Central blood pressure: current evidence and clinical importance
Carmel M. McEniery1*, John R. Cockcroft2, Mary J. Roman3,
Stanley S. Franklin4, and Ian B.Wilkinson1
1Clinical
Pharmacology Unit, University of Cambridge, Addenbrooke’s
Hospital, Box 110, Cambridge CB22QQ, UK; 2Department of Cardiology,Wales Heart Research Institute,
Cardiff
CF14 4XN, UK; 3Division
of Cardiology,Weill Cornell Medical College, New York, NY 10021, USA; and 4University of California, UCI School of
Medicine, Irvine, CA 92697-4101, USA
Received 29 April 2013;
revised 27 November 2013; accepted 17 December 2013; online
publish-ahead-of-print 23 January 2014
and central pressure. Therefore, basing treatment decisions on central,
rather than brachial pressure, is likely to have important implications
for the future diagnosis and management of hypertension. Such a paradigm
shift will, however, require further, direct evidence that selectively
targeting central pressure, brings added benefit, over and above that
already provided by brachial artery pressure.
Central pressure † Blood pressure † Anti-hypertensive treatment † Cardiovascular risk
Introduction
The brachial cuff sphygmomanometer was introduced into medicalpractice well over 100 years ago, enabling the routine, non-invasive,
measurement of arterial blood pressure. Life insurance companieswere among the first to capitalize on the information provided by
cuff sphygmomanometry, by observing that blood pressure inlargely asymptomatic individuals relates to future cardiovascular
risk—observations that are nowsupported by a wealth of
epidemiologicaldata.1 The most recent Global Burden
of Disease report2
identified hypertension as the leading cause of death and disabilityworldwide. Moreover, data from over 50 years of randomized controlled
trials clearly demonstrate that lowering brachial pressure,in hypertensive individuals, substantially reduces cardiovascular
events.1,3 For these reasons, measurement of brachial blood pressurehas become embedded in routine clinical assessment throughout
thedeveloped world, and is one of the most widely accepted ‘surrogatemeasures’ for regulatory bodies.
The major driving force for the continued use of brachial bloodpressure has been its ease of measurement, and the wide variety of
devices available for clinical use. However, we have known for overhalf a century that brachial pressure is a poor surrogate for aortic
pressure, which is invariably lower than corresponding brachialvalues. Recent evidence suggests that central pressure is also more
strongly related to future cardiovascular events4 – 7 than brachialpressure, and responds differently to certain drugs.8,9 Appreciating
this provides an ideal framework for understanding the much publicizedinferiority of atenolol and some other beta-blockers,10 compared
with other drug classes, in the management of essentialhypertension. Although central pressure can now be assessed noninvasively
with the same ease as brachial pressure, clinicians are unlikelyto discard the brachial cuff sphygmomanometer without
robust evidence that cardiovascular risk stratification, and monitoringresponse to therapy, are better when based on central rather
than peripheral pressure. Central pressure assessment and accuracywill also have to be standardized, as it has been for brachial pressure
assessment with oscillometric devices. This review will discuss ourcurrent understanding about central pressure and the evidence
required to bring blood pressure measurement, and cardiovascularrisk assessment into the modern era.
Physiological concepts
Arterial pressure varies continuously over the cardiac cycle, but inclinical practice only systolic and diastolic pressures are routinely
reported. These are invariably measured in the brachial arteryusing cuff sphygmomanometry—a practice that has changed
little
over the last century. However, the shape of the pressure waveform* Corresponding
author. Tel: +44 1223 336806, Fax: +44 1223 216893, Email: cmm41@cam.ac.uk
Published on behalf of the European Society of Cardiology. All rights
reserved. &The Author 2014. For
permissions please email: journals.permissions@oup.com
European Heart Journal (2014) 35, 1719–1725 doi:10.1093/eurheartj/eht565
Pressure measured with a cuff and sphygmomanometer in the brachial artery
is accepted as an important predictor of future cardiovascular risk.
However, systolic pressure varies throughout the arterial tree, such that
aortic (central) systolic pressure is actually lower than corresponding
brachial values, although
this difference is highly variable between individuals. Emerging evidence now
suggests that central pressure is better
related to
future cardiovascular events than is brachial pressure. Moreover, anti-hypertensive
drugs can exert differential effects on brachial
and
central pressure. Therefore, basing treatment decisions on central, rather than
brachial pressure, is likely to have important implications
for the future diagnosis and management of hypertension. Such a
paradigm shift will, however, require further, direct evidence that selectively
targeting central pressure, brings added benefit, over and above that already
provided by brachial artery pressure.As discussed earlier,
a full synthesis of the available evidence concerning
central pressure and the risk of future cardiovascular events is now required. However, it will also be necessary to determine
the clinical
relevance of differences between brachial and central pressurefor the individual patient, especially given
the relatively high correlation between the two. Emerging data support the prognostic superiority of both 24-h ambulatory blood pressure monitoring
(ABPM)79 – 81 andhomemonitoring81 in comparison with office measurements. Interestingly, a recent
study82 demonstrated that
24-h ambulatory cuff pressures
were comparable with office central pressure
measurements in the prediction of risk, although the significance of this study awaits
confirmation.83 As yet,
there are no data comparing
the predictive value ofhomemonitoring vs. central
pressure in theprediction of risk. Ultimately, it will be necessary to evaluate
the prognostic value of 24-h ambulatory central pressure.With the recent
development of ambulatory central pressure systems,84,85 this is now
possible and it may be reasonable to hypothesize that 24-h central, rather than brachial ABPM
would be superior in terms of risk prediction.
|
Arterial stiffness The term "arterial
stiffness" once referred only to the
loss of compliance in the large arteries,
now it is a comprehensive term encompassing
the characteristics of the entire arterial
system, including the biochemical-structural-mechanical
changes in the small and large arteries,
as well as the comparative pressures. Cardiovascular
disease is the No. 1 cause of death worldwide.
Heart attack, heart failure and stroke are
the top three within the category. A sudden
jump in blood pressure is the most frequent
cause of stroke, while myocardial infarctions
(heart attacks) are most often caused by
a partial or full coronary occlusion, a rupture
of vulnerable plaque built up during severe
coronary atherosclerosis. In nearly every
case, some stage of the process of sclerosis
is present. In order to prevent severe vascular
crises, it is essential to identify individuals
who are at risk but have not yet developed
symptoms. Identification of at-risk individuals,
examination of the patient for the signs
of preclinical atherosclerosis, as well as
the identification and treatment of the classical
risk factors are included in the European
Guidelines for the management of arterial
hypertension since 2007. "Sudden heart
attack," in the literal sense of the
word, does not exist. The arterial system
prepares for a plaque rupture over the course
of years, or even decades, like a ticking
time bomb. Most severe events can, therefore,
be prevented with early detection of atherosclerosis
(with the help of functional and structural
tests) and preventive treatment begun in
a timely manner. European Guidelines list
the types of target organ damage that can
occur even in asymptomatic patients. The
screening is recommended and mandatory in
every hypertension patient. The Guidelines
emphasize the screening for asymptomatic
atherosclerosis in as large a pool of individuals
as possible, as well as the importance of
such testing for high risk of cardiovascular
disease because together with the traditional
risk factors, it has a greater degree of
predictive value. It is a simple, proven
fact today that arterial stiffness is a truly
important and independent indicator of cardiovascular
risk. The functional and structural changes
in the large arteries are partly age-related,
but there are several conditions that show
a link with accelerated arterial stiffening,
such as hypertension, atherosclerosis, end-stage
renal disease, as well as the traditional
risk factors (diabetes, dyslipidemia, smoking
etc.). That is why arterial stiffness has
become a main topic of clinical research
in recent years, indicated by the huge increase
in publications on the subject. |
Why you should buy an Arteriograph Arteriograph-
Comprehensive cardiovascular risk assessment
in only 3 minutes! - A medical breakthrough
in early diagnostics of atherosclerosis!
