Doppler Echocardiographic Indices in Aortic Coarctation: A Comparison of Profiles before
and After Stenting
Diaa Mohamed Shalaby1, Ahmed Moawed Alemam1, Abdelaziz rizk2, A Elsebaeyshousha3 and Sameh Refaat Allam2, Sameh I Sersar5 and Mohamed Alassal4*
1 National Heart Institute, Egypt
2Cardiology Department, Alazhar University, Egypt
3Cardiothoracic Surgery Department, Alazhar University, Egypt
4 Cardiothoracic Surgery Department, Benha University, Egypt
5Cardiothoracic Surgery Department, Mansoura University, Egypt
Submission: May 25, 2018; Published: June 27, 2018
*Corresponding author: Mohamed Abdelwahab Alassal MD, Associate Professor and Consultant Cardiothoracic Surgeon, Benha Faculty of Medicine, Egypt, Email: [email protected]
How to cite this article:Alassal M, Diaa Mohamed S, Ahmed M A, Abdelaziz r, A Elsebaeyshousha,Sameh R A, et.al. Doppler Echocardiographic Indices in Aortic
Coarctation: A Comparison of Profiles before and After Stenting. J Cardiol & Cardiovasc Ther. 2018; 11(2): 555808. DOI: 10.19080/JOCCT.2018.11.555808
Background:Aortic coarctation is one of the most common congenital heart defects. Nowadays, percutaneous stenting is an accepted form of treatment for isolated coarctation of the aorta by Balloon expandable endovascular stents, Diagnosis and evaluation of coarctation is of great importance, not only before stenting but also after implantation, in order to assess the success of procedure and occurrence of restenosis in followup. Cardiac magnetic resonance is the imaging modality of choice. However, it has limited availability or clinical contraindication. On the other hand, two-dimensional and Doppler echocardiographic techniques are simple, widely available, imaging tools which can be used for the indirect evaluation of coarctation.
Objectives:The aim of this work is to (1) evaluate the changes in a complete list of echocardiographic profiles in patients with aortic coarctation before and after stenting (2) and to determine the diagnostic value of these indices as an indicator of success of aortic coarctation stenting.
Patients and methods: This prospective study was conducted on 40 patients with a diagnosis of aortic coarctation based on angiography. Echocardiographic assessment was done twice for all patients before and after stenting, complete lists of Doppler indices were recorded for each case. After comparing the values of indices before and after stenting, diagnostic values of each index as indicator of success of procedure was statistically assessed.
Results: This study enrolled 40 patients, with diagnosed coarctation of aorta), 32 males and 8 females with a mean age of 15.14±9.17 years (range 6.5-28) were enrolled in this study, the mean length of the stenosis was 18.5+_9.5 mm. In addition, the mean baseline ejection fraction was 58.55±5.10% (range 40-60%) and 36 of patients were hypertensive. Except for the mean velocity and mean pressure gradient of the abdominal aorta, the values of the other indices of the abdominal/descending aorta showed significant change after stenting to indicate significant diagnostic accuracy for detecting success of stenting, and we recommend to use these indices as individualized reference for each case during follow up after stenting to detect incidence of restenosis. The, acceleration time, (m/s), Time to peak systolic velocity (m/s), velocity–time integral and the pressure half-time were among the indices with the highest accuracy rates for this purpose (p <0.001).
Conclusion:Post-stenting echocardiographic profiles could provide a reliable reference value of the normal aortic haemodynamics as a unique identification of each patient and it is presumed that these indices could be used as reliable indicators of response to treatment.
As one of the most common congenital heart defects aortic coarctation  has a wide morphological spectrum that varies from transverse arch and isthmal hypoplasia, which are seen most
commonly in new-born babies, to discrete stenosis or membrane like obstructions, which are typically observed in older patients .
