JACC: CARDIOVASCULAR IMAGING
VOL.
ª 2017 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION
-, NO. -, 2017
ISSN 1936-878X/$36.00
PUBLISHED BY ELSEVIER
LETTER TO THE EDITOR
These acquisitions were performed at 2 moments during the procedure, before and after the rapid saline loading (at the same time of the pre-CVP and post-CVP
Toward Noninvasive Assessment of CVP
measurements). The physicians performing the LS
Variations Using Real-Time and Quantitative
measurement were unaware of the CVP results.
Liver Stiffness Estimation
At baseline RHC, the mean CVP was 7.4 2.9 mm Hg (range 3 to 16 mm Hg) and the mean LS was 9.0
5.8
kPa
(range
4
to
46.1
kPa).
After
Heart failure is the main cause of morbidity and
volume loading, the mean CVP increased signifi-
mortality in cardiac patients, and may cause the
cantly to 10.0 3.3 mm Hg (range 3 to 18 mm Hg)
dysfunctions of multiple organs as a result of
(p < 10–4 ) and the mean LS increased significantly to
various interactions. A right heart dysfunction can
14.4 9.1 kPa (range 4.3 to 72 kPa) (p < 10–4 ). LS
induce signs of congestive right heart due to the
strongly correlated with CVP, pre-loading (r ¼ 0.86;
increase of filling pressures, with direct repercussions
p < 10–4 ) and post-loading (r ¼ 0.87; p < 10–4 ) (Figure 1).
on the liver (hepatic congestion). Currently, the in-
All patients who had an increasing CVP also had an
direct estimation of filling pressures of the right heart
increasing LS (93 of 103 patients). In addition, all
is achieved through clinical examination and ultra-
patients who had a decreasing CVP also had a
sound parameters. Right heart catheterization (RHC)
decreasing LS (10 of 103 patients).
is the gold standard to measure central venous pres-
Optimal cutoff value of LS for detection of CVP
sure (CVP) (1) but it is invasive, costly, and cannot be
>10 mm Hg was 10.8 kPa (sensibility ¼ 89.3%,
repeated for close follow-up, particularly on children.
specificity ¼ 86.0%), with an area under the curve of
Liver elastography was initially developed to
0.946 (95% confidence interval: 0.920 to 0.971; p ¼ 0.01).
analyze the tissue properties of this organ, especially
Beyond this correlation, LS is sufficient to provide an
for the grading of cirrhosis. It is important to note that
indirect and reliable measurement of quantitative CVP
congestion alters the intrinsic rigidity of the liver (2).
variations (r ¼ 0.86, r ¼ 0.756, p < 10-4; multivariate
For this reason, recent studies have demonstrated
model). Inferior vena cava diameter (r ¼ 0.40,
that liver stiffness (LS) and CVP are correlated (3,4). limitations and the potential usefulness of LS mea-
r ¼ 0.408, p ¼ 0.01), pulsed-Doppler profile of hepatic veins (r ¼ 0.19, r ¼ 0.078, p ¼ 0.483), and N-terminal pro-B-type natriuretic peptide (r ¼ 0.10, r ¼ 0.038,
surement using shear wave elastography (SWE) as a
p ¼ 0.736) were less robust than LS to estimate CVP.
Until now, however, these studies have had technical
reliable and quantitative surrogate of CVP in clinical
The intraoperator and interoperator reproduc-
practice needs further developments. To our knowl-
ibility of the LS measurement technique were studied
edge, no clinical studies have been conducted on
in 20 patients, and we found no significant statistical
humans to link the CVP and the LS estimated by SWE
difference.
in real time.
For children with congenital heart disease and
Here we sought to determine whether LS estimated
no argument for tissue liver anomalies, nonin-
by SWE could reliably estimate the measurement of
vasive and quantitative estimation of filling pressures
CVP during RHC. In addition, we investigated whether
can be very difficult to perform. The paradox is that
acute changes in CVP paralleled changes in LS.
the filling pressures (and specifically CVP) have been
A total of 103 children (6.8 5.5 years of age)
recognized as a major predictive parameter of adverse
referred to our institution for diagnostic or interven-
events. The management of the acute heart failure at
tional RHC were prospectively enrolled. CVP and LS
the child’s bedside depends on the evaluation of
were measured simultaneously at baseline and after 15
volume or pressure overload (5). That is why a
ml/kg of volume loading. Inferior vena cava diameter
quantitative and real-time parameter as LS by SWE
and pulsed-Doppler profile of hepatic veins were also
could be clinically necessary.
evaluated. Plasma level of N-terminal pro–B-type natriuretic peptide was assayed during the RHC.
Here, we show that LS measurement using SWE is a reliable surrogate of quantitative estimation of the
SWE was used to image LS with the Aixplorer ul-
CVP. It can also be used to measure CVP changes
trasound imaging system (Aixplorer, Supersonic
in real time. LS could potentially be a useful nonin-
Imagine, Aix-en-Provence, France) with an abdominal
vasive tool for evaluation and follow-up of acute and
curved probe (SC6-1), during the RHC procedure.
chronic right heart failure.
2
Letter to the Editor
JACC: CARDIOVASCULAR IMAGING, VOL.
-, NO. -, 2017 - 2017:-–-
F I G U R E 1 Results
Correlation between liver stiffness and central venous pressure (CVP), pre- and post-volume loading, with an example of evaluation of liver stiffness by shear wave elastography (kPa).
Olivier Villemain, MD* Fidelio Sitefane, MD Mathieu Pernot, PhD Sophie Malekzadeh-Milani, MD Mickael Tanter, PhD Damien Bonnet, MD, PhD Younes Boudjemline, MD, PhD
Please note: Dr. Tanter is cofounder of SuperSonic Imagine. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
*M3C-Necker Enfants malades
2. Millonig G, Friedrich S, Adolf S, et al. Liver stiffness is directly influenced by central venous pressure. J Hepatol 2010;52:206–10.
AP-HP, Université Paris Descartes Sorbonne Paris Cité Cardio-Vascular Department 149 rue de Sèvres Paris 75015 France E-mail:
[email protected] http://dx.doi.org/10.1016/j.jcmg.2017.01.018
REFERENCES 1. Nagueh SF, Kopelen HA, Zoghbi WA. Relation of mean right atrial pressure to echocardiographic and Doppler parameters of right atrial and right ventricular function. Circulation 1996;93:1160–9.
3. Taniguchi T, Sakata Y, Ohtani T, et al. Usefulness of transient elastography for noninvasive and reliable estimation of right-sided filling pressure in heart failure. Am J Cardiol 2014;113:552–8. 4. Jalal Z, Iriart X, De Lédinghen V, et al. Liver stiffness measurements for evaluation of central venous pressure in congenital heart diseases. Heart 2015;101:1499–504. 5. Hsu DT, Pearson GD. Heart failure in children: part II: diagnosis, treatment, and future directions. Circ Hear Fail 2009;2:490–8.
