Patients undergoing invasive cardiac procedures are routinely fasted
for varying periods of time even though there is no clearly applicable
evidence-base to support current practices. We read with great interest
the study by Hamid et al exploring the occurrence of emergency
endotracheal intubation and peri-procedural aspiration pneumonia following
elective and planned inpatient percutaneous coronary intervention (PCI) in...
Patients undergoing invasive cardiac procedures are routinely fasted
for varying periods of time even though there is no clearly applicable
evidence-base to support current practices. We read with great interest
the study by Hamid et al exploring the occurrence of emergency
endotracheal intubation and peri-procedural aspiration pneumonia following
elective and planned inpatient percutaneous coronary intervention (PCI) in
their practice.1 This is the first published study in the peer-reviewed
literature that specifically addresses the issue of fasting prior to any
cardiac procedure. Considering that it involved retrospective analysis of
existing data, the wider applicability of the results may be limited, but
their paper would crucially serve to raise awareness amongst the
profession on this issue.
The custom of fasting patients prior to cardiac procedures appear to
have evolved from fasting guidelines for general anaesthesia (GA) in the
operating theatre. Induction of GA results in depression of cough and
swallow reflexes, which can predispose individuals to aspiration of
gastric contents. There is a theoretical risk that conscious sedation may
depress the cough and swallow reflexes similar to GA. It is interesting to
read that the Cardiology teams at the authors' host institutions have
'abandoned' the non-evidence based practice of fasting patients prior to
PCI and observed no adverse patient outcomes, although these patients had
varying amounts of intravenous sedation.
In a Cochrane review in 2003 it was concluded that there is no
evidence to suggest a shortened fluid fast results in increased risk of
aspiration or related morbidity compared with the traditional 'nil by
mouth from midnight' policy for patients undergoing GA.2 Although there
have been some recent small studies on fasting, the evidence base to
determine the optimal period of pre-procedural fasting has been
exceedingly slow to develop. Recent European anaesthetic guidelines have
recommended clear fluid intake to be continued for up to two hours prior
to GA.3 Similar recommendations have been made by the Association of
Anaesthetists of Great Britain and Ireland, and the American Society of
Anesthesiologists. There are no consensus guidelines on the optimal period
of fasting required prior to the wide spectrum of invasive cardiac
procedures that may involve local anaesthetic, conscious sedation or GA.
This probably reflects the poor evidence base. As a result, practice is
largely based on often poorly-referenced local guidelines that differ
between institutions.
It is incredible how, within a specialty as evidence-based as
Cardiology, we have managed to accumulate such little evidence on
appropriate fasting (indeed if at all needed) prior to any cardiac
procedure. The study by Hamid et al is refreshing, however a more robust
evidence base would be crucial to 1) establish best practice and 2)
promote consistency of such practice within the Cardiology community. Is
there any rationale in advising patients to fast at all prior to cardiac
procedures under local anaesthetic (eg. diagnostic left and right heart
catheterisation or implantation of a loop recorder) where there is a
negligible risk of complication involving peri-procedural intubation? How
long should patients fast prior to cardiac procedures such as pacemaker
implantation or lead revision under conscious sedation (if at all)? There
is a crucial and ever-pressing need for well-designed, multicentre
prospective randomised controlled trials and engagement within the
international cardiology community to attempt to address these questions.
References
1. Hamid T, Aleem Q, Lau Y, et al. Pre-procedural fasting for
coronary interventions: is it time to change practice? Heart 2014. doi:
10.1136/heartjnl-2013-305289. [Epub ahead of print]
2. Brady M, Kinn S, Stuart P. Preoperative fasting for adults to
prevent perioperative complications. Cochrane database of systematic
reviews 2003; CD004423. doi:10.1002/14651858.CD004423 [online]
3. Smith I, Kranke P, Murat I, et al. Perioperative fasting in adults
and children: guidelines from the European Society of Anaesthesiology.
European journal of anaesthesiology 2011;28: 556-69.
