Accuracy Difference of Noninvasive Blood Pressure Measurements by Sex and Height.

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 unrecognized 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.

Inaccuracy of brachial blood pressure and its potential impact on treatment and aortic blood pressure estimation.

OBJECTIVE: Although brachial cuff SBP is universally used to guide hypertension management, it can differ significantly from intraarterial SBP. We examine the potential impacts of cuff-to-intraarterial brachial SBP (bSBP) mismatch on hypertension treatment and accuracy towards central SBP. METHODS: In 303 individuals, cuff bSBP (CUFF-bSBP) and central SBP were measured using a Mobil-o-Graph simultaneously to intraarterial bSBP (IA-bSBP) and aortic SBP. According to the difference between CUFF-bSBP and IA-bSBP, we identified three phenotypes: Underestimation (CUFF-bSBP < IA-bSBP by >10 mmHg); No Mismatch (CUFF-bSBP within 10 mmHg of IA-bSBP); Overestimation (CUFF-bSBP > IA-bSBP by >10 mmHg) phenotypes. Risk of overtreatment and undertreatment, and accuracy (ARTERY society criteria: mean difference ≤5 ±â€Š8 mmHg) were determined. A multiple linear regression model was used to assess variables associated with the bSBP difference. RESULTS: Underestimation (n = 142), No Mismatch (n = 136) and Overestimation (n = 25) phenotypes had relatively similar characteristics and CUFF-bSBP (124 ±â€Š17, 122 ±â€Š14, 127 ±â€Š19 mmHg, P = 0.19) but different aortic SBP (133 ±â€Š21, 120 ±â€Š16, 112 ±â€Š18 mmHg, P < 0.001). In the underestimation phenotype, 59% were at risk of undertreatment (14% in No Mismatch), whereas 50% in the Overestimation phenotype were at risk of overtreatment (17% in No Mismatch). CUFF-bSBP accurately estimated aortic SBP only in the No Mismatch Group (mean difference 1.6 ±â€Š8.2 mmHg) whereas central BP never met the accuracy criteria. Male sex, higher height and active smoking were associated with lesser underestimation of bSBP difference. CONCLUSION: The brachial cuff lacks accuracy towards intraarterial BP in a significant proportion of patients, potentially leading to increased risks of BP mismanagement and inaccurate determination of central BP. This illustrates the need to improve the accuracy of cuff-based BP monitors.

Left Atrial Volume and Mortality in Patients With Aortic Stenosis.

BACKGROUND: Left atrium (LA) enlargement is common in patients with aortic stenosis (AS), yet its prognostic implications are unclear. This study investigates the value of left atrial volume (LAV) and LAV normalized to body size for predicting mortality in AS. METHODS AND RESULTS: We included 1351 patients with AS in sinus rhythm at diagnosis and analyzed the occurrence of all-cause death during follow-up with medical and surgical management. Five parameters of LA enlargement were tested: nonindexed LAV and normalized LAV by ratiometric (LAV/body surface area [BSA] and LAV/height) and allometric (LAV/BSA1.7 and LAV/height2.0) scaling. For each parameter, patients in the highest quartile were at high risk of death, whereas outcome was better and similar for the other quartiles. Five-year survival was lower for patients with LAV >95 mL and LAV/BSA >50 mL/m2 compared with those with no or mild LA enlargement (both P<0.001). After adjustment for established outcome predictors, including surgery, high risk of death was observed with LAV >95 mL (adjusted hazard ratio, 1.40 [95% confidence interval, 1.06-1.88]) and LAV/BSA >50 mL/m2 (adjusted hazard ratio, 1.42 [95% confidence interval, 1.08-1.91]). LAV/BSA and LAV showed good and similar predictive performance, whereas other scaling methods did not show better outcome prediction. In patients with severe AS at baseline, preserved (≥50%) ejection fraction, and no or minimal symptoms, LA enlargement was significantly associated with mortality (adjusted hazard ratio, 1.87 [95% confidence interval, 1.02-3.44] for LAV >95 mL, and adjusted hazard ratio, 1.90 [95% confidence interval, 1.03-3.56] for LAV/BSA >50 mL/m2). CONCLUSIONS: LA enlargement is an important predictor of mortality in AS, incrementally to known predictors of outcome. LAV and LAV/BSA have comparable predictive performance and should be assessed in clinical practice for risk stratification.

Impact of Mean Transaortic Pressure Gradient on Long-Term Outcome in Patients With Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction.

BACKGROUND: Mean transaortic pressure gradient (MTPG) has never been validated as a predictor of mortality in patients with severe aortic stenosis. We sought to determine the value of MTPG to predict mortality in a large prospective cohort of severe aortic stenosis patients with preserved left ventricular ejection fraction and to investigate the cutoff of 60 mm Hg, proposed in American guidelines. METHODS AND RESULTS: A total of 1143 patients with severe aortic stenosis defined by aortic valve area ≤1 cm2 and MTPG ≥40 mm Hg were included. The population was divided into 3 groups according to MTPG: between 40 and 49 mm Hg, between 50 and 59 mm Hg, and ≥60 mm Hg. The end point was all-cause mortality. MTPG was ≥60 mm Hg in 392 patients. Patients with MTPG ≥60 mm Hg had a significantly increase risk of mortality compared with patients with MTPG <60 mm Hg (hazard ratio [HR]=1.62 [1.27-2.05] P<0.001), even for the subgroup of asymptomatic or minimally symptomatic patients (HR=1.56 [1.04-2.34] P=0.032). After adjustment for established outcome predictors, patients with MTPG ≥60 mm Hg had a significantly higher risk of mortality than patients with MTPG <60 mm Hg (HR=1.71 [1.33-2.20] P<0.001), even after adjusting for surgery as a time-dependent variable (HR=1.71 [1.43-2.11] P<0.001). Similar results were observed for the subgroup of asymptomatic or minimally symptomatic patients (HR=1.70 [1.10-2.32] P=0.018 and HR=1.68 [1.20-2.36] P=0.003, respectively). CONCLUSIONS: This study shows the negative prognostic impact of high MTPG (≥60 mm Hg), on long-term outcome of patients with severe aortic stenosis with preserved left ventricular ejection fraction, irrespective of symptoms.