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 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 +/- 8 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 +/- 17, 122 +/- 14, 127 +/- 19 mmHg, P = 0.19) but different aortic SBP (133 +/- 21, 120 +/- 16, 112 +/- 18 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 +/- 8.2 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.

Automated summary

The study examined the impact of cuff-to-intraarterial brachial SBP mismatch on hypertension treatment and accuracy towards central SBP. The results showed that there is a significant proportion of patients with inaccurate cuff-based BP measurements, which can lead to mismanagement of blood pressure and inaccurate determination of central BP. The study highlights the need to improve the accuracy of cuff-based BP monitors.