Under-representation of Frail or Medically Compromised Hypertensive
Older People in the Paper
Gulistan Bahat*, Asli Tufan, Mehmet Akif Karan
Department of Internal Medicine, Division of Geriatrics, Istanbul
Medical School, Istanbul University, Capa, 34390, Istanbul, Turkey
Last name of authors: Bahat, Tufan, Karan
Corresponding author: Gulistan Bahat
Address: Istanbul University, Istanbul Medical School, Department of
Internal Medicine, Capa, 34390, Istanbul, Turkey
Telephone: + 90 212 414 20 00-33204
Fax: + 90 212 532 42 08
E-mail address: gbahatozturk@yahoo.com
Dear Editor,
We have read the article by Briasoulis et al. on effect of
antihypertensive treatment in patients over 65 years of age with great
interest [1]. They comprehensively reviewed prospective randomized trials
and assessed the effects of antihypertensive treatment on cardiovascular,
all-cause mortality, stroke and heart failure in patients over 65 years of
age.By the way of 18 clinically relevant studies, they concluded that
treatment to blood pressure target of 150/80 mm Hg or to blood pressure
reduction of >25/10 mm Hg effectively decreases all-cause mortality,
cardiovascular mortality, stroke and heart failure in patients over 65
years of age.
However, elderly constitute a rather heterogeneous population and
study recommendations could only be generalized to a given population if
the given study participants are real and good representative of the
population they recommend for. Departures from representativeness are
amplified with increasing age. Progressively older adults who do
participate in studies, may be progressively less representative of the
group they are intended to reflect -as more non-representatively vigorous
and robust. Consequently, the older the age, the greater the disparity
may be between what is recommended based on 'evidence' and what is best
for the patient [2].
The randomized trials that showed benefit from the treatment of
hypertension in older adults included relatively fit patients [3].
Accordingly, older adults who are frail may not benefit from
antihypertensive therapy. There are some recent reports pointing out this
problem. In a study of 2340 adults >65 years in 2012, among frail
adults, there was no association between blood pressure and mortality.
Moreover, a higher blood pressure was associated with a lower risk of
death among the most frail (ie, those who could not walk the distance at
all) [4]. Another exampe is that, in a study of 1562 Latino adults aged 60
-101 years, the relationship between systolic blood pressure and mortality
was reported to vary by self-reported walking speed. Higher systolic blood
pressure was associated with an elevated risk of mortality in fast walkers
while not in slow walkers [5].
We conclude that Briasoulis et al.'s conclusion could not be
generalized to the elderly >65 years of age due to under-representation
of frail or medically compromised patients that are rather prevalent in
this age group . We think that their conclusion should be considered in
view of this important limitation.
References
1. Cardiac risk factors and prevention: Effects of antihypertensive
treatment in patients over 65 years of age: a meta-analysis of randomised
controlled studies. Briasoulis A, Agarwal V, Tousoulis D, Stefanadis C.
Heart 2014;100:317-323.
2. Golomb BA, Chan VT, Evans MA, Koperski S, White HL, Criqui MH. The
older the better: are elderly study participants more non-representative?
A cross-sectional analysis of clinical trial and observational study
samples. BMJ Open. 2012;2:pii e000833.
3. Egan BM. Section Editors: Bakris GL, Kaplan NM, Schmader KE. Treatment
of hypertension in the elderly patient, particularly isolated systolic
hypertension.
http://www.uptodate.com/contents/treatment-of-hypertension-in-the-elderly-
patient-particularly-isolated-systolic-
hypertension?source=search_result&search=hypertension+elderly&selectedTitle=1%7E150#H14493503
(accessed on March 6, 2014).
4. Odden MC, Peralta CA, Haan MN, Covinsky KE. Rethinking the association
of high blood pressure with mortality in elderly adults: the impact of
frailty. Arch Intern Med 2012; 172:1162.
5. Odden MC, Covinsky KE, Neuhaus JM, Mayeda ER, Peralta CA, Haan MN. The
association of blood pressure and mortality differs by self-reported
walking speed in older Latinos. J Gerontol A Biol Sci Med Sci. 2012;67:977
-83.
