Two-Arm Blood Pressure Checks May Spot "Silent" Risks

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Main Category: Hypertension
Also Included In: Cardiovascular / Cardiology;  Heart Disease
Article Date: 30 Jan 2012 - 2:00 PST

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A new study appears to support the idea that blood pressure checks should be done in both arms. Researchers at the University of Exeter Peninsula College of Medicine and Dentistry (PCMD) in the UK reviewed evidence covering differences in systolic blood pressure between arms and found it could be a useful way to spot elevated risk of vascular disease and even death in cases that might otherwise be "clinically silent".

Findings of the systematic review and meta-analysis are published online in The Lancet on 30 January.

Dr Christopher Clark, Clinical Academic Fellow at PCMD and a practising GP in Witheridge, Devon, led the study. He told the press:

"Our findings indicate a strong association, and that differences of 10mm Hg or 15mm Hg or more might help to identify patients who are at risk and who need further vascular assessment," said Clark.

However, he cautioned that more studies are needed before these conclusions can apply usefully to clinical settings:

"But in the meanwhile we will be flagging the results of our review to the UK Vascular Check programme," said Clark.

Blood pressure is the amount of pressure the blood puts on the walls of arteries as the heart pumps it around the body. Two readings are taken when measuring blood pressure: systolic, when the heart is compressing, and diastolic, when the heart is relaxed. For example a reading of 120/80 means a pressure of 120 mm of mercury (Hg) systolic and 80 mm diastolic.

Usually, in health checks, blood pressure measures are taken from one arm. But some studies have shown that differences in systolic blood pressure between arms have been linked with peripheral vascular disease, probably due to subclavian stenosis, a narrowing and hardening of one of the two artery systems, located under the collarbone, that feed the left or right arm.

For their study, Clark and colleagues searched publications databases for articles that covered differences in systolic blood pressure between arms. They looked for those that contained data on subclavian stenosis, peripheral vascular disease (narrowing and hardening of the arteries that supply blood to the extremities) , cerebrovascular disease (affecting blood supply to the brain and often linked to cognitive issues such as dementia), cardiovascular disease, and survival.

They found 28 papers, of which 20 had the right sort of data for their meta-analysis.

When they pooled and analyzed the data, they found significant evidence to suggest a difference of 15 mm Hg or more in systolic blood pressure (SBP) was linked to an increased risk of peripheral vascular disease, pre-existing cerebrovascular disease, and mortality, both as a result of cardiovascular problems and generally.

They also found that the risk of peripheral vascular disease increased at a difference of 10mm Hg or more in SBP.

The authors conclude:

"A difference in SBP of 10 mm Hg or more, or of 15 mm Hg or more, between arms might help to identify patients who need further vascular assessment. A difference of 15 mm Hg or more could be a useful indicator of risk of vascular disease and death."

They say the findings support the need for blood pressure checks in both arms to be the norm, not least because most cases present as "clinically silent" and checking in both arms would be a better way to find those at risk.

The Royal College of General Practitioners, the South West GP Trust and the National Institute for Health Research Peninsula Collaboration for Leadership in Applied Health Research and Care support the study.

Written by Catharine Paddock PhD
Copyright: Medical News Today
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