Interarm Blood Pressure Disparities Linked to Heart Attack Risk

A new study suggests that a sizeable difference between blood pressure (BP) readings on the left and right arms could indicate an increased risk of cardiovascular disease (CVD).

Researchers at Massachusetts General Hospital (Boston, USA) conducted a study that examined 3,390 (56.3% female, mean age 61.1 years) participants of the Framingham Heart Study (FHS) who were free of CVD and attended an examination between 1991 and 1994 (original cohort) and from 1995 to 1998 (offspring cohort). The researchers then examined the association between interarm systolic BP difference, incident CVD, and all-cause mortality. An increased interarm systolic BP difference was defined as equal to, or higher than 10 mm Hg.

The results showed that the mean absolute interarm systolic blood BP was 4.6 mm Hg, with an increased interarm systolic BP difference present in 9.4% of participants. Interarm differences of 10 points or more resulted in a 38% risk of heart attack, stroke, or a related problem. Those with an elevated interarm systolic BP difference were older, had a greater prevalence of diabetes mellitus, higher systolic BP, and a higher total cholesterol level. There was no such association with mortality. The study was published in the March 2014 issue of the American Journal of Medicine.

“While most cardiologists routinely measure blood pressure in both arms as part of an initial evaluation, most primary care doctors do not,” concluded lead author cardiologist Christopher O’Donnell, MD. “Our study suggests that a baseline blood pressure measurement in both arms by primary care clinicians may provide additional information about cardiovascular risk prediction.”

Large interarm BP differences suggest the presence of plaque in the vessel that supplies blood to the arm with higher blood pressure, a sign of onset peripheral artery disease (PAD). And when PAD is present, arteries in the heart and brain are also usually clogged, boosting the odds of having a heart attack or stroke. It is recommended that if BP in one arm is higher, that arm should be the one upon which to base any treatments in the future.

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