We read with interest, and we congratulate the authors for it, the
nice paper by Kalsch et al, which demonstrates that aortic valve
calcification (AVC) by computed tomography (CT), builds on Framingham
score for risk stratification of future cardiovascular events. These are
important data for preventive strategies, obtained in a wide and
prospective study of healthy asymptomatics.
In the discussion, the authors state tha...
We read with interest, and we congratulate the authors for it, the
nice paper by Kalsch et al, which demonstrates that aortic valve
calcification (AVC) by computed tomography (CT), builds on Framingham
score for risk stratification of future cardiovascular events. These are
important data for preventive strategies, obtained in a wide and
prospective study of healthy asymptomatics.
In the discussion, the authors state that "Detection of degenerative
aortic valve disease by assessing the prevalence of AVC can easily be
performed by echocardiography" and that both echo and CT "provide a high
degree of accuracy and reproducibility of AVC, with a higher degree of
sensitivity provided by echocardiography but with less specificity than
cardiac CT.". This difference can be understood in light of the known
inability of ultrasound to differentiate between severe fibrosis and
calcification, which inflates sensitivity but increases false-positive
rate as long as calcium is the only endpoint; we want to stress that this
"limitation" might also represent an advantage of ultrasound compared to
CT, since fibrosis may also represent a marker of disease which is worth
to detect.
In a very recent paper from our group, too recent to be cited in the
current paper, entitled "Aortic valve sclerosis as a marker of coronary
artery atherosclerosis; a multicenter study of a large population with a
low prevalence of coronary artery disease", Rossi A et al demontrated that
the presence of AV sclerosis/calcification at echocardiography gives a
patient 20 times (OR 21.8, 95CI 6.6-71.9, p <0.0001) the probability
of angiographically obstructive CAD (in patients undergoing diagnostic
coronary angiography before mitral surgery) after correction for the most
relevant clinical factors.
These data add to a wealth of literature demonstrating relevant value of
heart valve sclerosis/calcification at ultrasound to predict coronary
disease or coronary calcium or cardiovascular events, as also seen in
prospective studies, such as the cardiovascular health or MESA study.
CT has been fundamental to demonstrate the highly predictive value of
coronary calcium and then that cardiac valve calcifications do relate to
coronary calcium, also predicting cardiovascular events incrementally to
Framingham score. Now it's time to prospectively test echocardiography, an
incredibly easy, low-cost and radiation-free method, to investigate the
potential of ultrasound cardiac calcium to risk-reclassify asymptomatic
subjects.
Thanks
1- Department of Cardiac Surgery, Central Hospital Bad Berka, Germany
2- Department of Cardiac Surgery, Heart Center Leipzig, University
Leipzig, Germany
1- Department of Cardiac Surgery, Central Hospital Bad Berka, Germany
2- Department of Cardiac Surgery, Heart Center Leipzig, University
Leipzig, Germany
Corresponding author: Evaldas Girdauskas, MD, PhD (Address:
Department of Cardiac Surgery, Central Hospital Bad Berka, Robert-Koch-
Allee 9, 99437 Bad Berka, Germany. Tel.: +49 3645851101; Fax: +49
3645853510 E-mail address: egirdauskas@web.de)
We read with a great interest the manuscript by Detaint and co-
authors published in the last issue of Heart [1]. The authors should be
congratulated for their efforts to shine some light on the controversial
issue of bicuspid aortic valve (BAV)-associated aorthopathy in their
current longitudinal echocardiographic study. Indeed, there are some novel
and intriguing findings in this manuscript which may deserve a more
extensive commentary.
The authors were able to demonstrate the fastest aortic dilatation
rate at the ascending aortic level and smaller baseline aortic diameter
being predictor of rapid aortic progression. Importantly, no correlation
was found between aortic dilatation rate and BAV morphology as well as
basic aortic phenotype. Typical morphology of BAV (i.e., L-R BAV fusion
pattern) was independently associated with the baseline dilatation of the
entire aortic root, which may reflect specific patterns of transvalvular
flow in this BAV subtype [2].
The BAV population analyzed in this study is quite distinct from the
"typical" surgical BAV population and these differences should be
highlighted. First of all, 113/353 (32%) BAV patients without raphe were
identified in the current study. In our experience, it is rather rare to
find a BAV without raphe during aortic valve replacement (AVR) surgery.