Aortic coarctation presenting during adult life most frequently
represents cases either of re-coarctation following previous
transcatheter or surgical therapy, or missed cases of native
Nowadays, percutaneous stenting is an accepted form of
treatment for isolated coarctation of the aorta . Balloon
expandable endovascular stents have been used in various
locations since the 1980 . Stents support the integrity of
the vessel wall after balloon dilation by opposing the recoil the
elastic vascular stenosis and re-adhering the torn intima to the
media. This minimises the extension of wall tears and subsequent
dissection or aneurysm formation .
Diagnosis and evaluation of coarctation is of great importance,
not only before stenting but also after implantation, in order to
assess the occurrence of restenosis. With regard to evaluation
of aortic coarctation, cardiovascular magnetic resonance (CMR)
imaging is the procedure of choice 17. However; its use may be
limited because of lack of availability or clinical contraindications.
On one hand, echocardiography is the only available bedside
diagnostic tool. It can be used in the initial assessment and
follow up after the intervention of patients with coarctation.
Two- dimensional and Doppler techniques including analysis of
pulse-wave and continuous-wave Doppler across the coarctation
site and at the abdominal aorta are also used for the evaluation of
The aim of this work is to evaluate the changes in a complete list
of echocardiographic profiles in patients with aortic coarctation
before and after stenting, and to determine the diagnostic value of
these indices as an indicator of success of stenting.
A prospective study included 40 consecutive patients, with
a definite diagnosis of primary unoperated aortic coarctation
based on clinical, Echocardiographic study, and confirmed by
angiography, referred to the Pediatric Echo department of the
National Heart Institute for further assessment according to
the following protocol, a free written informed consent from all
patients and their parents was taken.
1. Patients with other concomitant lesions, including
aortic stenosis or regurgitation, patent ductus arteriosus or
ventricular septal defects.
2. Anomalies of the head and neck vessels.
3. Hypoplastic arch or evidence of sever collaterals during
The patients included in this study were subjected to the
a) Clinical assessment:
i. History taking (personal, history of present illness, past
ii. Clinical examination (general, local).
b) Echo-Doppler study:
i. Echocardiographic assessment with our indices enrolled
in this study was done twice for all patients, 24 hours before
and 24 hours after stenting.
ii. Doppler study was performed using a Vivid 3 Imaging
System (GE, USA) by one Echocardiologist before and after
stenting who was totally blinded from the aim of this study
iii. Descending aorta was evaluated during Doppler
echocardiography from the standard suprasternal position
with continuous-wave Doppler at coarctation site. Flow
pattern of the abdominal aorta was assessed by continous
wave Doppler obtained from subcostal view.
All studies, including pre- and post- stenting profiles, were
performed with simultaneous electrocardiographic monitoring
(ECG based), and the systole was assumed from the beginning of
QRS till the end of T wave, onset of diastole was assumed at the
end of the T wave till the end of PR segment.
Echocardiographic indices performed are defined as follows:
a. Deceleration time (DT): Measured from peak E velocity
to the point where the slope of the slowing flow would
intercept the baseline.
b. Systolic acceleration time: measured from the onset of
the systolic upstroke to the systolic peak.
c. Pressure half-time (PHT) is the time interval for the
peak pressure gradient to be reduced by one half (PHT=0.29 ×
d. Abdominal aortic pulse delay index is quantified by
measuring the time to peak velocity in the abdominal aorta
and comparing it with the same value measured from flow at
the aortic annulus. This value should be indexed to the heart
rate by dividing the absolute value by the square root of the
RR interval .
e. Pulsatility index is the systolic velocity minus diastolic
velocity divided by the mean (systolic velocity- diastolic
velocity) / mean velocity .
f. Early diastolic velocity (EDV) is maximum diastolic
velocity in early diastole .
g. Late diastolic velocity (LDV) is maximum diastolic
velocity in late diastole (atrial contraction, calculated from
end of p wave on gated ECG) .
h. Peak systolic velocity is maximum systolic velocity .
i. Velocity time integral is the area under the velocity curve
j. Time to peak systolic velocity is the time from onset of
the QRS complex to peak systolic velocity measured by pulsed
wave Doppler echocardiography .
c) Cardiac catheterization: During diagnostic
catheterization and during angioplasty for aortic coarctation
these data were obtained:
i. Site, length and width of coarctation segment.
ii. The characteristics of stenting, including length and
width of stent, length and width of balloon, and before- and
after-stent peak gradient of the catheter were recorded for
all patients (Figure 1 & 2) .
