Cuff-based central blood pressure devices systematically overestimated systolic blood pressure amplification at lower levels and underestimated it at higher levels compared to invasive measurements.
Cross-Sectional (n=223)
No
Does cuff-based SBP amplification measurement agree with invasive SBP amplification measurement in patients undergoing coronary angiography?
Cuff-based estimates of SBP amplification show proportional systematic bias and less individual variability compared to invasive measurements, highlighting areas for improving non-invasive central BP devices.
Effect estimate: MD 4 mmHg (95% CI -12 to +20)
p-value: p=<0.001
OBJECTIVE: Accurate measurement of central blood pressure (BP) using upper arm cuff-based methods is associated with several factors, including determining the level of systolic BP (SBP) amplification. This study aimed to determine the agreement between cuff-based and invasively measured SBP amplification. METHODS: Patients undergoing coronary angiography had invasive SBP amplification (brachial SBP - central SBP) measured simultaneously with cuff-based SBP amplification using a commercially available central BP device (device 1: Sphygmocor Xcel; n = 171, 70% men, 60 ± 10 years) and a now superseded model of a central BP device (device 2: Uscom BP+; n = 52, 83% men, 62 ± 10 years). RESULTS: Mean difference (±2SD, limits of agreement) between cuff-based and invasive SBP amplification was 4 mmHg (-12, +20 mmHg, P < 0.001) for device 1 and -2 mmHg (-14, +10 mmHg, P = 0.10) for device 2. Both devices systematically overestimated SBP amplification at lower levels and underestimated at higher levels of invasive SBP amplification, but with stronger bias for device 1 (r = -0.68 vs. r = -0.52; Z = 2.72; P = 0.008). Concordance of cuff-based and invasive SBP amplification across quartiles of invasive SBP amplification was low, particularly in the lowest and highest quartiles. The root mean square errors from regression between cuff-based central SBP and brachial SBP were significantly lower (indicating less variability) than from invasive regression models (P < 0.001). CONCLUSIONS: Irrespective of the difference from invasive measurements, cuff-based estimates of SBP amplification showed evidence of proportional systematic bias and had less individual variability. These observations could provide insights on how to improve the performance of cuff-based central BP.
Bui et al. (Tue,) conducted a cross-sectional in Patients undergoing coronary angiography (n=223). Cuff-based central BP devices (Sphygmocor Xcel and Uscom BP+) vs. Invasive intra-arterial measurement was evaluated on Mean difference between cuff-based and invasive SBP amplification (Device 1) (MD 4 mmHg, 95% CI -12 to +20, p=<0.001). Cuff-based central blood pressure devices systematically overestimated systolic blood pressure amplification at lower levels and underestimated it at higher levels compared to invasive measurements.