Between-Armdifference in systolic blood pressure (BP) predicts all-cause and cardiovascular mortality, according to a new meta-analysis of individual participant data.
“We should be checking blood pressure in both arms when we’re assessing someone for their cardiovascular health status,” Dr. Chris Clark of the University of Exeter College of Medicine and Health, in the U.K., noted in a Zoom interview with Reuters Health. “The difference between arms can be taken into account for assessing their cardiovascular risk.”
While guidelines recommend that clinicians measure blood pressure in both of a patient’s arms and use the higher number, these guidelines are rarely followed, Dr. Clark said.
He and his colleagues hypothesized that differences in systolic readings between a person’s arms could be “an early marker of changes in the arteries associated with stiffening,” which in turn is a marker for cardiovascular risk.
“Although we recognize blood-pressure regression to the mean and accommodation over time, that is not the full explanation for sequential interarm differences, if you like, which we think is the marker of risk,” Dr. Clark said.
He and his colleagues merged data from 24 studies including nearly 54,000 participants to create the Inter-arm Blood Pressure Difference – Individual Participant Data (INTERPRESS-IPD) Collaboration.
All-cause and CV mortality increased significantly in tandem with systolic interarm differences, with continuous hazard ratios of 1.05 and 1.06, respectively, for each 5 mmHg. All-cause mortality also rose significantly starting at a threshold of 5 mmHg (hazard ratio, 1.07), the researchers report in Hypertension.
The interarm BP difference was associated with cardiovascular events in people with no cardiovascular disease after risk adjustment based on Atherosclerotic Cardiovascular Disease score (HR, 1.04), Framingham score (HR, 1.04) and QRISK cardiovascular disease risk algorithm version 2 (HR, 1.12) score.
“Our data suggest that we should be paying attention to differences of greater than 10 millimeters of mercury, which is a stretch further than the guidelines in Europe and the UK” of 15 mm Hg, Dr. Clark said.
The authors concluded that “systolic interarm difference is associated with increased all-cause mortality, cardiovascular mortality, and cardiovascular events. Blood pressure should be measured in both arms during cardiovascular assessment. A systolic interarm difference of 10 mm Hg is proposed as the upper limit of normal.
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Source: Medscape, Hypertension