Aneurysms (AAA) is recommended in older men, but there is little long-term data on the value of such screening, especially in women.Subscribe Now for Access
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