Schultz, MG and Picone, DS and Armstrong, MK and Black, JA and Dwyer, N and Roberts-Thomson, P and Sturgess, D and Sharman, JE, The influence of SBP amplification on the accuracy of form-factor-derived mean arterial pressure, Journal of Hypertension, 38, (6) pp. 1033-1039. ISSN 0263-6352 (2020) [Refereed Article]
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Methods: One hundred and eighty-eight patients (69% men, age 60 ± 10 years) undergoing coronary angiography had intra-arterial pressure measured in the ascending aorta, brachial and radial arteries. Reference MAP was measured by waveform integration, and form-factor-derived MAP using 33 and 40% form-factors.
Results: Reference MAP decreased from the aorta to the brachial (-0.7 ± 4.2 mmHg) and radial artery (-1.7 ± 4.8 mmHg), whereas form-factor-derived MAP increased (33% form-factor 1.1 ± 4.2 and 1.7 ± 4.7 mmHg; 40% form-factor 0.9 ± 4.8 and 1.4 ± 5.4 mmHg, respectively). Form-factor-derived MAP was significantly different to reference aortic MAP (33% form-factor -2.5 ± 4.6 and -1.6 ± 5.8, P < 0.001; 40% form-factor 2.5 ± 5.0 and 3.9 ± 6.4 mmHg, P < 0.001, brachial and radial arteries, respectively), with significant variation in the brachial form-factor required (FFreq) to generate MAP equivalent to reference aortic MAP (FFreq range 20-57% brachial; 17-74% radial). Aortic-to-brachial SBP amplification was strongly related to brachial FFreq (r = -0.695, P < 0.001). The 33% form-factor was most accurate with high aortic-to-brachial SBP amplification (33% form-factor MAP vs. reference aortic MAP difference 0.06 ± 3.93 mmHg, P = 0.89) but overestimated reference aortic MAP with low aortic-to-brachial SBP amplification (+5.8 ± 4.6 mmHg, P < 0.001). The opposite was observed for the 40% form-factor.
Conclusion: Due to variable SBP amplification, estimating MAP via form-factors produces nonphysiological inaccurate values. These findings have important implications for accurate assessment of MAP in research and clinical settings.
|Item Type:||Refereed Article|
|Keywords:||amplification, artery, blood pressure, haemodynamic monitoring, homeostasis|
|Research Division:||Biomedical and Clinical Sciences|
|Research Group:||Cardiovascular medicine and haematology|
|Research Field:||Cardiology (incl. cardiovascular diseases)|
|Objective Group:||Clinical health|
|Objective Field:||Clinical health not elsewhere classified|
|UTAS Author:||Schultz, MG (Dr Martin Schultz)|
|UTAS Author:||Picone, DS (Dr Dean Picone)|
|UTAS Author:||Armstrong, MK (Mr Matthew Armstrong)|
|UTAS Author:||Black, JA (Dr Andrew Black)|
|UTAS Author:||Dwyer, N (Dr Nathan Dwyer)|
|UTAS Author:||Roberts-Thomson, P (Dr Philip Roberts-Thomson)|
|UTAS Author:||Sharman, JE (Professor James Sharman)|
|Web of Science® Times Cited:||6|
|Deposited By:||Menzies Institute for Medical Research|
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