The association between sex and both brachial cuff accuracy and non-invasive central BP estimation remains unclear, and as such, a team of scientists’ primary aim was to investigate whether sex is associated with the accuracy of non-invasive BP measurements with regard to the invasively measured aortic BP.
The secondary objectives were to characterise the determinants of brachial cuff accuracy and to quantify their association with sex.
The invasive BP study cohort comprised patients with a clinical indication for coronary angiography at the Hôpital du Sacré-Coeur de Montréal in Quebec, Canada, and all included participants (n = 500) were without severe aortic stenosis or atrial fibrillation. Invasive aortic BP and cuff-based non-invasive brachial and central BP measurements were recorded simultaneously in all participants.
When feasible, invasive brachial artery BP was also measured. Reasons for non-measurement of invasive brachial BP were related to the procedure (femoral access or safety and time constraints). Race was self-reported by participant and was included to assess generalisability of the findings. Of those patients, the researchers selected a subgroup without significant interarm SBP difference (>5 mm Hg, measured sequentially)
Study details
Accuracy Difference of Noninvasive Blood Pressure Measurements by Sex and Height
Yasmine Abbaoui, Catherine Fortier, Louis-Charles Desbiens, et al
Published in JAMA Network Open on 22 June 2022
Key Points
Question Do noninvasive brachial cuff blood pressure (BP) measurements accurately estimate the invasive aortic (or true) BP in men and women?
Findings In this cross-sectional study of 500 patients undergoing cardiac catheterisation at a tertiary care academic hospital, women had significantly higher invasively measured aortic systolic BP (SBP) compared with men with similar brachial cuff SBP. This disparity was mostly explained by a difference in height, with shorter height associated with greater underestimation of the invasive aortic SBP by the brachial cuff.
Meaning These findings suggest that brachial cuff BP may significantly underestimate true aortic SBP in women, which may lead to unrecognised undertreatment of women compared with men and could partly explain why women are at higher risk of cardiovascular diseases for a given brachial cuff BP.
Abstract
Importance
Women are at higher risk of cardiovascular events than men with similar blood pressure (BP). Whether this discrepancy in risk is associated with the accuracy of brachial cuff BP measurements is unknown.
Objectives
To examine the difference in brachial cuff BP accuracy in men and women compared with invasively measured aortic BP and to evaluate whether noninvasive central BP estimation varies with sex.
Design, Setting, and Participants
This cross-sectional study enrolled 500 participants without severe aortic stenosis or atrial fibrillation from January 1 to December 31, 2019, who were undergoing nonurgent coronary angiography at a tertiary care academic hospital.
Exposures
Simultaneous measurements of invasive aortic BP and noninvasive BP.
Main Outcomes and Measures
Sex differences in accuracy were determined by calculating the mean difference between the noninvasive measurements (brachial and noninvasive central BP) and the invasive aortic BP (reference). Linear regression and mediation analyses were performed to identify mediators between sex and brachial cuff accuracy.
Results
This study included 500 participants (145 female [29%] and 355 male [71%]; 471 [94%] White; mean [SD] age, 66 [10] years). Baseline characteristics were similar for both sexes apart from body habitus. Despite similar brachial cuff systolic BP (SBP) (mean [SD], 124.5 [17.7] mm Hg in women vs 124.4 [16.4] in men; P = .97), invasive aortic SBP was higher in women (mean [SD], 130.9 [21.7] in women vs 124.7 [20.1] mm Hg in men; P < .001). The brachial cuff was relatively accurate compared with invasive aortic SBP estimation in men (mean [SD] difference, −0.3 [11.7] mm Hg) but not in women (mean [SD] difference, −6.5 [12.1] mm Hg). Noninvasive central SBP (calibrated for mean and diastolic BP) was more accurate in women (mean [SD] difference, 0.6 [15.3] mm Hg) than in men (mean [SD] difference, 8.3 [14.2] mm Hg). This association of sex with accuracy was mostly mediated by height (3.4 mm Hg; 95% CI, 1.1-5.6 mm Hg; 55% mediation).
Conclusions and Relevance
In this cross-sectional study, women had higher true aortic SBP than men with similar brachial cuff SBP, an association that was mostly mediated by a shorter stature. This difference in BP measurement may lead to unrecognised undertreatment of women and could partly explain why women are at greater risk for cardiovascular diseases for a given brachial cuff BP than men. These findings may justify the need to study sex-specific BP targets or integration of sex-specific parameters in BP estimation algorithms.
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