Data were entered checked and analyzed using Epi-Info
version 6 and SPP for Windows version 8. Data were summarized
using the arithmetic mean, the standard deviation, student t test
and chi-squared test.
Receiver operating characteristic curve (ROC) analysis was
performed to assess the predictability of significant coarctation
(pre-stenting condition) with the quantitative indices of the study,
and then to compare area under the curve (AUC) of these variables.
For this purpose, the first measured profiles before stenting were
considered to be the values of patients with significant aortic
coarctation, while the next measured indices after stenting were
taken as the profiles of the individuals without coarctation. The
cut-off points were then determined in each ROC analysis. The
best predictive cut-off value was the one that gave the highest
sensitivity and specificity simultaneously. The diagnostic values
of each cut-off point, including sensitivity and specificity, were
calculated and reported.
For all above mentioned statistical tests done, the threshold of
significance is fixed at 5% level (p-value).
The results were considered:
a. Significant when the probability of error is less than 5%
b. Non-significant when the probability of error is more
than 5% (p>0.05).
c. Highly significant when the probability of error is less
than 0.1% (p<0.001).
The smaller the p-value obtained, the more significant are the
This prospective study enrolled 40 patients, with diagnosed
coarctation of aorta), 32 males and 8 females with a mean age
of 15.14±9.17 years (range 6.5-28) were enrolled in this study,
the mean length of the stenosis was 18.5+_9.5mm. In addition,
the mean baseline ejection fraction was 58.55±5.10% (range
40-60%) and 36 of patients were hypertensive. All baseline and
stenting characteristics of the patients are listed in Table 1.
All values for continuous variables are mean±SD.
Regarding symptoms and signs of presentation in our cases,
40 cases was symptomatic, 2 cases (5%) complained mainly
from growth failure and dysphagia with feeding, 38 cases (95%)
complained of intermittent claudications and coldness of lower
limbs, 26 complained of exertional dyspnea (65%), by physical
examination; ejection systolic murmur over apex was found
in 34 cases (85%), brachio-femoral delay and blood pressure
discrepancy between both arms was found in 38 cases (95%),
details of symptoms and signs in our cases are listed in Table 2.
PSV: Peak Systolic Velocity; EDV: Early Diastolic Velocity; LDV: Late Diastolic Velocity; AT: Systolic Acceleration Time; PHT: Pressure Half-Time;
All p-values are from paired t-test and p <0.05 is considered significant.
The mean values of Doppler indices of the abdominal and
descending aorta (before and after stenting) and mean percentages
of changes after stenting are listed in Table 3. Stenting decreased
the pulse-delay index from 7.3±4.8 to 4.15±2.2 (p<0.001).
Additionally, significant reductions were noted in these
1. Early diastolic velocity (EDV) (p value of early diastolic
velocity-Abdomial aorta <0.001, p value EDV in descending
2. Late diastolic velocity (LDV) (p value of LDV in abdominal
aorta=0.002, p value of LDV in descending aorta <0.001).
3. Acceleration time (AT) (p value of acceleration time
in abdominal aorta <0.001, p value of acceleration time in
4. Pressure half time (PHT) (p value of PHT in abdominal
aorta <0.001, p value PHT in descending aorta <0.001).
5. Mean velocity (p value of mean velocity in abdominal
aorta <0.001, p value of mean velocity in descending aorta
6. Mean PG (p value of mean pressure gradient in
descending aorta <0.001).
