Guidelines recommending that blood pressure be measured in both arms have additional support in the results of a recent systematic review and meta-analysis published early online by The Lancet.
“Our findings suggest that a difference in SBP of 10 mmHg or more or 15 mmHg or more between arms could identify patients at high risk of asymptomatic peripheral vascular disease and mortality who might benefit from further assessment,” wrote Dr. Christopher E. Clark of the Primary Care Research Group at Peninsula College of Medicine & Dentistry in Exeter, UK, and colleagues.
Included in the meta-analysis were 20 studies published before July 2011. In two pooled datasets, a blood pressure difference of at least 10 mmHg was associated with an 8.8 risk ratio for subclavian stenosis of more than 50% occlusion at angiography.
Between arm blood pressure differences of 15 mmHg or more had a significant association with cerebrovascular disease in a pooled analysis of five cohorts. This degree of difference also was linked to peripheral vascular disease in the leg in nine noninvasive studies, and pooled data from five noninvasive studies with differences in systolic blood pressure of 10 mmHg or more showed a significant association with peripheral vascular disease.
In addition, three studies showed a link between reduced survival and a blood pressure difference of 10 mmHg or more, 15 mmHg or more, or both, and there was a significant relationship between cardiovascularrelated mortality and a difference of 15 mmHg or more in four cohorts (two studies).
“Findings from our study should be incorporated into future guidelines for hypertension and blood pressure measurement to justify bilateral brachial measurement in the assessment of individuals and to promote targeted screening for peripheral vascular disease and aggressive risk factor management in subjects with a demonstrable systolic between-arm difference,” the study authors wrote.
The study was funded by the Royal College of General Practitioners, South West GP Trust, and Peninsula Collaboration for Leadership in Applied Health Research and Care.
An accompanying editorial written by Dr. Richard J. McManus of the University of Oxford and Dr. Jonathan Mant of the University of Cambridge agreed that the results support guidelines recommending blood pressure be measured in both arms.
“The high specificity (96%) of the association between a difference in systolic blood pressure between arms of more than 15 mmHg and peripheral vascular disease justifies use of this measure as a sign of disease,” Drs. McManus and Mant wrote. “The high prevalence of differences in some of the studies suggests that many people with hypertension will be missed when blood pressure is measured in only one arm.”