A big problem today is that many individuals
with high risk of cardiovascular diseases
otherwise have normal values; normal blood
pressure, blood lipids and resting-EKG. The
catastrophe strikes without any prior warning.
The Arteriograph is an evidence based, fast,
easy, noninvasive and user independent way
of assessing cardiovascular risk. For the
first time one have a good chance of finding
high risk patient before it is too late.
1. Screening of early atherosclerosis among
"healthy" individuals. Only the
Arteriograph is useful for this. The Arteriograph
gives an overall picture of the risk of assessing
cardiovascular disease. 2. Evaluating the
effects of treatments (drugs, nutritional
supplements and lifestyle changes etc) on
the vascular functions among patients with
established atherosclerosis (CAD, POST MI,
STROKE, PAD) 3. Is it not enough to check
the blood lipids and blood pressure to prevent
atherosclerosis and thereby strokes? No,
40-60% of patients with stroke or heart attacks
do not have any know abnormal values such
as high amount of blood lipids or high blood
pressure (Johns Hopkins White Papers, Coronary
Heart Disease - 1998, etc). They also have
normal blood glucose values, resting-EKG,
are non-smokers and have a healthy diet.
Up until now it has been impossible to find
there individuals. 4. Todays metods of assessing
cardiovascular risk (SCORE, Framingham) all
have limits. They do not take into account
important factors such as lack of physical
activity, overweight, psychological factors
or previous cardiovascular circumstances.
(Simon, A. and Levenson, J.: May subclinical
arterial disease helps to better detect and
treat high-risk asymptomatic individuals?
J Hypertension 2005, 23: 1939-1945) 5. In
most cases, lowering the blood pressure is
not enough to avoid early death. Individuals
who can lower both their arterial stiffness
and blood pressure have a much greater chance
of a longer life.Circulation 2001;103:987
6. The Arteriograph is mobile and easy to
use. The screening is fast, comfortable,
harmless and user independent. It takes only
a few minutes and can be described as a computerized
blood pressure measurement. 7. Today´s other
available methods are hard to use, expensive,
and requires an adequate educated staff.
In the future, the Arteriograph may replace
the regular blood pressure measurement as
it is just as easy but gives much more information.
The Arteriograph is intended for DAILY USE
at your clinic to measure AIx, PWV and Central
blood pressure etc. Arteriograph- Comprehensive
cardiovascular risk assessment in only 3
minutes! - A medical breakthrough in early
diagnostics of atherosclerosis! A big problem
today is that many individuals with high
risk of cardiovascular diseases otherwise
have normal values; normal blood pressure,
blood lipids and resting-EKG. The catastrophe
strikes without any prior warning. The Arteriograph
is an evidence based, fast, easy, noninvasive
and user independent way of assessing cardiovascular
risk. For the first time one have a good
chance of finding high risk patients before
it is too late .The Arteriograph is also
used to evaluate the effect of different
medications. Free demonstration of the Arteriograph
on Wednesdays at 5-7 pm at S?derkliniken,
G?tgatan 82. Please call in advance to let
us know that you will be there. |
|
American Journal of Hypertension ajh.oxfordjournals.org
Am J Hypertens (2005) 18 (S4): 15A. doi:
10.1016/j.amjhyper.2005.03.035 P-17: A new
and fast screening method for measuring complex
hemodynamical parameters and arterial stiffness
non-invasively with a simple arm cuff Miklos
Illyes1 + Author Affiliations 1TensioMed
Ltd., TensioMed Ltd, Budapest, Hungary Abstract
Aims: In a project of the National Research
Program of Hungary, we studied if oscillometric
signals received during an oscillometric
BP measurement contain any information about
arterial hemodynamics Materials, Methods:
We have developed a research tool by which
not only SBP, DBP, HR data, but the complete
oscillometric signals were stored and transmitted
telemedically to our computer center from
the home of 650 patients who performed BP
measurements at least 4 times a day, for
at least 1 month. Through this a large database
was collected, containing more than 1700000
oscillometric pulse curves and the relevant
clinical data of patients. For data mining
we used Kohonen's self-organising map method.
Non-invasively recorded oscillometric curves
from the upper arm cuff were validated by
the simultaneously recorded intraarterial
pressure curve of brachial artery. Results:
Our researches showed that oscillometric
pulse curve of the brachial artery is identical
to the intraarterial pressure curve if the
cuff was inflated to suprasystolic pressure,
preferably 35 mmHg above the SBP. Thus the
early and the late systolic pressure peak,
the closing incisure of the aortic valve
can be recognizable, and several hemodinamical
parameters could be calculated. By using
the mentioned results of basic researches,
a new instrument, the TensioClinic Arteriograph
was developed, by which the following parameters
could be measured within 2 minutes, by using
a simple upper arm cuff: SBP, DBP, HR, MAP,
PP, augmentation index (AIx), normalized
augmentation index to 80/min heart rate (AIx80),
return time of the pulse wave of the aorta
(RT), pulse wave velocity (PWV) of the aorta,
length of the cardiac cycle, area of systolic
(SAI) and diastolic (DAI) part of pulse curve.
Validation studies of the new method to control
the accuracy of measured AIx and PWV showed
high correlations (R = 0,76 and R = 0,8)
with values measured with other non-invasive
methods (Sphygmocor and Complior) respectively.
Conclusions: Due to the swiftness, simplicity
and good reproducibility of this method and
apparatus, the non-invasive assessment of
the most important hemodynamical parameters
and arterial stiffness had become available
for population screening, opening a new window
in the detection of the early phase of the
athero- and arteriosclerosis, and thus it
can play an important role in the reduction
of the CV morbidity and mortality. |
Hungary's "tensio arteriograph"
- a simple way of examining our veins 27-01-2006
11:38 | S?ndor Laczk? " Send by email
" Print Cardio-vascular disease is the
leading cause of death in Hungary and much
of the rest of the world. Problems are often
detected too late because many people do
not suffer obvious symptoms. Even suspect
cases can be difficult to confirm. But that
may soon be history thanks to a new device
invented by Hungarian doctor Miklos Illyes.
