Ankle Blood Pressure Test May Spot Hidden Heart Risks

Mar. 11 -- TUESDAY, March 10 (HealthDay News) -- Simple but unconventional tests, such as blood pressure measurement taken at the ankle, could spot people with otherwise unsuspected heart risks, new research shows.

Many people who seem to be at low risk of cardiac problems by conventional standards actually have subtle signs of future trouble, noted a team from Brown University in Providence, R.I.

Traditional screening, which assesses risk factors such as cholesterol, blood pressure and diabetes, "probably has only about 20 percent sensitivity in identifying people at high risk of sudden death," said study lead author Dr. Timothy P. Murphy, professor of diagnostic imaging at Brown. "When you filter out people who have had prior heart attacks and strokes, you are left with a large number of people who are supposed to be at lower risk. They are not considered candidates for intensive therapy to lower that risk. But two-thirds of heart attacks and sudden cardiac deaths occur in that group," he said.

The Brown researchers were expected to present their findings Tuesday at the annual meeting of the Society of Interventional Radiology, in San Diego.

In the study, Murphy's group examined data on more than 6,200 people in the 1999-2004 National Health and Nutrition Examination Survey (NHANES). The researchers pinpointed three unconventional indicators of future cardiac problems: an abnormal ankle brachial index (blood pressure taken at the ankle), elevated blood levels of a clotting factor called plasma fibrinogen, and high levels of C-reactive protein, a marker for inflammation.

While 91 percent of the NHANES group was at low or intermediate risk of cardiovascular problems by conventional standards (based on the long-running Framingham heart study), almost 45 percent of these people fared poorly on least one of the three more unconventional measurements, Murphy said.

Some 3.7 percent had a low ankle brachial index, indicating weaker blood flow to the legs. More than 17 percent had elevated levels of fibrinogen, the major protein of blood clots, and 37.9 percent had high levels of C-reactive protein.