BP and Non-Invasive Vascular Assessments
We provide vascular CVD risk monitoring by measuring, central and not just peripheral arterial stiffness. In particular Pulse Wave Velocity (PWV) is also provided noting some providers only offer (PWA). PWV provides better risk prediction for CVD disease progression than PWA. This can be complemented by 24 hour central ambulatory blood pressure - using “gold standard” devices, especially useful for checking therapeutic intervention on the effects of orthostatic hypotension and nocturnal dipping of BP.
Protect pressure sensitive organs
1.
SphygmoCor® Xcel
SphygmoCor® technology is used clinically for central arterial pressure waveform analysis to better inform blood pressure management. The SphygmoCor system helps physicians individualize care for patients with hypertension, renal disease, COPD, diabetes, and heart failure, among other diseases and conditions. This is the “gold standard” device used by health professionals globally.
It measures central BP variables and Mean Arterial Pressure (MAP) along with Pulse Wave Velocity (PWV) and Augmentation Index (Aix) standardised to a heart rate of 75 beats. In addition it provides The subendocardial viability ratio (SEVR), also known as the Buckberg index, is an arterial stiffness parameter correlated with coronary flow reserve which makes it a useful parameter in assessing coronary microvascular circulation SEVR estimates it is a measure of the balance between cardiac blood flow supply and demand [9].
2.
Lumify Ultrasound to Measure Peripheral PWV
Ultrasound capabilities using the Philips Lumify brings powerful diagnostic capabilities to clinicians. This allows us to image musculoskeletal structures of interest to identify soft tissue injuries and also peripheral blood flow (PWV) via pulsed wave Doppler technology.
Primarily the technology can be used to accurately measure peripheral arterial stiffness which can provide and indication of Peripheral Arterial Disease (PAD) early detection can limit painful claudication as we age.
We can also use it to check central carotid PWV and compare both it and the SphygmoCor for absolute piece of mind about relative risks. We send images of the findings to you other health professionals on your request.
We note that the site of measurement in central BP is important; a meta-analysis has found a difference in the Relative Risk of CVD endpoints if central pulse waveform recording site is Carotid artery (n= 498) 1.48 (CI: 0.86, 2.55)or Radial artery(n= 48561) 1.07 (CI; 1.03, 1.11). - (Li et al., 2024).
CVD endpoint = cardiovascular mortality, myocardial infarction, stroke, heart failure, and revascularisations (coronary artery bypass graft surgery or percutaneous coronary interventions)
3.
24 hr Ambulatory Blood Pressure and Pulse Wave
The Oscar 2™ Ambulatory Blood Pressure Monitor with SphygmoCor® inside is the gold standard in 24-hour ambulatory blood pressure monitoring (ABPM). The Oscar 2 ABP Monitor is independently tested to meet the accuracy and performance requirements of the British Hypertension Society, the European Society of Hypertension International and the AAMI-SP10 standards. Validated to inter-arterial catheter with over 800 published studies.. Because a single or duplicate BP measure is only a snap shot of perhaps true BP which is also influenced by activities of daily living, walking, gardening, sport. An Ambulatory BP taken 14 daytime and 7 nocturnal measures to measure true variation and includes an often missed morning surge as patients wake or an end-of-day spike as the pressures of the day coalesce.
This device also measures Augmentation Index which provides longitudinal info on artery stiffness - as well as central BP a reduction of central pressure may add to reduction of brachial pressure in improving clinical outcome in the treatment of hypertension. From the Anglo-Cardiff Collaborative Trial II (n= ~6700) - There was substantial overlap of aortic systolic pressures between individuals with normal or high normal pressures and those with Stage 1 hypertension based on brachial systolic pressure, indicating that central systolic pressure cannot be inferred from brachial systolic pressure in apparently healthy patients. Central SBP is strongly associated with hypertension‐mediated organ damage (McEniery et al., 2014; Rahman et al., 2018).
Augmentation Pressure: Central systolic and pulse pressures are increased in the presence of stiffer arteries [1][2][3], causing a higher ventricular after-load and energy used by the heart to pump blood around the circulatory system. Evaluation of the central pressure waveform contour allows for determination of augmentation pressure (AP) and the augmentation index (AIx), two parameters that quantify the increased pressure.
Why Measure Central Blood Pressure ?
Noninvasive central blood pressure assessments individualize treatment decisions and help get patients to their health goals faster.
Hypertension management using central BP can produce similar outcomes to therapeutic intervention but with less medication required.[4][5]
Antihypertensive medications have differential effects on central vs. brachial blood pressure, which can explain variability in clinical outcomes.[6]
Central blood pressure is more predictive of cardiovascular (CV) outcomes than brachial blood pressure, primarily due to proximity to target organs.[7]
A Better Predictor of CV Events
A better predictor of outcome: A multi-year, NIH study in more than 3,500 high risk subjects demonstrated that central pulse pressure was more strongly predictive of CV events. Specifically, central pulse pressures > 50mmHG had a 20% increased risk of having a CV event in the next 5 years. Brachial pulse pressure did not show a similar threshold.[7].
24-hour Central Blood Pressure: Oscar 2 with SphygmoCor combines the superior predictive power of Central Blood Pressure with the established standard for hypertension diagnosis providing a 24-hour study with up to 250 brachial and central blood pressure measurements.
For Cardiac Rehabilitation it is noted by Aslanger er al., 2017 that some measures may be needed to be undertaken before CR to optimise exercise induced improvement adjusting baseline supply–demand ratio. These may include reducing afterload by decreasing peripheral vascular resistance and wave reflections (e.g., peripheral vasodilators) or augmenting diastolic blood flow by increasing duration of the diastole (e.g., ivabradine).
References:
O’Rourke et al. Br J Clin Pharmacol 2001;51:507-22
Sharman JE et al J Hum Hypertens 2008 (12):838-44
McEniery et al Hypertension 2008 6(51):1476-82
Sharman et al. Hypertension. 2013 62:1138-45
Kosmala et al. Am J Hypertens. 2015 108
Williams B et al., Circulation 2006 113: 1213-25
Roman, et al., JACC 2009 54:1730-4
London GM Hypertension 2001 38:434-8
Aslanger, E., et al., 2017 Anatolian journal of cardiology, 17(1), 37-43