The "tensio arteriograph" is the
first and so far only device that provides
us with a fast and easy way of obtaining
cardiac data that in the past could only
be obtained through complicated and sometimes
painful screenings. "The medical profession
was lacking a proper method to determine
these data, called 'arterial stiffness parameters',
namely, the augmentation index and the pulse
rate velocity of the human aorta. So, this
method before was determined by very specific
procedures, very difficult methods, which
needed a lot of time and a lot of expert
knowledge of how to perform the examination."
Tensio arteriograph Says, doctor Miklos Illyes,
the inventor of the tensio arteriograph.
So how does it work? It's much simpler than
one might expect. The arteriograph detects
the condition of our veins in a procedure
that's just as easy as taking our blood pressure.
"We discovered a new method how to assess
the so-called arterial stiffness non-invasively
with a very fast method, which needs only
two minutes to determine the arterial age
of the patient. This novelty consists of
the fact that we use a simple cough to determine
important central human dynamical parameters.
This makes it possible for us to use this
method for everyday practice and to screen
the patient for arteriosclerosis. We do feel
that in a few years, this kind of method
will be used generally not only to check
blood pressure but to have much more information
about arterial stiffness beyond blood pressure
measurement." Dr. Laszlo Tisler of the
St. Imre Hospital in Budapest was one of
the first physicians to use it: "My
experience over all is very positive. It
uses a very new way of assessing the compliance
of large blood vessels. This information
is substantial because it is associated with
the survival of our patients - in particular,
with patients of higher cardiovascular risk.
The information this device provides is extremely
helpful in those with high risk, and this
may add new information, information on compliance
of the vessel, or stiffness of the vessel,
may provide information on those who have
no other risk factors and this may be a very
early sign of cardiovascular risk."
|
|
Pulse Wave Analysis The pulse wave reflects
the condition of the entire arterial system,
from the large arteries all the way to the
small arteries. Pulse wave analysis is a
technique recognized long ago, since doctors
in China measured it as part of traditional
medicine, using the three fingers on the
pulse method, and a long road of experience
brought it into scientific knowledge. The
first graphic procedures for registration
of pulse waves were first demonstrated in
Paris (Marey) and then London (Mahomed) in
the last century, then for a smaller audience
of interested parties. 100 years ago, Mahomed
used the sphygmomanometer to show asymptomatic
high blood pressure and to test for chronic
nephritis. In the 20th century with the high-tech
explosion, technologies offering fundamental
and detailed information about the condition
of the entire arterial system were developed,
whose use and analysis is very simple. Thus
the non-invasive pulse wave test is now conducted
with other methods. High-fidelity sensors,
tonometers and piezo-techniques make it possible
to observe and record the pulse wave shape
more and more accurately. The recognition
of changes in pressure makes it easier to
understand hemodynamics and the process of
arterial aging. The pulse wave, depending
on the method, can be felt and registered
in areas where arterial pulsation is easily
accessible. Measurement can be carried out
most easily similarly to blood pressure measurement
with tonometry and piezo-electric technologies
on the carotid, radial and femoral arteries,
and the newest, oscillometric methods on
the upper arm. The direct wave traveling
toward the heart, the reflective wave and
the systolic and diastolic periods can be
determined from the pulse wave contour, and
from this we can draw conclusions regarding
the interaction of the heart and the arterial
system, which until now could only be recognized
using invasive arterial catheterization.
Today, with the help of pulse wave analysis,
we can better familiarize ourselves with
the physiological and pathological behavior
of the arterial wall, and determine a more
exact diagnosis and therapy. Pulse wave amplification
The shape of a blood pressure wave (BP) constantly
distorts as it travels from the central elastic
arteries toward the muscular conduit arteries.
This is a physiological phenomenon, that
the blood pressure, as a periodically oscillating
wave, travels and reflects in occasionally
differently structured portions of the viscoelastic
arterial system. In healthy individuals,
the pulse wave amplitude (pulse pressure
(PP)) increases from the aorta/carotid section
to the brachial/radial section without added
energy, such that the arterial central pressure
and the diastolic pressure remains almost
unchanged. This phenomenon is called pulse
wave amplification, the change in the maximum
systolic blood pressure level in the arterial
system, its increase from the aorta toward
the periphery. More and more clinical research
focuses on the prognostic value of the peripheral
and central systolic blood pressure levels.
Pulse wave amplification can be described
in several different ways, the most well
known being the ratio or difference between
the distal and the proximal maximums. From
a physiological standpoint, in addition to
a given brachial (peripheral) pulse pressure
the most favorable effect on the heart and
arterial system is an even lower central
pressure value, since the heart must thus
work against a lower pulsatile pressure (and
the larger the difference in the absolute
value of the periphery and central pressures,
the more favorable the amplification). Pulse
wave amplification, according to statistics,
decreases with age. In high blood pressure
research and in heart and arterial system
risk assessment the role of central blood
pressure has come to the forefront, and today
it is clear that it is a better marker than
peripheral (upper arm) blood pressure for
the condition of target organ damage and
for cardiovascular risk and therapy. The
conventional, traditional method based on
high blood pressure in quite a number of
cases overestimates or underestimates cardiovascular
risk. Furthermore it has become clear that
the different pharmaceutical groups do not
affect pulse pressure amplification in the
same way; for example, vasodilator agents
increase compared with the beta blockers.
In contrast to brachial blood pressure, pulse
wave amplification in and of itself predicts
CV mortality, and shows a strong correlation
with pulse pressure measured in the carotid
as well - we can read this in a study of
late-stage renal disease patients. Another
publication provides evidence that in untreated
patients suffering from essential high blood
pressure they observed that following therapy
a decrease in left ventricular mass index
directly correlated to an increase in pulse
wave amplification, and not to a decrease
in brachial blood pressure. Benetos et al
first carried out testing at the population
level, in which they proved that PP amplification
in and of itself correlates to cardiovascular
mortality, independent of other risk factors.
|
Renal Denervation Improves Blood Pressure
And Arterial Stiffness Published: August
27, 2012. By European Society of Cardiology
http://www.escardio.org Munich, Germany -
August 27 2012: Renal denervation improves
blood pressure and arterial stiffness in
patients with therapy resistant hypertension,
according to research presented at ESC Congress
2012 by Mr Klaas Franzen from the University
Hospital of Schleswig-Holstein. The findings
suggest that renal denervation regenerates
blood vessels and could reduce cardiovascular
events. Related Content " Go to European
Society of Cardiology's website " Show
More News from European Society of Cardiology
Malignant arterial hypertension was historically
treated with surgical thoracolumbar splanchnicectomy,
a type of sympathectomy treatment that was
introduced in 1938. "A significant reduction
in blood pressure response was observed in
at least half of the patients who underwent
splanchnicectomy," said Mr Franzen.