Similarly, BAV without raphe was identified in only 7% patients in the
surgical series by Sievers and co-authors [3]. Another major difference is
the low proportion of patients with a BAV stenosis in the study (i.e., 14%
of the study population). Calcific stenosis is the most common fate of
congenital BAV (i.e., accounts for up 85% of surgically treated patients
[4]) which is clearly underrepresented in the current series. As opposed
to this, the authors revealed significant (i.e., at least moderate) BAV
insufficiency in 123/353 (35%) study patients. Therefore, BAV cohort
analyzed in this manuscript may represent a specific referral pattern of
the tertiary care center. How many patients underwent AVR surgery during
study period? Were these patients excluded from further echocardiographic
follow-up? Is there any role of the variable "AVR surgery" in the
progression of aortic diameters?
Was there a subgroup of BAV patients with the maximal progression of
aortic diameters at the level of the sinuses of Valsalva? There is some
evidence in the literature that patients with so-called "root phenotype"
(i.e., Valsalva sinuses > ascending aorta) may represent a
predominantly congenital form of BAV disease which is associated with a
higher risk of adverse aortic events [5]. What was the proportion of BAV
patients in the subgroup of "sinuses phenotype" which showed stable aortic
diameters at follow-up echocardiography?
However, the most intriguing question from this manuscript - why did
aortic diameters remain stable in nearly half of the BAV patients? Is
this only a function of limited echocardiographic follow-up interval
(i.e., aortopathy would progress over longer follow-up periods) or a real
phenotypic difference in BAV patients? Provided that it is a real
phenotypic difference- what are the predictors of non-progressive
aortopathy in BAV disease? Obviously, this issue was not the main focus of
the current manuscript and no specific analysis has been performed.
However, based on the presented data, risk stratification for aortic
events based on BAV morphology and baseline aortic diameter would be
inadequate. A higher level of complexity in determinants of BAV-associated
aortopathy has been proposed by the authors. In our opinion, this
question will be impossible to address without knowing the precise
haemodynamic profile of transvalvular flow in these BAV patients.
Moreover, the presented data underscore still significant gaps in
knowledge in the development of BAV aortopathy.
References
1. Detaint D, Michelena HI, Nkomo VT, Vahanian A, Jondeau G, Sarano
ME. Aortic dilatation patterns and rates in adults with bicuspid aortic
valves: a comparative study with Marfan syndrome and degenerative
aortopathy. Heart. 2014;100:126-34.
2. Mahadevia R, Barker AJ, Schnell S, Entezari P, Kansal P, Fedak PW,
Malaisrie SC, McCarthy P, Collins J, Carr J, Markl M. Bicuspid Aortic Cusp
Fusion Morphology Alters Aortic 3D Outflow Patterns, Wall Shear Stress and
Expression of Aortopathy. Circulation. 2013 Dec 17.
3. Sievers HH, Schmidtke C. A classification system for the bicuspid
aortic valve from 304 surgical specimens. J Thorac Cardiovasc Surg.
2007;133:1226-33.
4. Sabet HY, Edwards WD, Tazelaar HD, Daly RC. Congenitally bicuspid
aortic valves: a surgical pathology study of 542 cases (1991 through 1996)
and a literature review of 2,715 additional cases. Mayo Clin Proc.
1999;74:14-26.
5. Girdauskas E, Disha K, Secknus M, Borger M, Kuntze T. Increased
risk of late aortic events after isolated aortic valve replacement in
patients with bicuspid aortic valve insufficiency versus stenosis. J
Cardiovasc Surg (Torino). 2013;54:653-9.
This is an excellent article which will help many of us who have to
manage patients who are undergoing cancer treatment.
It must be remembered that many patients also undergo radiotherapy,
as is acknowledged in the article. High dose radiotherapy to the thorax
can cause heart failure, both systolic and restrictive, valvular
dysfunction and coronary artery disease, which often presents many years
later. In lymp...
This is an excellent article which will help many of us who have to
manage patients who are undergoing cancer treatment.
