TUESDAY, March 20 (HealthDay News) -- Calculating the difference in blood pressure readings taken from the left and right arms might help predict a patient's odds of dying from heart disease, a new study suggests.
Researchers found that people with high blood pressure whose blood pressure varies significantly between each arm are at higher risk of cardiovascular death over 10 years.
The study supports "inter-arm difference as a simple indicator of increased cardiovascular risk," say a team led by Dr. Andrew Gould, of the Peninsula College of Medicine and Dentistry in Plymouth, England.
The new findings echo those of a study published in January in The Lancet. That study, also conducted by researchers at Peninsula College, reviewed data from 28 studies looking at differences between systolic blood pressure [the top number in a reading] between the right and left arms.
The team found that a difference of 15 millimeters of mercury (mm Hg) or more between readings was linked with an increased risk of narrowing or hardening of the arteries supplying the lower limbs, called peripheral vascular disease.
In the new study, Gould and colleagues looked at 230 patients with high blood pressure. They found that, after adjusting for age and gender, there was a 9 percent increased risk of death over the next 10 years for every one mm/Hg difference in blood pressure reading between the arms.
The findings suggest that blood pressure should be routinely measured in both arms for patients undergoing treatment for hypertension, the researchers report March 20 in the online edition of the BMJ.
One expert in the United States agreed with the findings.
"As the recent article points out, blood pressure readings in the right and left arm may differ by a few points," said Dr. Kevin Marzo, chief of cardiology at Winthrop-University Hospital in Mineola, N.Y. "However, a difference of more than 10 points [mm/Hg] could suggest trouble and alert the physician to intensify treatment strategies for preventing a heart attack or stroke. The 'vital' signs should include blood pressure in both arms -- a screening test that adds no cost, little time and potentially so critical to initiating lifesaving treatment.'
For patients found to have different blood pressure readings in their arms, subsequent monitoring should be performed in the arm with the higher reading because doing so would help determine necessary treatment, Dr. Dae Hyun Kim of Harvard Medical School added in an accompanying journal editorial.
Further research is needed to establish the link between different blood pressure readings in the arm and death risk, Kim added.
The American Academy of Family Physicians has more about high blood pressure.
-- Robert Preidt
SOURCES: Kevin Marzo, M.D., chief of cardiology, Winthrop-University Hospital, Mineola, N.Y.; British Medical Journal, news release, March 20, 2012
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