"But the treatment led to severe adverse
events such as orthostatic hypotension, anhidrosis
and intestinal disturbances. After the discovery
of effective antihypertensive drugs, splanchnicectomy
became neglected and disregarded over time."
In 2009 the concept of sympathectomy was
reintroduced with intravasal catheter-based
percutaneous renal sympathetic denervation
(RDN) used in patients suffering from resistant
arterial hypertension. Recent publications
have shown that RDN significantly lowers
systolic and diastolic peripheral brachial
blood pressure by 32/12 mmHg after 6 months.
Mr Franzen said: "RDN with radiofrequency
energy has several important advantages over
surgical splanchnicectomy: it is a minimally
invasive procedure without significant systematic
side effects, it is well tolerated, and recovery
times are short." Arterial hypertension
can irrevocably harm blood vessels in the
short and long term, subsequently leading
to increased aortic/arterial stiffness and
arteriosclerosis. "Since central aortic
pressures and arterial stiffness are much
better predictors for future cardiovascular
events than peripheral pressures we focused
the present study on the effects of RDN on
central hemodynamics and arterial stiffness,"
said Mr Franzen. The researchers studied
21 patients with therapy resistant hypertension
(61.9% men; mean age 64 years; 5.0±1.3 antihypertensive
drugs) and 6 controls (83.3% men; mean age
57 years; 4.3±2.3 antihypertensive drugs).
The inclusion criteria were: (i) use of >3
antihypertensive drugs, (ii) peripheral blood
pressure at baseline ?150 mmHg, and (iii)
exclusion of secondary hypertension and anatomical
abnormalities of the renal arteries. RDN
was performed with an RDN radiofrequency
ablation catheter system (1). Central hemodynamics
and arterial stiffness, i.e. pulse wave velocity
(PWV), were recorded with an Arteriograph
device (2). Measurements were performed at
baseline, and 3 and 6 months after the intervention.
RDN led to an improvement in all parameters
compared to baseline. Peripheral systolic
blood pressure improved by 7.6% (145 mmHg
versus 156 mmHg, p<0.05) after 3 months
and by 5.4% (148 mmHg versus 156 mmHg, p<0.05)
after 6 months. Central systolic blood pressure
improved by 9.5% (147 mmHg versus 161 mmHg,
p<0.01) after 3 months and by 6.6% (151
mmHg versus 161 mmHg, p<0.05) after 6
months. Most importantly, PWV improved significantly,
both at 3 months (9.4±1.2 m/s versus 10.9±1.8
m/s, p<0.01) and 6 months (9.7±1.8 m/s
versus 10.9±1.8 m/s, p<0.01). Univariate
analysis of variance (f-test) showed that
the improvement of PWV was, at least in part,
blood pressure independent. In controls no
significant changes in blood pressure values
or PWV were observed. "Besides peripheral
blood pressures, RDN improved central blood
pressures and arterial stiffness, i.e. PWV,"
said Mr Franzen. "According to age adjusted
reference values, the improvement of approximately
1m/s PWV observed in our study could be interpreted
as a blood vessel rejuvenation of almost
10 years. This suggests that RDN might be
a fountain of youth for blood vessels in
patients with therapy resistant hypertension."
He added: "Further studies are needed
to determine whether the benefits of RDN
translate into a reduced risk of cardiovascular
events." |
|
Hypertension Research (2011) 34, 202-208;
doi:10.1038/hr.2010.196; published online
21 October 2010 Can arterial stiffness parameters
be measured in the sitting position? Jens
N?rnberger1, Rene Michalski2, Tobias R T?rk2,
Anabelle Opazo Saez1, Oliver Witzke2 and
Andreas Kribben2 1. 1Department of Nephrology
and Dialysis, HELIOS Kliniken Schwerin, Wismarsche
Stra?e, Schwerin, Germany 2. 2Department
of Nephrology, University Hospital Essen,
University Essen-Duisburg, Hufelandstra?e,
Essen, Germany Correspondence: Dr J N?rnberger,
Department of Nephrology, HELIOS Kliniken
Schwerin, Wismarsche Stra?e 393-397, Schwerin
19049, Germany. E-mail: jens.nuernberger@uni-due.de
Received 2 May 2010; Revised 25 July 2010;
Accepted 31 July 2010; Published online 21
October 2010. Top of page Abstract Despite
the introduction of arterial stiffness measurements
in the European recommendation, pulse wave
velocity (PWV) and augmentation index (AI)
are still not used routinely in clinical
practice. It would be of advantage if such
measurements were done in the sitting position
as is done for blood pressure. The aim of
this study was to evaluate whether there
is a difference in stiffness parameters in
sitting vs. supine position. Arterial stiffness
was measured in 24 healthy volunteers and
20 patients with cardiovascular disease using
three different devices: SphygmoCor (Atcor
Medical, Sydney, Australia), Arteriograph
(TensioMed, Budapest, Hungary) and Vascular
Explorer (Enverdis, Jena, Germany). Three
measurements were performed in supine position
followed by three measurements in sitting
position. Methods were compared using correlation
and Bland-Altman analysis. There was a significant
correlation between PWV in supine and sitting
position (Arteriograph: P<0.0001, r=0.93;
Vascular Explorer; P<0.0001, r=0.87).
There were significant correlations between
AI sitting and AI supine using Arteriograph
(P<0.0001, r=0.97), Vascular Explorer
(P<0.0001, r=0.98) and SphygmoCor (P<0.0001,
r=0.96). When analyzed by Bland-Altman, PWV
and AI measurements in supine vs. sitting
showed good agreement. There was no significant
difference in PWV obtained with the three
different devices (Arteriograph 7.5±1.6?m?s?1,
Vascular Explorer 7.3±0.9?m?s?1, SphygmoCor
7.0±1.8?m?s?1). AI was significantly higher
using the Arteriograph (17.6±15.0%) than
Vascular Explorer and SphygmoCor (10.2±15.1%
and 10.3±18.1%, respectively). The close
agreement between sitting and supine measurements
suggests that both PWV and AI can be reliably
measured in the sitting position. Keywords:
arterial stiffness; augmentation index; PWV;
pluse wave velocity |
| Abstracts of the American Society of Hypertension,
Inc. 28th Annual Scientific Meeting and Exposition,
San Francisco, USA May 15-18, 2013 The Journal
of Clinical Hypertension, 2013, Volume 15,
May 2013 Abstract Supplement 28th Annual
Scientific Meeting and Exposition San Francisco,
USA May 15-18, 2013. ________________________________________
Acute Coronary Syndrome Patients: How Stiff
are their Arteries? Deaconu Alexandru Ioan
1 , Tautu Oana Florentina 1 , Fruntelata
Ana Gabriela 2 , Dorobantu Maria 1 1 Emergency
Hospital of Bucharest, Bucharest, Romania;
2 Monza Cardiovascular Center, Bucharest,
Romania Several non-invasive methods are
currently used to assess vascular stiffness.
Pulse wave velocity (PWV) and the augmentation
index (AIx) are the two major non-invasive
methods of assessing arterial stiffness.
