Higher Arm Versus Lower Arm Systolic Blood Pressure and Cardiovascular Outcomes: a Meta-Analysis of Individual Participant Data From the INTERPRESS-IPD Collaboration

Abstract

Background: Guidelines recommend measuring blood pressure (BP) in both arms, adopting the higher arm readings for diagnosis and management. Data to support this recommendation are lacking. We evaluated associations of higher and lower arm systolic BPs with diagnostic and treatment thresholds, and prognosis in hypertension, using data from the Inter-arm Blood Pressure Difference—Individual Participant Data Collaboration. Methods: One-stage multivariable Cox regression models, stratified by study, were used to examine associations of higher or lower reading arm BPs with cardiovascular mortality, all-cause mortality, and cardiovascular events, in individual participant data meta-analyses pooled from 23 cohorts. Cardiovascular events were modelled for Framingham and atherosclerotic cardiovascular disease risk scores. Model fit was compared throughout using Akaike information criteria. Proportions reclassified across guideline recommended intervention thresholds were also compared. Results: We analyzed 53 172 participants: mean age 60 years; 48% female. Higher arm BP, compared with lower arm, reclassified 12% of participants at either 130 or 140 mm Hg systolic BP thresholds (both P< 0.001). Higher arm BP models fitted better for all-cause mortality, cardiovascular mortality, and cardiovascular events (all P <0.001). Higher arm BP models better predicted cardiovascular events with Framingham and atherosclerotic cardiovascular disease risk scores (both P <0.001) and reclassified 4.6% and 3.5% of participants respectively to higher risk categories compared with lower arm BPs). Conclusions: Using BP from higher instead of lower reading arms reclassified 12% of people over thresholds used to diagnose hypertension. All prediction models performed better when using the higher arm BP. Both arms should be measured for accurate diagnosis and management of hypertension. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: CRD42015031227.

Clinical relevance of double‐arm blood pressure measurement and prevalence of clinically important inter‐arm blood pressure differences in Indian primary care

“…Recent evidence showed that concordance of the higher BP arm‐side was 63% overall, rising to 73% and 92% when the mean IAD was equal to or higher than 5 and 10 mmHg, respectively. This confirms consistency of IADs, especially where the average IAD was equal to or higher than 10 mmHg 28 . In addition, Clark and associates found in their meta‐analysis that an IAD of 10 mmHg or more was associated with peripheral vascular disease.…”

“…This confirms consistency of IADs, especially where the average IAD was equal to or higher than 10 mmHg. 28 In addition, Clark and associates found in their meta-analysis that an IAD of 10 mmHg or more was associated with peripheral vascular disease. This finding was based on 20 studies of which the majority did not use the consistency method.…”

“…We recently found a positive hazard for smoking in our individual participant data modeling of all-cause mortality taking account of IAD, although total cholesterol appeared to have a negative relationship. 6,43 The presence of AF is associated with peripheral artery disease. 44 A systolic IAD ≥ 15 mmHg has previously been labelled subclavian stenosis, and it indicates a 2.5 times risk of presence of peripheral artery disease in comparison with lower IADs.…”

“…[1][2][3][4] Inter-arm differences (IAD) in BP have been associated with peripheral arterial disease and increased cardiovascular and all-cause mortality. 5,6 Despite these recommendations, bilateral BP measurements are often not performed in routine clinical practice. [7][8][9] This may be due to uncertainties around appropriate methods of bilateral BP measurement and correct interpretation and management of an IAD.…”

“…[14][15][16][17] However, recent evidence has confirmed the prognostic value of sequentially measured arm BPs. 6 The purpose of this study was to 1) determine the prevalence of absolute IADs in BP in a large representative primary care cohort in India, 2) compare prevalence's of IAD with clinically significant IAD cutoff values recommended in international BP guidelines and existing literature, and 3) determine the relationship between IADs and patient characteristics.…”