7. Velocity time integral (VTI) (p value of VTI in abdominal
aorta=0.005, p value of VTI in descending aorta <0.001).
Time to peak systolic velocity was significantly increased after
stenting (p value of time to peak systolic velocity in abdominal
aorta <0.001), p value of time to peak systolic velocity in
descending aorta <0.001). The largest percentage was achieved
in the pulsatility index increased from 0. 9±0.35 to 1.95±0.6±0.51,
with percentage of increase (119.57%), p value of pulsatility
index of descending aorta <0.001).
The ROC curve analysis was performed to evaluate the
diagnostic values of different Doppler echocardiographic indices in order to differentiate significant coarctation (pre-stenting
condition) from post-stenting conditions Diagnostic values of all
12 Doppler echocardiographic indices in both the abdominal and
descending aorta are given in Table 4.
As shown in Table 4, except for the mean velocity and mean
PG of the abdominal aorta, all other indices of the abdominal
and descending aorta had a statistically significant area under
the curve (AUC) to distinguish patients with significant aortic
coarctation (pre-stenting condition) from post stenting condition.
The velocity time integral (VTI) of the descending aorta had the
greatest AUC of 0.968 (p value of VTI in descending aorta <0.001)
VTI had 95% sensitivity and 97.7% specificity for detection
of significant aortic coarctation. A pulse delay of >5.65 had a
sensitivity of 87% and specificity of 93.7% to diagnose significant
aortic coarctation. Moreover, as illustrated in Table 4, a pulsatility
index of >1.23 had 87% sensitivity and 91.7% specificity to
differentiate significant coarctation (pre-stenting condition) from
the poststenting condition.
PSV: Peak Systolic Velocity; EDV: Early Diastolic Velocity; LDV: Late Diastolic Velocity; AT: Systolic Acceleration Time; PHT: Pressure Half-Time;
PG: Peak Gradient; D/S: Diastolic Velocity/Systolic Velocity; VTI: Velocity Time Integral; AUC: Area Under Curve.
*Paired t test
PSV: Peak Systolic Velocity; EDV: Early Diastolic Velocity; LDV: Late Diastolic Velocity; AT: Systolic Acceleration Time; PHT: Pressure Half-Time;
PG: Peak Gradient; D/S: Diastolic Velocity/Systolic Velocity; VTI: Velocity Time Integral; AUC: Area Under Curve. All data derived from two-sided
Pearson correlation analysis.
As shown in Table 5, the baseline peak aortic gradient
measured by catheter was significantly correlated with some
of the pre-stenting echocardiographic profiles of the abdominal
and descending aorta, the strongest correlation of the peak
gradient was observed with pressure half-time as a direct
relationship (r abdominal aorta =0.573, p value abdominal aorta
<0.001; r descending aorta =0.584, p value descending aorta
<0.003). The velocity–time integral of the descending aorta was
also directly correlated with before-stenting peak gradients (r
descending aorta =0.632, p value descending aorta <0.010). Other
correlations are shown in Table 5. The possible correlation of the
baseline peak aortic gradient with the mean percentage change
in echocardiographic profiles after stenting was also evaluated.
Our findings showed a reverse correlation between severity of
coarctation and changes in LDV after stenting. The higher the
gradient, the lower the change in the LDV of the abdominal aorta (r
abdominal aorta =-0.567, p value of abdominal aorta =0.033). By
contrast, changes in the PHT of the abdominal aorta were directly
correlated with the baseline catheter gradient (r abdominal aorta
=0.587, p value abdominal aorta =0.001). Changes in the other
echocardiographic indices were not significantly correlated with
the baseline aortic gradient.
Congenital heart disease (CHD) occurs in approximately 8
of every 1000 live births, half of whom require surgical or other
forms of treatment. Coarctation of aorta is a complex congenital
heart defects involving the outflow tracts of the heart, the aorta
and its branches.