A large amount of evidence indicates that
carotid-femoral PWV is an intermediate endpoint
for cardiovascular (CV) events, either fatal
or non-fatal. Central AIx and pulse pressure
have shown an independent predictive value
for CV events in hypertensives and patients
with coronary disease. Studies of arterial
stiffness in patients with cardiovascular
emergencies and acute coronary syndromes,
respectively, are missing. We performed measurements
of arterial stiffness parameters using the
TensioMed Arteriograph in 34 patients admitted
for acute coronary syndromes (ACS), 24 hours
after admission. The study group included
28 males (82.4%) and mean age was 61.7 ±
14.07 years. Arterial stiffness parameters
as aortic PWV, aortic AIx, central systolic
blood pressure (aortic SBP), central pulse
pressure (aortic PP) were analyzed in relation
to clinical, historical and paraclinical
parameters in order to describe particularities
in this patient population. We compared the
results with an age and sex adjusted population
of 34 controls randomly selected from the
most recent Romanian cross-populational statistical
survey, SEPHAR II. In our group, 45.7% of
patients were hypertensive and 37.1% were
diabetic. Most of the patients were on treatment
with ACE inhibitors (91.4%) and beta-blockers
(80%), while 71.1% were on intravenous or
oral nitrates. Mean stiffness parameters
in this group were: aortic AIx=28.51 + 10.81,
with only 14.8% of patients showing normal
values; aortic PWV = 9.71 ± 1.82 m/s; aortic
SBP = 121.71 ± 21.07 mm Hg; aortic PP =
44.39 ± 13.74 mm Hg. No correlations were
identified in this small group between arterial
stiffness parameters and treatment, history
of hypertension or diabetes, type of ACS
and angiographic coronary anatomy. While
aortic AIx was clearly abnormal, reflecting
changes in endothelial function and waves'
reflection, the other parameters of arterial
stiffness were not different from other patient
populations. Aortic AIx is abnormally increased
in patients with acute coronary syndromes.
Parameters of arterial stiffness in patients
with ACS are not related to treatment, type
of coronary disease or previous patient history.
|
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Assessment of arterial stiffness in hypertension:
comparison of oscillometric (Arteriograph),
piezoelectronic (Complior) and tonometric
(SphygmoCor) techniques. Noor A Jatoi, Azra
Mahmud, Kathleen Bennett, John Feely Department
of Pharmacology and Therapeutics, Trinity
College Centre for Health Sciences and Hypertension
Clinic, St. James's Hospital, Dublin, Ireland.
Journal of hypertension (impact factor: 4.02).
10/2009; 27(11):2186-91. DOI:10.1097/HJH.0b013e32833057e8
Source: PubMed ABSTRACT Arterial stiffness,
measured as aortic pulse wave velocity (PWV),
and wave reflection, measured as augmentation
index (AIx), are independent predictors for
total and cardiovascular morbidity and mortality.
The aim of this study was to compare a new
device |
Assessment of arterial stiffness in hypertension:
comparison of oscillometric (Arteriograph),
piezoelectronic (Complior) and tonometric
(SphygmoCor) techniques. Abstract BACKGROUND
Arterial stiffness, measured as aortic pulse
wave velocity (PWV), and wave reflection,
measured as augmentation index (AIx), are
independent predictors for total and cardiovascular
morbidity and mortality. The aim of this
study was to compare a new device, based
on oscillometric pressure curves (Arteriograph),
which simultaneously measures PWV and AIx,
with standard techniques for measuring PWV
(Complior) and AIx (SphygmoCor) in untreated
hypertensive patients. METHODS We compared
PWV and AIx measured using the Arteriograph
with corresponding Complior and SphygmoCor
measurements in 254 untreated hypertensive
patients, age 48 +/- 14 years (mean +/- SD,
range 17-85 years). RESULTS Arteriograph
PWV and AIx were closely related with Complior
(r = 0.60, P < 0.001) and SphygmoCor (r
= 0.89, P < 0.001), respectively. Using
stepwise regression analysis, the independent
determinants of Arteriograph PWV were age,
mean arterial pressure, heart rate and sex
(r(2) = 0.44, P < 0.0001) and for AIx
were age, weight, mean arterial pressure,
heart rate and sex (r(2) = 0.65, P < 0.0001).
The bias between the different techniques
was determined by age and sex for PWV and
age, body weight, sex, heart rate and mean
arterial pressure for AIx. Bland-Altman plots
showed that although the techniques were
closely related, the limits of agreement
were wide. CONCLUSION Although Arteriograph
values and the determinants of PWV and AIx
are in close agreement with corresponding
parameters obtained by Complior and SphygmoCor,
respectively, the techniques are not interchangeable.
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Clin Cardiol. 2012 Jan;35(1):26-31. doi:
10.1002/clc.20999. Epub 2011 Nov 14. Comparison
of aortic and carotid arterial stiffness
parameters in patients with verified coronary
artery disease. Gaszner B, Lenkey Z, Illy?s
M, S?rszegi Z, Horv?th IG, Magyari B, Moln?r
F, K?nyi A, Czir?ki A. Source Heart Institute,
Faculty of Medicine, University of P?cs,
Hungary. Abstract BACKGROUND: Arterial stiffness
parameters are commonly used to determine
the development of atherosclerotic disease.
The independent predictive value of aortic
stiffness has been demonstrated for coronary
events. HYPOTHESIS: The aim of our study
was to compare regional and local arterial
functional parameters measured by 2 different
noninvasive methods in patients with verified
coronary artery disease (CAD). We also compared
and contrasted these stiffness parameters
to the coronary SYNTAX score in patients
who had undergone coronary angiography. METHODS:
In this study, 125 CAD patients were involved,
and similar noninvasive measurements were
performed on 125 healthy subjects. The regional
velocity of the aortic pulse wave (PWVao)
was measured by a novel oscillometric device,
and the common carotid artery was studied
by a Doppler echo-tracking system to determine
the local carotid pulse wave velocity (PWVcar).
The augmentation index (AIx), which varies
proportionately with the resistance of the
small arteries, was recorded simultaneously.
