Brachial cuff blood pressure (BP) accuracy could be influenced by variability in central-to-peripheral systolic BP (SBP)-amplification. However, this has never been determined and we aimed to achieve this by characterising SBP-amplification phenotypes and examining associations with cuff BP accuracy.Design and Method:
Intra-arterial BP was measured at the ascending aorta, brachial and radial arteries in 86 patients (61.6 ± 9.8 years; 66% male) following coronary angiography. Cuff BP was measured bilaterally by oscillometric devices before catheterisation, and then simultaneously with intra-arterial brachial BP. SBP-amplification between arterial segments was defined as ≥5 mmHg SBP increase between the aorta-to-brachial or brachial-to-radial arteries.Results:
Average aortic-to-brachial and brachial-to-radial SBP-amplification were 8.3 ± 9.5 mmHg and 6.4 ± 9.1 mmHg. Four distinct SBP-amplification phenotypes were observed: 1) both aortic-to-brachial and brachial-to-radial SBP-amplification; 2) only aortic-to-brachial SBP-amplification; 3) only brachial-to-radial SBP-amplification; 4) no aortic-to-brachial or brachial-to-radial SBP-amplification. Patients with no SBP-amplification had significantly elevated aortic SBP compared with all other phenotypes (Table, p = 0.037). When measured simultaneously, aortic SBP was significantly underestimated by brachial cuff BP only in the patients with no SBP-amplification (Table 1), despite no differences between phenotypes in clinical characteristics or cuff SBP measured before or simultaneous to catheterisation (p > 0.1 all).Conclusions:
These are the first data to describe distinctive variability in central-to-peripheral SBP-amplification, and includes discovery of a phenotype in which cardiovascular risk may be elevated because of significantly increased aortic SBP that is not detected by conventional cuff BP methods.