The embryological development of the heart and the great
vessels is one same process that goes hand in hand and this
means that the presence of an easily detected cardiac congenital
abnormality does not mean the exclusion of associated extra
cardiac vascular abnormality. It also means that the more the
complex the cardiac abnormality, the more the complex the
expected extra cardiac vascular abnormality could should be.
Major advancements in the surgical and medical management
of cases with coarctation of aorta allowed a large percentage
of these cases to survive to adulthood. This required proper
diagnosis and timed management to provide the child with a good
chance of leading normal life with minimal if any disability.
Cardiac imaging is a fundamental element of the discipline of
pediatric cardiology, required at all stages of patient care. Imaging
Provides a detailed depiction of the anatomy and physiology of
congenital heart disease (CHD), can define management and
An accurate, 3D evaluation of the cardiac and related arterial
anatomy is critical for the clinical management of pediatric patients
with complex congenital heart disease. 3D imaging has the ability
to demonstrate the shapes of, and spatial relationships between,
the great arteries, proximal and distal branch pulmonary arteries,
coronary vessels and anomalous pulmonary venous or systemic connections. Three-dimensional information about extra-cardiac
morphological characteristics may determine subsequent surgical
intervention, follow up the residuals of interventions, and assist
with estimation of prognosis.
Recent advances in diagnostic radiology have radically
altered the approach to the diagnosis of congenital heart disease
(CHD). Sophisticated trans-thoracic and transesophageal
echocardiography is perhaps the best-known example.
Additionally, state of the art magnetic resonance (MR) and
multislice computed tomography (CT) scanners, each with
cardiac packages, can render diagnostic angiocardiography
unnecessary at times. With an accurate diagnosis, interventional
angiocardiography, embolotherapy, surgical correction, or even
cardiac transplantation can be accomplished for palliation or cure.
In spite of these imaging breakthroughs, many if not most
coarctation of aorta patients, independent of age, are referred to
the radiologist with a request for a chest radiograph, either one
or two view. Plain chest x-rays have long been established as a
valuable tool in the evaluation of patients with heart murmur
or the suspicion of CHD. It had been taught that coarctation of
aorta have classic manifestations on plain chest x-ray, (Figure) for
coarctation of aorta.
The advent of echocardiography (echo) in the 1970s led to
a revolution in the non-invasive diagnosis of heart disease. Echo
became the mainstay of diagnosis and follow-up for congenital
heart disease, used to determine chamber pressures and function,
detect intracardiac anomalies, fair data about extracardiac
anatomy (pulmonary & systemic vessels) prior to surgery (Oh et
In addition to echocardiographic 2-D imaging, the Doppler
examination has become an essential component of the complete
echocardiographic evaluation. The field of cardiac US continues
to grow rapidly: recent clinical additions include 3-D imaging,
harmonic imaging, and contrast echocardiography.
Echocardiography is a great modality for initial assessment
because of its mobility and availability however; it may not be the
perfect diagnostic tool because it is usually limited by the acoustic
window, spatial resolution, and the subjective interpretation of the
operator. An incorrect echo diagnosis might result in the wrong
operation and the risk of avoidable mortality, a mistake that could
potentially have been corrected by MSCT (Tsai et al. 2008).
Cardiac catheterization has traditionally been the procedure
utilized to complement echo, providing hemodynamic information
and enabling visualization of extracardiac great vessels. However,
the role of diagnostic cardiac catheterization in pediatric
cardiology is evolving for a number of reasons.
The major advantages of digital angiocardiography include
the ability to eliminate bony structures by subtraction techniques
thus reducing the risk of motion mis-registration artifacts and
more importantly to use the sequential data to create quantitative
analyses. One of the advantages of the technique is that it is less
operator dependant, functional data like intra cardiac or intra
vascular pressure gradients or blood oxygenations levels are
On the other hand one of the potential negative repercussions
of cardiac catheterization is the invasive nature of procedure (e.g.
arterial and venous compromise, stroke, bleeding) and of the
exposure to radiation. In many centres, cardiac catheterization
is now reserved for patients in whom hemodynamic data is
essential (e.g. unexplained pulmonary hypertension), and/or in
whom interventional procedures are necessary.