RESULTS: In the CAD group, the PWVao and
aortic augmentation index (Alxao) values
increased significantly (10.1 ± 2.3 m/sec
and 34.2% ± 14.6%) compared to the control
group (9.6 ± 1.5 m/sec and 30.9% ± 12%;
P < 0.05). We observed similar significant
increases in the local stiffness parameters
(PWVcar and carotid augmentation index [Alxcar])
in patients with verified CAD. Further, we
found a strong correlation for PWV and AIx
values that were measured with the Arteriograph
and those obtained using the echo-tracking
method (r = 0.57, P < 0.001 for PWV; and
r = 0.65, P < 0.001 for AIx values). CONCLUSIONS:
Our results indicate that local and regional
arterial stiffness parameters provide similar
information on impaired arterial stiffening
in patients with verified CAD. ? 2011 Wiley
Periodicals, Inc. |
Can arterial stiffness parameters be measured
in the sitting position? Jens N?rnberger,Rene
Michalski,Tobias R T?rk,Anabelle Opazo Saez,Oliver
Witzke,Andreas Kribben DOI: 10.1038/hr.2010.196
Despite the introduction of arterial stiffness
measurements in the European recommendation,
pulse wave velocity (PWV) and augmentation
index (AI) are still not used routinely in
clinical practice. It would be of advantage
if such measurements were done in the sitting
position as is done for blood pressure. The
aim of this study was to evaluate whether
there is a difference in stiffness parameters
in sitting vs. supine position. Arterial
stiffness was measured in 24 healthy volunteers
and 20 patients with cardiovascular disease
using three different devices: SphygmoCor
(Atcor Medical, Sydney, Australia), Arteriograph
(TensioMed, Budapest, Hungary) and Vascular
Explorer (Enverdis, Jena, Germany). Three
measurements were performed in supine position
followed by three measurements in sitting
position. Methods were compared using correlation
and Bland-Altman analysis. There was a significant
correlation between PWV in supine and sitting
position (Arteriograph: P<0.0001, r=0.93;
Vascular Explorer; P<0.0001, r=0.87).
There were significant correlations between
AI sitting and AI supine using Arteriograph
(P<0.0001, r=0.97), Vascular Explorer
(P<0.0001, r=0.98) and SphygmoCor (P<0.0001,
r=0.96). When analyzed by Bland-Altman, PWV
and AI measurements in supine vs. sitting
showed good agreement. There was no significant
difference in PWV obtained with the three
different devices (Arteriograph 7.5±1.6?m?s(-1),
Vascular Explorer 7.3±0.9?m?s(-1), SphygmoCor
7.0±1.8?m?s(-1)). AI was significantly higher
using the Arteriograph (17.6±15.0%) than
Vascular Explorer and SphygmoCor (10.2±15.1%
and 10.3±18.1%, respectively |
|
Invasive validation of a new oscillometric
device (Arteriograph) for measuring augmentation
index, central blood pressure and aortic
pulse wave velocity. 18:59 EDT 12th September
2013 | BioPortfolio Home " Latest PubMed
Articles " Journals " Journal of
hypertension " Invasive validation of
a new oscillometric device (Arteriograph)
for measuring augmentation index, central
blood pressure and aortic pulse wave velocity.
Summary of "Invasive validation of a
new oscillometric device (Arteriograph) for
measuring augmentation index, central blood
pressure and aortic pulse wave velocity."
BACKGROUND: The importance of measuring aortic
pulse wave velocity (PWVao), aortic augmentation
index (Aix) and central systolic blood pressure
(SBPao) has been shown under different clinical
conditions; however, information on these
parameters is hard to obtain. The aim of
this study was to evaluate the accuracy of
a new, easily applicable oscillometric device
(Arteriograph), determining these parameters
simultaneously, against invasive measurements.
METHODS: Aortic Aix, SBPao and PWVao were
measured invasively during cardiac catheterization
in 16, 55 and 22 cases, respectively, and
compared with the values measured by the
Arteriograph. RESULTS: We found strong correlation
between the invasively measured aortic Aix
and the oscillometrically measured brachial
Aix on either beat-to-beat or mean value
per patient basis (r = 0.9, P < 0.001;
r = 0.94, P < 0.001), which allowed the
noninvasive calculation of the aortic Aix
without using generalized transfer function.
Similarly strong correlation (r = 0.95, P
< 0.001) was found between the invasively
measured and the noninvasively calculated
central SBPao; furthermore, the BHS assessment
of the paired differences fulfilled the 'B'
grading. The PWVao values measured invasively
and by Arteriograph were 9.41 +/- 1.8 m/s
and 9.46 +/- 1.8 m/s, respectively (mean
+/- SD); furthermore, the Pearson's correlation
was 0.91 (P < 0.001). The limits of agreement
were 11.4% for aortic Aix and 1.59 m/s for
PWVao. CONCLUSION: Aix, SBPao and PWVao,
measured oscillometrically, showed strong
correlation with the invasively obtained
values. The observed limits of agreement
are encouragingly low for accepting the method
for clinical use. Our results suggest that
the PWVao values, measured by Arteriograph,
are close to the true aortic PWV, determined
invasively. Affiliation aHeart Institute,
Medical School, University of P?cs, P?cs,
Hungary bDepartment of Cardiology, University
of Rome La Sapienza, Polo Pontino, Italy.
Journal Details This article was published
in the following journal. |
Am J Hypertens. 2013 Aug 31. [Epub ahead
of print] Invasive Validation of Arteriograph
Estimates of Central Blood Pressure in Patients
With Type 2 Diabetes. Rossen NB, Laugesen
E, Peters CD, Ebbeh?j E, Knudsen ST, Poulsen
PL, B?tker HE, Hansen KW. Author information
" Department of Medicine, Silkeborg
Regional Hospital, Silkeborg, Denmark. Abstract
BACKGROUND: Central blood pressure (BP) has
attracted increasing interest because of
a potential superiority over brachial BP
in predicting cardiovascular morbidity and
mortality. Several devices estimating central
BP noninvasively are now available. The aim
of our study was to determine the validity
of the Arteriograph, a brachial cuff-based,
oscillometric device, in patients with type
2 diabetes. METHODS: We measured central
BP invasively and compared it with the Arteriograph-estimated
values in 22 type 2 diabetic patients referred
to elective coronary angiography. RESULTS:
The difference (invasively measured BP minus
Arteriograph-estimated BP) in central systolic
BP (SBP) was 4.4±8.7mm Hg (P = 0.03). The
limits of agreement were ±17.1mm Hg. CONCLUSIONS:
Compared with invasively measured central
SBP, we found a systematic underestimation
by the Arteriograph. However, the limits
of agreement were similar to the previous
Arteriograph validation study and to the
invasive validation studies of other brachial
cuff-based, oscillometric devices. A limitation
in our study was the large number of patients
(n = 14 of 36) in which the Arteriograph
was unable to analyze the pressure curves.
In a research setting, the Arteriograph seems
applicable in patients with type 2 diabetes.
CLINICAL TRAIL REGISTRATION: ClinicalTrials.gov
ID NCT01538290. KEYWORDS: blood pressure,
brachial cuff-based, oscillometric devices
for measurement of central BP, cardiovascular
disease, cardiovascular risk, central blood
pressure (BP), diabetes, hypertension, invasive
validation of brachial cuff-based, oscillometric
devices noninvasive measurement of central
BP.
Invasive Validation of Arteriograph Estimates
of Central Blood Pressure in Patients With
Type 2 Diabetes 1. Niklas Blach Rossen1,2,
2. Esben Laugesen2, 3. Christian Daugaard
Peters3, 4. Eva Ebbeh?j2, 5. S?ren Tang Knudsen2,
6. Per L?gstrup Poulsen2, 7. Hans Erik B?tker4
and 8. Klavs W?rgler Hansen1 + Author Affiliations
1. 1 Department of Medicine, Silkeborg Regional
Hospital, Silkeborg, Denmark; 2. 2 Department
of Endocrinology and Internal Medicine, Aarhus
University Hospital, Aarhus, Denmark; 3.