It must be remembered that many patients also undergo radiotherapy,
as is acknowledged in the article. High dose radiotherapy to the thorax
can cause heart failure, both systolic and restrictive, valvular
dysfunction and coronary artery disease, which often presents many years
later. In lymphoma survivors who have received such therapy,
cardiovascular disease is the most common cause of death.
A history of thoracic radiotherapy is important to elicit when
assessing patients with cardiovascular symptoms. Such patients may present
with symptoms of cardiac disease at a younger age than is typical, with
few traditional risk factors, and are therefore potentially at higher risk
of initial misdiagnosis.
We really appreciate the clarifications offered by Alexandros
Briasoulis concerning his article, but in our opinion our claim about the
importance of including in the meta-analysis information only (or mostly)
from elderly patients remains well founded. In this regard, the Cochrane
Hypertension Group encourages to accept only studies if 70% or more of the
participants meet the definition, or individual patient data are
a...
We really appreciate the clarifications offered by Alexandros
Briasoulis concerning his article, but in our opinion our claim about the
importance of including in the meta-analysis information only (or mostly)
from elderly patients remains well founded. In this regard, the Cochrane
Hypertension Group encourages to accept only studies if 70% or more of the
participants meet the definition, or individual patient data are
available, or data of relevant patients are provided separately allowing
specific inclusion of the population as defined (1). Moreover, the
inclusion of INVEST trial (2) in the ACCF/AHA 2011 (3) cannot be claimed
as a relevant argument to support proceeding in the same manner in the
meta-analysis, because of the inherent low level of evidence showed by
consensus. On the other hand, the INVEST trial has a very high risk of
bias. It is an open trial and no information on the sequence generation
nor the allocation concealment is provided.
We agree with the author in the conclusion showed by the secondary
analysis (4). But in fact this provides to us compelling evidence of the
importance of separating the information between young and older people.
Furthermore, it is not clear to us why these findings are said to be "in
accordance" with the results of the sensitivity analysis performed by the
author. According to the Discussion (1), the subgroup analysis of studies
with patients over 70 years showed that "the beneficial effects of
antihypertensive treatment remained significant in the first group of
studies (treatment versus placebo group)" but the meta-analysis did not
take into account blood pressure levels, thereby both papers seem to be
focused on very different issues. Also, we have not been able to read in
the last article cited (5) the assertion made on the J-curve association
in patients above or below age of 65. In fact, this study did not compare
different age subgroups any time but different blood pressure strata, and
the mean age values in each 10-mm Hg blood pressure stratum were very
similar (66-67 years).
In short, if elderly age begins at 65, we need to found our practices
on studies including real elderly people. Evidence based on the results of
studies with patients of a mean age close to 65 is not trustworthy.
(1) Gorricho J, Garjon J, Celaya MC, Muruzabal L, Montoya R, Lopez A,
Malon MDM, Saiz LC. Blood pressure targets for the treatment of patients
with hypertension and cardiovascular disease. Cochrane Database of
Systematic Reviews 2013, Issue 1. Art. No.: CD010315. DOI:
10.1002/14651858.CD010315.
(2) Pepine CJ, Handberg EM, Cooper-DeHoff RM, et al. A calcium antagonist
vs a non-calcium antagonist hypertension treatment strategy for patients
with coronary artery disease. The International Verapamil- Trandolapril
Study (INVEST): a randomized controlled trial. JAMA. 2003;290(21):2805-16.
(3) Aronow WS, Fleg JL, Pepine CJ, et al. ACCF/AHA 2011 expert consensus
document on hypertension in the elderly: a report of the American College
of Cardiology Foundation Task Force on Clinical Expert Consensus
Documents. Circulation. 2011;123:2434-2506.
(4) Denardo SJ, Gong Y, Nichols WW, et al. Blood pressure and outcomes in
very old hypertensive coronary artery disease patients: an international
verapamil ST-Trandolapril (INVEST) substudy. Am J Med. 18 2010;123:719-26.
(5) Messerli FH, Mancia G, Conti CR, et al. Dogma disputed: can
aggressively lowering blood pressure in hypertensive patients with
coronary artery disease be dangerous? Ann Intern Med. 2006;144:884-93.