Understanding the varied cardiac anatomy often requires
additional imaging, as a supplement to more traditional first-line
methods (i.e. echocardiography or cardiac catheterization). MRI
and CT has rapidly established itself as a complementary modality
to echocardiography in a wide variety of clinical scenarios where
echo is either hindered by lack of acoustic windows, or is unable
to provide all the necessary information for therapeutic decision
making. It has also decreased the need for routine diagnostic
cardiac catheterization prior to surgery.
Krishnamurthy reported that cardiovascular magnetic
resonance (CMR) imaging plays an important role in the
evaluation of patients with complex CHD. It overcomes
many of the limitations of echocardiography (e.g., restricted
acoustic windows), computed tomography (e.g., exposure to
ionizing radiation, limited functional information), and cardiac
catheterization (e.g., exposure to ionizing radiation, morbidity,
Coarctation of the aorta is characterised by anatomical
obstruction in the descending aorta. It is difficult to evaluate
this obstruction because of the variability in cardiac output,
number and size of collaterals, and peripheral resistance. (Teien
DE and Wendel H) Primary clinical diagnosis and subsequent
assessment of the severity of coarctation and re-coarctation of
the aorta have traditionally been made based on the judgment
of the character of the femoral pulse. Also known as a secondary
event, absent, weakened or delayed femoral pulses occur as a
result of obstruction in aortic coarctation. The pressure drop
across the obstruction (the gradient), pressure half-time, and
diastolic flows are widely used but inaccurate indices to diagnose
aortic coarctation. They can be affected by many other factors
such as cardiac output, lesion length, the presence of collateral
networks, and aortic compliance. (Tacy TA, Baba K) for this, CMR,
CT, traditional Echo-Doppler assessment of coarctation proved to
be sufficient tools.
Stent implantation has been used as a reliable treatment for
coarctation of the aorta. It has several advantages, rendering it
superior to angioplasty alone. Bussadori C et al. The effect of stents
on blood flow dynamics is not well known. Moreover, despite the
importance of close follow up to evaluate complications and the
long-term effect on the blood pressure of these patients, there are no adequate long-term follow-up indices for these patients.
Therefore the present study was carried out to find reliable,
quantitative Doppler echocardiographic indices for assessment
of the severity of coarctation of the aorta before stenting and
comparing these indices with the post-stenting condition. This
would provide a valuable profile to indicate successful stent
All previous methods, including monitoring the blood
pressure, two-dimensional echocardiography, cardiac magnetic
resonance (CMR) and angiography have failed to give favourable
results to rely on for early detection and follow up of restenosis,
this is evidenced by persistent hypertension, even in the absence
of a recurrent or residual stenosis, insufficient anatomical
evaluation of two-dimensional echocardiography, and disrupted
MRI by metallic artifacts (or noise) have limited the value of
these indices to assess the patient at post-intervention follow
up (Hamdan MA, Maheshwari S), Furthermore, angiography as
an invasive procedure has known complications and should be
restricted to use in cases planned only for reintervention.