3 Department of Renal Medicine, Aarhus University
Hospital, Aarhus, Denmark; 4. 4 Department
of Cardiology, Aarhus University Hospital,
Aarhus, Denmark. 1. Correspondence: Niklas
Blach Rossen (niklas.rossen@rm.dk). Received
April 15, 2013. Revision received August
6, 2013. Accepted August 7, 2013. Abstract
BACKGROUND Central blood pressure (BP) has
attracted increasing interest because of
a potential superiority over brachial BP
in predicting cardiovascular morbidity and
mortality. Several devices estimating central
BP noninvasively are now available. The aim
of our study was to determine the validity
of the Arteriograph, a brachial cuff-based,
oscillometric device, in patients with type
2 diabetes. METHODS We measured central BP
invasively and compared it with the Arteriograph-estimated
values in 22 type 2 diabetic patients referred
to elective coronary angiography. RESULTS
The difference (invasively measured BP minus
Arteriograph-estimated BP) in central systolic
BP (SBP) was 4.4±8.7mm Hg (P = 0.03). The
limits of agreement were ±17.1mm Hg. CONCLUSIONS
Compared with invasively measured central
SBP, we found a systematic underestimation
by the Arteriograph. However, the limits
of agreement were similar to the previous
Arteriograph validation study and to the
invasive validation studies of other brachial
cuff-based, oscillometric devices. A limitation
in our study was the large number of patients
(n = 14 of 36) in which the Arteriograph
was unable to analyze the pressure curves.
In a research setting, the Arteriograph seems
applicable in patients with type 2 diabetes.
|
The Scientific World Journal Volume 2013
(2013), Article ID 792693, 6 pages http://dx.doi.org/10.1155/2013/792693
Clinical Study Evaluation of Arterial Stiffness
for Predicting Future Cardiovascular Events
in Patients with ST Segment Elevation and
Non-ST Segment Elevation Myocardial Infarction
Oguz Akkus,1 Durmus Yildiray Sahin,2 Abdi
Bozkurt,3 Kamil Nas,4 Kaz?m Serhan Ozcan,1
Mikl?s Illy?s,5 Ferenc Moln?r,6 Serafettin
Demir,7 M?cahit T?fenk,3 and Esmeray Acarturk3
1Sanliurfa Siverek State Hospital, 63600
Sanliurfa, Turkey 2Department of Cardiology,
Adana Numune Training and Research Hospital,
Adana, Turkey 3Department of Cardiology,
Faculty of Medicine, Cukurova University,
Adana, Turkey 4Department of Radiology, Szent
J?nos Hospital, Budapest, Hungary 5Heart
Institute, Faculty of Medicine, University
of P?cs, P?cs, Hungary 6Department of Hydrodynamic
Systems, Budapest University of Technology
and Economics, Budapest, Hungary 7Department
of Cardiology, Adana State Hospital, Adana,
Turkey Received 18 August 2013; Accepted
15 September 2013 Academic Editors: H. Kitabata
and E. Skalidis Copyright ? 2013 Oguz Akkus
et al. This is an open access article distributed
under the Creative Commons Attribution License,
which permits unrestricted use, distribution,
and reproduction in any medium, provided
the original work is properly cited. Abstract
Background. Arterial stiffness parameters
in patients who experienced MACE after acute
MI have not been studied sufficiently. We
investigated arterial stiffness parameters
in patients with ST segment elevation (STEMI)
and non-ST segment elevation myocardial infarction
(NSTEMI). Methods. Ninety-four patients with
acute MI (45 STEMI and 49 NSTEMI) were included
in the study. Arterial stiffness was assessed
noninvasively by using TensioMed Arteriograph.
Results. Arterial stiffness parameters were
found to be higher in NSTEMI group but did
not achieve statistical significance apart
from pulse pressure . There was no significant
difference at MACE rates between two groups.
Pulse pressure and heart rate were also significantly
higher in MACE observed group. Aortic pulse
wave velocity (PWV), aortic augmentation
index (AI), systolic area index (SAI), heart
rate, and pulse pressure were higher; ejection
fraction, the return time (RT), diastolic
reflex area (DRA), and diastolic area index
(DAI) were significantly lower in patients
with major cardiovascular events. However,
PWV, heart rate, and ejection fraction were
independent indicators at development of
MACE. Conclusions. Parameters of arterial
stiffness and MACE rates were similar in
patients with STEMI and NSTEMI in one year
followup. The independent prognostic indicator
aortic PWV may be an easy and reliable method
for determining the risk of future events
in patients hospitalized with acute MI. 1.
Introduction Acute myocardial infarction
(AMI) continues a worldwide cause of mortality
[1]. In-hospital and 6-month-mortality are
approximately 5-7% versus 12-13%, respectively
[2, 3]. Estimated risk of mortality for AMI
is based on the clinical status of the patients
[4]. Recent studies showed that conventional
risk factors are inadequate for predicting
cardiovascular (CV) mortality and morbidity.
A novel risk factor called arterial stiffness,
which is a defined reduction of the compliance
of arterial wall, and relationship between
coronary heart disease (CHD) have been demonstrated.
Arterial stiffness results in faster reflection
of the forward pulse wave from bifurcation
points in peripheral vessels. As a result
of new waveform, systolic blood pressure
(SBP) increases, diastolic blood pressure
(DBP) decreases, cardiac workload increases,
and coronary perfusion falls down. It plays
a major role in the determination of cardiovascular
outcomes, and it is not inferior to the traditional
risk factors to assess the future risk [5,
6]. Elevated arterial stiffness is associated
with increased major adverse cardiovascular
events (MACE) such as unstable angina, AMI,
coronary revascularization, heart failure,
stroke, and death [7]. Arterial stiffness
parameters including mean arterial pressure
(MAP), pulse pressure (PP), PWV (m/s), and
augmentation index (AI) are directly proportional
to the risk of MACE [8-10]. PWV is a susceptible
diagnostic element, and it is also involved
in risk stratification for subclinical organ
damages [11]. Few studies regarding arterial
stiffness demonstrated that PWV exhibits
a close effect with coronary heart disease
[5, 12, 13]. Whether arterial stiffness parameters
are related to MACE after acute MI has not
been studied sufficiently. The aim of our
study was to compare arterial stiffness parameters
in patients with ST segment elevation (STEMI)
and non-ST segment elevation myocardial infarction
(NSTEMI) and to validate its prognostic value.
2. Patients Ninety-four patients with acute
MI (72 men and 22 women, mean age 60,41 ±
11,17) were included in the study. There
were 45 STEMI and 49 NSTEMI. Data of patients
were analyzed within 24 hours after hospitalization.
All patients received eligible treatment
according to ESC guidelines. The choice of
preparations was entrusted to the investigator.