Luis Carlos Saiz, Pharm D
Pharmacotherapy Research Coordinator
Navarre Health Service, Spain
Juan Erviti, Pharm D, PhD
Head of Unit, Drug Information
Navarre Health Service, Spain
We read with great interest the recent article by Bhattacharyya et.
al.1 They state that a high proportion (71/250) of stress echocardiograms
(SE) were performed on low risk patients and were inappropriate,
concluding that implementation of diagnostic appropriateness criteria2
would reduce this.
Appropriateness criteria2 published in 2011 reviewed clinical
scenarios warranting SE and graded these on a scale of...
We read with great interest the recent article by Bhattacharyya et.
al.1 They state that a high proportion (71/250) of stress echocardiograms
(SE) were performed on low risk patients and were inappropriate,
concluding that implementation of diagnostic appropriateness criteria2
would reduce this.
Appropriateness criteria2 published in 2011 reviewed clinical
scenarios warranting SE and graded these on a scale of 1 to 9. Classifying
patients into 3 categories, appropriate (grade 7-9), uncertain (grade 4-6)
and inappropriate (grade 1-3). The 2013 ECS guidelines3 for investigation
of stable coronary artery disease (CAD) recommends functional testing for
patients with intermediate (15-85%) pre-test probability (PTP). However,
Bhattacharyya et. al. do not elaborate on the PTP of patients in each
classification. Thus, in accordance with new ESC guideline SE may have
been appropriate in some of the patients classified as uncertain or
inappropriate.
Furthermore, a proportion of patients classified as inappropriate
included previously revascularised patients with stable symptoms.
Cardiologists may feel obliged to perform investigations on symptomatic
previously revascularised patients, often with invasive coronary
angiography, even if they are stable with a negative SE within the
previous two years. To reduce the burden on SE, cardiac CT is a viable
alternative that demonstrates grafts and proximal stent patency.
Finally, NICE, ESC and ACC/AHA guidelines all differ in diagnostic
guidelines, enabling cardiologists to use their experience and local
expertise to select the most appropriate investigation for individual
patients.
Thank you for your correspondence with respect to our study (1). We
have read your paper (2) with interest and congratulate you on an
important paper providing further empirical evidence to support more
appropriate methods of generating body size independent cardiac indices.
We are delighted your data demonstrated the importance of fat free mass
something we and others have proposed...
Thank you for your correspondence with respect to our study (1). We
have read your paper (2) with interest and congratulate you on an
important paper providing further empirical evidence to support more
appropriate methods of generating body size independent cardiac indices.
We are delighted your data demonstrated the importance of fat free mass
something we and others have proposed empirically before and represented
in previous review articles (3, 4). Your recent study is a very insightful
contribution to this field and we hope others in the clinical field read
this work and follow suit. We feel our additional comments in the meta-
analysis support a revisionist approach to the use of cardiac indices.
We would go further though and not stop at structural data and charge
all interested groups to look at how key functional data are indexed. We
have some empirical data published in respect of longitudinal tissue
velocities (5) and we feel this work should be extended.
References
1. Utomi V, Oxborough D, Whyte GP, Somauroo J, Sharma S, Shave R, et al.
Systematic review and meta-analysis of training mode, imaging modality and
body size influences on the morphology and function of the male athlete's
heart. Heart 2013;99:1727-1733.
2. Pressler A, Haller B, Scherr J, Heitkamp D, Esefeld K, Boscheri A, et
al. Association of body composition and left ventricular dimensions in
elite athletes. European Journal of Preventive Cardiology. 2012;19(5):1194
-204.
3. Batterham A, George K, Whyte G, Sharma S, McKenna W. Scaling cardiac
structural data by body dimensions: a review of theory, practice, and
problems. Int J Sports Med. 1999;20(8):495-502.
4. Dewey F, Rosenthal D, Murphy DJ, Froelicher V, Ashley E. Does size
matter? Clinical applications of scaling cardiac size and function for
body size. Circulation. 2008;117(17):2279-87.
