Aortic pressure explained

Central aortic blood pressure (CAP or CASP) is the blood pressure at the root of aorta. Studies have shown the importance of central aortic pressure, especially as compared to peripheral blood pressure, and its implications in assessing the efficacy of antihypertensive treatment with respect to cardiovascular risk factors, kidney disease, and mortality. There is an emerging movement for clinicians to begin using central aortic blood pressure, instead of peripheral blood pressure, as a guide for clinical decisions.^[1]

Measurement

In the past, central aortic blood pressure could only be measured by invasive means, such as heart catheterization, but there now exist, or are in late stages of development, noninvasive methods of accurately measuring it indirectly.^{[2] [3] [4]}

Relationship to disease

Elevated central aortic blood pressure has generally been found to be a greater predictor of cardiovascular disease-related mortality, structural changes in the heart, and chronic kidney disease than elevated peripheral blood pressure (such as measured in the brachial artery, the main artery in the upper arm where blood pressure is most commonly measured).^{[5] [6] [7]}

Different medications for lowering blood pressure have different effects on the central aortic pressure and blood flow characteristics, despite producing similar peripheral blood pressure readings. The traditional method of measuring blood pressure in peripheral arteries, such as the brachial artery (the main artery in the upper arm) has been shown to underestimate the efficacy of medications such as amlodipine (a calcium channel blocker) and overestimate the efficacy of those like atenolol (a beta blocker).^[7]

Central aortic blood pressure is a better independent predictor of negative cardiovascular (such as heart attack or stroke) and kidney (such as chronic kidney disease) outcomes than is peripheral blood pressure.^{[7] [8] [9]}

Further reading

• CAFE - The Conduit Artery Functional Endpoint Study
• Lehmann ED . Where is the evidence that radial artery tonometry can be used with a generalised transfer function to accurately and non-invasively predict central aortic blood pressure? . Journal of Human Hypertension . 15 . 2 . 145–6 . February 2001 . 11317196 . 10.1038/sj.jhh.1001126.
• Williams B, Lacy PS, Thom SM . Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes: principal results of the Conduit Artery Function Evaluation (CAFE) study . Circulation . 113 . 9 . 1213–25 . March 2006 . 16476843 . 10.1161/CIRCULATIONAHA.105.595496. etal. free .
• Roman MJ, Devereux RB, Kizer JR . Central pressure more strongly relates to vascular disease and outcome than does brachial pressure: the Strong Heart Study . Hypertension . 50 . 1 . 197–203 . July 2007 . 17485598 . 10.1161/HYPERTENSIONAHA.107.089078. etal. 10.1.1.486.1588 .
• McGhee BH, Bridges EJ . Monitoring arterial blood pressure: what you may not know . Critical Care Nurse . 22 . 2 . 60–4, 66–70, 73 passim . April 2002 . 11961944 .

Notes and References

1. Middeke . Martin . Zentraler aortaler Blutdruck: Bedeutender Parameter für Diagnostik und Therapie . Deutsche Medizinische Wochenschrift . Georg Thieme Verlag KG . 142 . 19 . 2017 . 0012-0472 . 10.1055/s-0043-113212 . 1430–1436 . de.
2. O’Rourke . Michael F. . Adji . Audrey . Noninvasive Studies of Central Aortic Pressure . Current Hypertension Reports . Springer Science and Business Media LLC . 14 . 1 . 15 Nov 2011 . 1522-6417 . 10.1007/s11906-011-0236-5 . 8–20.
3. Liu . Wenyan . Du . Shuo . Zhou . Shuran . Mei . Tiemin . Zhang . Yuelan . Sun . Guozhe . Song . Shuang . Xu . Lisheng . Yao . Yudong . Greenwald . Stephen E. . Noninvasive estimation of aortic pressure waveform based on simplified Kalman filter and dual peripheral artery pressure waveforms . Computer Methods and Programs in Biomedicine . Elsevier BV . 219 . 2022 . 0169-2607 . 10.1016/j.cmpb.2022.106760 . 106760.
4. Mariscal-Harana . Jorge . Charlton . Peter H. . Vennin . Samuel . Aramburu . Jorge . Florkow . Mateusz Cezary . van Engelen . Arna . Schneider . Torben . de Bliek . Hubrecht . Ruijsink . Bram . Valverde . Israel . Beerbaum . Philipp . Grotenhuis . Heynric . Charakida . Marietta . Chowienczyk . Phil . Sherwin . Spencer J. . Alastruey . Jordi . Estimating central blood pressure from aortic flow: development and assessment of algorithms . American Journal of Physiology. Heart and Circulatory Physiology . American Physiological Society . 320 . 2 . 1 Feb 2021 . 0363-6135 . 10.1152/ajpheart.00241.2020 . H494–H510. 10261/265391 . free .
5. Kesten . Steven . Qasem . Ahmad . Avolio . Alberto . Viewpoint: The Case for Non-Invasive Central Aortic Pressure Monitoring in the Management of Hypertension . Artery Research . 28 . 4 . 2022-10-20 . 1876-4401 . 10.1007/s44200-022-00023-z . 128–139. free .
6. Avolio . Alberto . Central Aortic Blood Pressure and Cardiovascular Risk: A Paradigm Shift? . Hypertension . 51 . 6 . 2008 . 0194-911X . 10.1161/HYPERTENSIONAHA.107.108910 . 1470–1471.
7. McEniery . Carmel M. . Cockcroft . John R. . Roman . Mary J. . Franklin . Stanley S. . Wilkinson . Ian B. . Central blood pressure: current evidence and clinical importance . European Heart Journal . Oxford University Press (OUP) . 35 . 26 . 23 Jan 2014 . 1522-9645 . 10.1093/eurheartj/eht565 . 1719–1725. 4155427 .
8. Williams B, Lacy PS, Thom SM . Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes: principal results of the Conduit Artery Function Evaluation (CAFE) study . Circulation . 113 . 9 . 1213–25 . March 2006 . 16476843 . 10.1161/CIRCULATIONAHA.105.595496 . etal. free.
9. 2006 . Benefits of Older Blood Pressure Drugs May be Overestimated While Benefits of Newer Drugs are Underestimated . University of Leicester .