Hemodynamically compromised patients (Killip
classifications II, III, and IV), patients
with chronic atrial fibrillation and/or flutter,
chronic renal failure, mild-severe valvular
heart diseases and other chronic diseases
were excluded. Our local ethics committee
approved the study, and written informed
consent was obtained from all participants.
Patients were followed up for 12 months.
3. Diagnosis of Acute Myocardial Infarction
Diagnosis of AMI was based on symptoms, elevated
cardiac markers, and electrocardiogram (ECG)
changes. Patients with typical chest pain
plus ECG changes indicative of an AMI (pathologic
Q waves, at least 1?mm ST segment elevation
in any 2 or more contiguous limb leads or
new left bundle branch block, or new persistent
ST segment and T wave changes diagnostic
of a non-Q wave myocardial infarction) or
a plasma level of cardiac troponin-T level
above normal. 4. Laboratory Findings Troponin
T, creatine kinase-MB fraction (CK-MB), serum
urea, creatinine, eGFR, and other hematological
parameters were checked at the admission.
Risk factors, such as hypertension, hyperlipidemia,
diabetes mellitus, cigarette smoking, and
family history, were recorded. Hypertension
was considered as SBP and DBP greater than
140?mmHg and 90?mmHg, respectively, using
an antihypertensive medication. Diabetes
mellitus, hyperlipidemia, and hypertriglyceridemia
were defined as using antidiabetic drugs
or fasting blood glucose over 126?mg/dL,
as plasma low-density lipoprotein cholesterol
(LDL-C) >130?mg/dL, using lipid-lowering
drugs at the time of investigation, and as
TG level >150?mg/dL, respectively, according
to the Third Report of the National Cholesterol
Education Program guidelines. First-degree
relatives who are exposed to coronary artery
disease (CAD) before the age for male is
<55 and female <65 were considered
as family history. 5. Pulse Waveform Analysis
Assessment of arterial stiffness was performed
noninvasively with the commercially available
TensioMed Arteriograph. We collected the
oscillometric pulse waves from the patients.
We measured the distance between the jugulum-symphysis
(which is equal to the distance between the
aortic root and the aortic bifurcation),
and PWV was calculated. Pulse waves were
recorded at suprasystolic pressure. The oscillation
signs were identified from the cuff inflated
at least >35?mmHg above the systolic blood
pressure. In this state there was a complete
brachial artery occlusion, and it functions
as a membrane before the cuff. Pulse waves
hit the membrane, and oscillometric waves
were measured by the device and we could
see the waveforms on the monitor. The AI
was defined as the ratio of the difference
between the second (P2 appearing because
of the reflection of the first pulse wave)
and first systolic peaks (P1 induced by the
heart systole) to pulse pressure (PP), and
it was expressed as a percentage of the ratio
(AI = [P2 ? P1]/PP × 100). SBP, DBP, PP,
and heart rate and other hemodynamic parameters
as return time (RT in sec.), diastolic reflection
area (DRA), systolic area index (SAI %),
and diastolic area index (DAI %) were measured
noninvasively. DRA reflects the quality of
the coronary arterial diastolic filling (SAI
and DAI are the areas of systolic and diastolic
portions under the pulse wave curve of a
complete cardiac cycle, resp.). Hence, the
bigger the DAI and DRA are, the better the
coronary perfusion is. Furthermore, RT is
the PWV time from the aortic root until the
bifurcation and return, so this value is
smaller as the aortic wall is stiffer. |
Smoking and Hypertension Associated With
Greater Arterial Stiffness in People Aging
With HIV By Fred Furtado From TheBodyPRO.com
November 8, 2013 Having HIV is not independently
associated with arterial stiffness -- a trait
linked to cardiovascular disease risk --
despite HIV-infected individuals having a
modest, but clinically significant, increase
in arterial stiffness when compared to their
uninfected counterparts. Instead, factors
such as smoking and hypertension may account
for the increase, according to study results
presented at EACS 2013 in Brussels, Belgium.
To provide some background, HIV infection
has been associated with an increased risk
of cardiovascular disease and one of the
markers for this condition is arterial stiffness,
which is measured by pulse wave velocity
(PWV), or how fast blood moves through the
circulatory system. With age, or other changes
to the arterial wall, blood vessels become
stiffer and blood moves faster through the
system, giving the heart less time to rest.
PWV is directly dependent on mean arterial
pressure (MAP) and past research has shown
that an increase of 1 m/s (meter per second)
in PWV is associated with a 14% greater incidence
in total cardiovascular events. However,
studies measuring PWV in HIV-infected patients
have been small and their results inconsistent.
So, researchers led by Katherine Kooij, M.D.,
compared PWV in a cohort of HIV-infected
and HIV-uninfected people to determine if
there is an independent association between
HIV and PWV, as well as possible determinants
of PWV. Advertisement The study included
566 HIV-infected and 511 HIV-uninfected individuals,
all 45 or older. Both groups had comparable
median ages (52.8 versus 52), gender distribution
(89.1% men versus 86% men) and proportion
of men who have sex with men (76.4% versus
71.4%). However, the HIV-infected group included
more current smokers (32.9% versus 24.8%)
and users of antihypertensive drugs (31.3%
versus 22.4%). The HIV-infected participants
also displayed higher levels of inflammation
and immune activation markers, such as hs-CRP
and sCD163. The researchers performed three
measurements of PWV, as well as systolic
and diastolic blood pressure, using an Arteriograph
system, which registers oscillometric pressure
waves in the aorta through an upper arm cuff.
Additional information on potential determinants
of arterial stiffness was collected with
laboratory measurements and questionnaires.
The data underwent a statistical analysis
with multivariable linear regression models
using PWV as a dependent variable, adjusted
for MAP. The analysis revealed a slightly
higher, but significant unadjusted PWV in
HIV-infected individuals than in HIV-uninfected
individuals (7.9 m/s versus 7.7 m/s, P =
.004). When these results were adjusted for
MAP and gender, the difference between the
two remained at 0.19 m/s (P = .04). If compared
to a PWV increase due to age (+0.29 m/s per
5 years older, P < .001), having a positive
HIV status would be the equivalent of being
3 to 3.5 years older. However, when the PWV
values were adjusted for other factors, such
as smoking and use of antihypertensive drugs,
HIV-infected status was no longer independently
associated with arterial stiffness. In this
setting, the difference between HIV-infected
and HIV-uninfected PWV was only 0.022 m/s
(P = .8). In contrast, every 5 pack-years
(smoking 20 cigarettes a day per year, about
7,305 cigarettes) for current smokers accounted
for a difference of 0.121 m/s (P < .001),
while use of antihypertensive drugs represented
an increase of 0.527 m/s (P < .001). The
researchers also found that the inflammation
marker hs-CRP and the monocyte activation
marker sCD163 were associated with a higher
PWV: 0.039 m/s (P = .001) and 0.056 m/s (P
= .04), respectively. But sCD163 was only
a significant determinant in men. |
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