Differences in blood pressure between arms increase the risk of heart attack, stroke

If your doctor finds that the blood pressure measurements between your two arms are different, you may be at increased risk for chest pain, heart attack and stroke, a large new study finds.

The study, which was a re-analysis of data from 24 international studies involving nearly 54,000 patients, found that a difference of 10 mmHg or higher between the two arms increased the 10-year risk of cardiovascular events and death. According to the report published in hypertension, the risk of angina, heart attack and stroke for each grade increased by more than 10 mmHg by 1%.

“Blood pressure should be measured in both arms during cardiovascular assessment, not only to identify the higher reading arm, but also to identify the additional risk posed by a difference between the arms,” ​​said the study’s lead author, Dr. Chris Clark, a clinical senior lecturer in general practice at the University of Exeter College of Medicine and Health in England.

Based on the new findings, Clark and his colleagues say a difference of more than 10 mmHg between the two arms should be of concern.

“We think the difference we measure is caused by changes that lead to choking of the veins,” Clark said in an email. “Stiff veins are associated with cardiovascular events and death.”

While it may seem like lower blood pressure in one arm may be good news, the opposite is true.

“It is likely that significant differences in blood pressure between the left and right arms indicate a narrowing of the main arteries due to atherosclerosis (an accumulation of fats, cholesterol and more on the arterial walls),” the study co-author said. , dr. Mary, said. McDermott, a professor at Northwestern University Feinberg School of Medicine in Chicago.

“The arm with the lower blood pressure probably has blockages in the arterial flow that causes the lower blood pressure,” McDermott said in an email.

To take a closer look at the importance of different readings between arms, the researchers searched the medical literature for studies that included blood pressure measurements of both arms and long-term health outcomes.

They eventually focused on 24 studies that included data from 53,827 patients.

The new study is an ‘important paper’, said dr. Matthew Muldoon, a professor of medicine at the University of Pittsburgh School of Medicine and director of the UPMC Heart and Vascular Institute Hypertension Center, said. “This is the most important article to address the issue of hypertension,” said Muldoon, who was not involved in the new research.

One limitation of the study is that it did not address the variability of blood pressure from moment to moment even in one arm, Muldoon said. “When you measure your blood pressure repeatedly, it is not stable,” he added.

The study nevertheless shows that the differences in blood pressure between the arms are associated with a higher risk of cardiovascular events. And the higher risk may be enough to help doctors convince patients that it is necessary to lower blood pressure.

While the authors suggest that doctors regularly measure blood pressure in both arms, this is unlikely to happen because there is already so much to cover at each visit.

One solution might be for patients to measure their blood pressure in both arms on their own.

“I’m a fan of using patients in the management of high blood pressure,” Muldoon said. ‘Automatic shackles are not expensive. In some respects, it is more practical to expect patients to do so. ”

The American Heart Association offers some tips on how to get the most accurate blood pressure measurements:

  • Clean up your schedule and relax: Do not smoke, drink caffeinated beverages or exercise 30 minutes before measuring your blood pressure, and empty your bladder to make sure you rest quietly for at least five minutes before the measurement.
  • Your body position is important: Sit with your back straight and supported (a dining chair will be better than, for example, a sofa). Place your feet flat on the floor and do not cross your legs. Place your arm on a flat surface for support with the upper arm at heart level. Make sure the cuff sits directly above the bend in your elbow.
  • The cuff should be directly on your skin: Do not take the measurements over your clothes.
  • Take the same time every day: Read best every day at the same time, such as morning or evening.
  • Take several measurements and record all the results: Each time your blood pressure, make two or three measurements per minute apart. If your monitor has built-in memory to store the readings, take them with you to your doctor’s appointments.

Consult your doctor if your numbers are related. It is helpful to keep a record of previous readings for an informed discussion of your risk and next steps.