5. Oxborough D, Batterham AM, Shave R, Artis N, Birch KM, Whyte G, et al.
Interpretation of two-dimensional and tissue Doppler-derived strain (?)
and strain rate data: is there a need to normalize for individual
variability in left ventricular morphology? Eur J Echocardiogr.
2009;10(5):677-82.
Many thanks for your correspondence. Your recent study is a very
important contribution to this field of research.
A meta-analysis is of course dependent on the validity of the study-
level metrics that are reported by authors, and this is why we inserted
the very important point about allometric scaling in our discussion.
I have been confronted with this issue also whe...
Many thanks for your correspondence. Your recent study is a very
important contribution to this field of research.
A meta-analysis is of course dependent on the validity of the study-
level metrics that are reported by authors, and this is why we inserted
the very important point about allometric scaling in our discussion.
I have been confronted with this issue also when meta-analysing
studies on percentage flow mediated dilation, which may not be the most
precise scaling index to employ for the change in arterial diameter.
So thank you again and I personally agree with everything you say.
Dear Editor,
Maruhashi et al.[1] meticulously measured the flow-mediated changes in
brachial artery diameter with a large sample of participants. The changes
in diameter were quantified using the conventional percentage-based index
(FMD%). As usual, baseline artery diameter (Dbase) was found to be
substantially and negatively correlated with FMD%. So it seems that even
the most robust protocols and precise measurements o...
Dear Editor,
Maruhashi et al.[1] meticulously measured the flow-mediated changes in
brachial artery diameter with a large sample of participants. The changes
in diameter were quantified using the conventional percentage-based index
(FMD%). As usual, baseline artery diameter (Dbase) was found to be
substantially and negatively correlated with FMD%. So it seems that even
the most robust protocols and precise measurements of arterial diameters
cannot eradicate the FMD%-Dbase correlation. This is not surprising
because it is the FMD% index itself that causes this Dbase-dependency [2].
It seems illogical to persist in quantifying endothelial "function"
with FMD% when it is so erroneously dependent on the
structural/morphological variable that is its denominator. The FMD% index
was presumably selected to "normalise" the flow-mediated response for
variability in Dbase. But the flow-mediated response itself (measured in
mm) tends to be uncorrelated to Dbase, or is even inversely proportional
to Dbase[2]. The overriding problem is that FMD% "works" only if this flow
-mediated response is consistently, substantially and positively
proportional to Dbase. This incongruity between the nature of the
physiological change and the index used to describe that change means that
FMD% itself creates the substantial negative dependency of FMD% on Dbase
[2].
Physiological explanations have been forwarded for the FMD%-Dbase
correlation [3] but such explanations are putting the "cart before the
horse". Because the output of the protocol, the FMD% index, is the source
of the Dbase-dependency problem rather than the physiological changes that
are occurring during the protocol, any further physiological explanations
for FMD%-Dbase dependency are unsatisfactory[2]. For example, the shear
rate explanation for Dbase-dependency forwarded by Pyke et al.[3] and
repeated by Maruhashi et al.[1] is inconsistent with the fact that FMD%
depends on Dbase even when calculated from randomly-generated data with no
physiological basis at all [2]. If the flow-mediated response was scaled
to Dbase properly in the first place, there would be no substantial
negative correlation between these two variables, and so no need to
explain and correct with other variables. Such circular logic is avoided
by appropriate size scaling in the first place. Then the influence of
other important variables, e.g., shear rate, on the flow-mediated response
per se can be quantified more precisely.
I agree that Dbase should be taken into consideration as a confounder
of FMD%. A full consideration of this problem has surfaced recently and,
as in the study by Maruhashi et al.[1], been applied to age- and sex-
differences in the flow-mediated response [2]. The FMD% index is higher in
women than in men simply because FMD% does not scale properly for the
lower Dbase in women[2]. Similarly, Dbase increases with age, thus biasing
age-related changes when FMD% is selected as the outcome of interest [2].
As long as FMD% is the index used to quantify the relative flow-mediated
response, such inferential errors will occur, and these errors cannot be
corrected parsimoniously with any physiological mechanisms. If FMD% was
replaced with a more accurate scaling index, Dbase-dependency, and the
associated interpretive problems would be eradicated.
