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Higher Arm Versus Lower Arm Systolic Blood Pressure and Cardiovascular Outcomes: a Meta-Analysis of Individual
Christopher E Clark1, Fiona C Warren1, Kate Boddy2
1Primary Care Research Group, University of Exeter Medical School, Exeter, Devon, England (C.E.C., F.C.W., S.T.J.M., S.F.M., R.S.T., J.L.C.).
Insights
Measuring blood pressure in both arms and using the higher reading improves hypertension diagnosis and prognosis. This approach enhances accuracy for cardiovascular risk assessment and patient management.
Area of Science:
- Cardiology
- Hypertension Research
- Clinical Epidemiology
Background:
- Current guidelines recommend bilateral arm blood pressure (BP) measurement, utilizing the higher reading for hypertension diagnosis and management.
- Evidence supporting this recommendation, particularly regarding prognostic implications, is limited.
- This study addresses the data gap by evaluating the association of higher and lower arm systolic BPs with diagnostic thresholds and patient prognosis.
Purpose of the Study:
- To assess the impact of using higher vs. lower arm systolic blood pressure (BP) readings on hypertension diagnosis and cardiovascular risk prediction.
- To determine if higher arm BP measurements improve the accuracy of cardiovascular event prediction models.
- To provide evidence for optimizing blood pressure measurement protocols in clinical practice.
Main Methods:
- Individual participant data meta-analysis from 23 cohorts, including 53,172 participants.
- One-stage multivariable Cox regression models were used to analyze associations between higher/lower arm BPs and mortality/cardiovascular events.
- Model fit and reclassification across intervention thresholds were compared using Akaike information criteria and standard methods.
Main Results:
- Using higher arm BP reclassified 12% of participants across key systolic BP thresholds (130/140 mmHg).
- Models incorporating higher arm BP demonstrated superior fit for all-cause mortality, cardiovascular mortality, and cardiovascular events.
- Higher arm BP improved prediction of cardiovascular events using Framingham and atherosclerotic cardiovascular disease risk scores, reclassifying 4.6% and 3.5% of participants, respectively.
Conclusions:
- Bilateral arm BP measurement, prioritizing the higher reading, is crucial for accurate hypertension diagnosis.
- Higher arm BP measurements enhance the predictive accuracy of cardiovascular risk assessment tools.
- Adopting higher arm BP readings in clinical practice is recommended for improved patient management and outcomes.
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.
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