Do You Know Your ABI? (clue: it’s your ankle-brachial index)

Degenerative arterial disease attacks many vessels in the body, although one usually worries most about changes in the coronary arteries that precipitate heart attack.  This has led to screening tests to investigate coronary arterial disease: CT-scans for calcification, and invasive coronary angiography.  Both these are expensive and carry the risk of excessive radiation.  There are simpler ways of determining arterial disease.  For instance, the presence of erectile dysfunction in men is a predictor of mortality and other cardiovascular events; all  that’s required is a question or two from the physician.  Another simple screening test is the ABI, or ankle-brachial index.  The test compares the blood pressure in the arm (brachial) and near the ankle, and is a direct measure off atheromatous plaque buildup in the leg arteries.  A presentation at the recent Society of Interventional Radiologists described the use of this test in predicting cardiovascular disease.   

Researchers reviewed the results from a study of 822 men and women (average age: 64) that was done at 23 centers nationwide.  The participants did not have known cardiovascular disease or diabetes, but data were available to calculate Framingham risk scores of coronary heart disease.  Three groups were formed: low, intermediate, or high risk, according to Framingham categories.  31% of the participants had a low-risk score, and in this group the ABI was abnormal in 11.3%.  50% of the participants had an intermediate risk score, and 12.8% of these had abnormal ABI tests.  (The abstract presented at the meeting didn’t give the ABI results for the remaining 19% of the participants.)

As stated, a ‘positive’ ABI (ratio of systolic ankle to systolic brachial pressure below 0.9) gives a direct measure of fatty plaque in the leg arteries, and an indirect measure of plaque accumulation throughout the cardiovascular system.  It’s simple to perform and costs less than $200, so you can probably get your doctor to do one on you.  It’s easier, quicker, cheaper, and a lot less worrying than a CT scan for calcium or a cath-lab study.