References
1. Maruhashi T, Soga J, Fujimura N, et al. Relationship between flow-
mediated vasodilation and cardiovascular risk factors in a large community
-based study. Heart 2013;991837-1842.
2. Atkinson G, Batterham AM. Allometric scaling of diameter change in
the original flow-mediated dilation protocol. Atherosclerosis 2013;226:425
-427
3. Pyke KE, Dwyer EM, Tschakovsky ME. (2004) Impact of controlling
shear rate on flow-mediated dilation responses in the brachial artery of
humans. J Appl Physiol 97: 499-508
Patients undergoing invasive cardiac procedures are routinely fasted for varying periods of time even though there is no clearly applicable evidence-base to support current practices. We read with great interest the study by Hamid et al exploring the occurrence of emergency endotracheal intubation and peri-procedural aspiration pneumonia following elective and planned inpatient percutaneous coronary intervention (PCI) in...
Under-representation of Frail or Medically Compromised Hypertensive Older People in the Paper Gulistan Bahat*, Asli Tufan, Mehmet Akif Karan
Department of Internal Medicine, Division of Geriatrics, Istanbul Medical School, Istanbul University, Capa, 34390, Istanbul, Turkey
Last name of authors: Bahat, Tufan, Karan
Corresponding author: Gulistan Bahat Address: Istanbul University, Istanbul Med...
We read with interest, and we congratulate the authors for it, the nice paper by Kalsch et al, which demonstrates that aortic valve calcification (AVC) by computed tomography (CT), builds on Framingham score for risk stratification of future cardiovascular events. These are important data for preventive strategies, obtained in a wide and prospective study of healthy asymptomatics. In the discussion, the authors state tha...
Evaldas Girdauskas1, Michael A. Borger2
1- Department of Cardiac Surgery, Central Hospital Bad Berka, Germany 2- Department of Cardiac Surgery, Heart Center Leipzig, University Leipzig, Germany
Keywords: bicuspid aortic valve, aortic aneurysm, aortopathy
Corresponding author: Evaldas Girdauskas, MD, PhD (Address: Department of Cardiac Surgery, Central Hospital Bad Berka, Robert-Koch- Allee 9,...
This is an excellent article which will help many of us who have to manage patients who are undergoing cancer treatment.
It must be remembered that many patients also undergo radiotherapy, as is acknowledged in the article. High dose radiotherapy to the thorax can cause heart failure, both systolic and restrictive, valvular dysfunction and coronary artery disease, which often presents many years later. In lymp...
We really appreciate the clarifications offered by Alexandros Briasoulis concerning his article, but in our opinion our claim about the importance of including in the meta-analysis information only (or mostly) from elderly patients remains well founded. In this regard, the Cochrane Hypertension Group encourages to accept only studies if 70% or more of the participants meet the definition, or individual patient data are a...
We read with great interest the recent article by Bhattacharyya et. al.1 They state that a high proportion (71/250) of stress echocardiograms (SE) were performed on low risk patients and were inappropriate, concluding that implementation of diagnostic appropriateness criteria2 would reduce this.
Appropriateness criteria2 published in 2011 reviewed clinical scenarios warranting SE and graded these on a scale of...
Dear Professor Pressier,
Thank you for your correspondence with respect to our study (1). We have read your paper (2) with interest and congratulate you on an important paper providing further empirical evidence to support more appropriate methods of generating body size independent cardiac indices. We are delighted your data demonstrated the importance of fat free mass something we and others have proposed...
Dear Professor Pressier,
Many thanks for your correspondence. Your recent study is a very important contribution to this field of research.
A meta-analysis is of course dependent on the validity of the study- level metrics that are reported by authors, and this is why we inserted the very important point about allometric scaling in our discussion.
I have been confronted with this issue also whe...
Dear Editor, Maruhashi et al.[1] meticulously measured the flow-mediated changes in brachial artery diameter with a large sample of participants. The changes in diameter were quantified using the conventional percentage-based index (FMD%). As usual, baseline artery diameter (Dbase) was found to be substantially and negatively correlated with FMD%. So it seems that even the most robust protocols and precise measurements o...
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