Blood pressure reading must be taken from both arms to assess heart disease risks

A difference in the arms can indicate a risk for heart diseases even in seemingly healthy people.

Yet another study, a large-scale one, has shown how important it is to take blood pressure reading from both arms to assess risk of cardiovascular diseases. A difference in blood pressure between each arm can signal an increased risk of dying of heart disease not only in those with a heart condition but also in healthy people, was what the Exeter-led research has revealed.

Clinicians continue to monitor the blood pressure only in one arm though it had been shown how differences between the arms is linked with an increased risk of dying from cardiovascular disease in those at high risk or having a pre-condition.

Using data from the Aspirin for Asymptomatic Atherosclerosis (AAA) trial conducted from April 1998 to October 2008 in which 3350 males and females aged 50–75 years living in central Scotland and free of pre-existing clinical cardiovascular disease, the University of Exeter Medical School team worked with the authors of the AAA trial to study the implications of a difference in blood pressure measurement in healthy people with no earlier episode of heart disease or hypertension.

A difference in systolic blood pressure measurements between the two arms (of 5mm Hg) was linked with almost double the risk of death from heart-related disease. Using just one pair of blood pressure readings, 60 per cent of the cohort had this difference.

Accuracy calls for simultaneous measurement in both arms and multiple measurements but the study went along with current practice of testing one arm after the other and a single measurement. Even so, a difference in measurements indicated a higher risk of heart diseases.

The researchers plan to quantify the extra risk that an inter-arm difference indicates and the extent to which this can be protected against.

The research funded by the Royal College of General Practitioners, The South West GP Trust, NIHR and the NIHR CLAHRC South West Peninsula (PenCLAHRC), is published in the British Journal of General Practice.

Dr Chris Clark, a GP and Clinical Senior Lecturer in General Practice at the University of Exeter Medical School, said: "Current guidelines state that blood pressure should be measured in both arms when assessing patients for hypertension, but often this advice is not followed due to time constraints or lack of awareness amongst clinicians… This new study confirms that people identified with only a single pair of measurements are still at higher risk of heart disease than those without an inter-arm difference. Repeated assessments to confirm the existence of an inter-arm difference, and suitable lifestyle advice, can then be targeted at individuals identified in this way, and could make a difference to their future health."