Doppler echocardiography overcomes these problems in the
follow up of such patients. However, echocardiography may be
less sensitive than angiography, spiral computed tomography and
MRI in detecting aneurysms after stent placement (Hamdan MA,
Based on our results, the Doppler echocardiographic profile
was found to be valid for differentiating significant coarctation
(presenting) from the successfully stented cases (after stenting),
with high diagnostic values. As demonstrated in the results,
continuous flow was significantly decreased from before to after
stenting in both the descending and abdominal aorta. Moreover,
monophasic systolic flow was shown to increase significantly
In comparison with a few similar studies, Mivelaz & Di
Bernardo  we assessed more indices. According to our
results, aortic pulse delay decreased after stenting. The results
also showed that a pulsatility index of <1.27 was suggestive
of significant coarctation of the aorta. This cut-off point was
matching with cut-off point calculated by Shokoufeh Hajsadeghi et
al. which was <1.2, and mismatching with cut-off value of <2 in a
study by Silvilairat et al. Hagler DJ et al. Currently, it is known that
obstructed blood flow due to aortic coarctation leads to pressure
drop and loss of the pulse wave distal to the stenosis. This can be
observed by echocardiography typically as decreased pulsatility
of the abdominal aorta after cardiac systole Pfammatter JP,
Early and late diastolic velocities were found to be significant
markers in the assessment of the severity of coarctation. In
addition, mean gradient of the descending aorta was significantly
reduced by as much as 65% following stenting, this was matching
with Shokoufeh Hajsadeghi et al. Which reported decrease in
mean gradient in descending aorta 58% following stenting, the
residual gradient could be the result of changed flow dynamics
along the stent Tan et al. .
However, in some patients, there was an under- or
overestimation of the pressure gradient across the coarctation site
on Doppler echocardiography. As mentioned, these are affected by
other factors, such as cardiac output, lesion length, the presence
of collateral networks, and aortic compliance. Therefore pressure
gradient alone as an index of aortic narrowing is often inadequate.
Although the mean velocity in both the descending and
abdominal aorta significantly decreased after stenting, the
difference was more significant in the descending aorta, with an
approximately 60% reduction. This was matching with Shokoufeh
Hajsadeghi et al. Similarly, the acceleration time in the descending
aorta was different from the corresponding measurement in
the ascending aorta in coarctation. Shaddy RE, Snider AR. This
is manifested clinically by radial femoral delay and diminished
pulses distal to the coarctation. After stent implantation, the
acceleration time showed statistically significant decreases in
both the descending and abdominal aorta.
Based on our findings, the velocity–time integral and time
to peak systolic velocity can be also used as new markers of
significant coarctation. Both indices significantly decreased after
stenting. We also found pressure half-time indices (systolic and
diastolic velocity half-times, systolic and diastolic pressure halftimes)
can be used to assess the severity of coarctation, with
sensitivities of 88 and 84% and specificities of 86 and 89% for
the abdominal aorta and descending aorta, respectively. This is
minimally different from the results of Shokoufeh Hajsadeghi et
al. who reported sensitivities of 87 and 81.8% and specificities
of 100 and 87% for the abdominal aorta and descending aorta,
These findings were in keeping with the results of previous
investigations by Carvalho et al. and Tan et al.  who reported a
significant effect of coarctation of the aorta on these indices.
A study by Lim and Ralston however was in disagreement with
regard to systolic indices. According to Lim, Diastolic velocities
(DVs) and diastolic pressure decays have been shown to provide
invaluable information for assessing the severity of coarctation
Hoadley SD, Duster MC
The index of D/S ratio velocity was first used by Tan et al.
 as a marker of significant coarctation. They demonstrated
that a D/S ratio velocity of >0.53 had a sensitivity of 100% and
specificity of 96% for detecting significant aortic coarctation.
They believed that by correlating diastolic with systolic velocity,
this ratio would be less affected by variations in heart rate, stroke
volume, systemic blood pressure and aortic compliance. Tan et al.
 in our study we found cut-off value of >0.38 for D/S ratio in
descending aorta to has a sensitivity of 88%, specificity of 91.5%
for detecting significant coarctation which was close to D/S ratio
reported by Tan et al.  (0.53), Shokoufeh Hajsadeghi et al.
(0.43 value showed sensitivity 95.7%, specificity 87%).
Whereas the ratio of >0.487 in the abdominal aorta had a
sensitivity of 92% and specificity of 88% in defining significant
coarctation of the aorta. This is close to results of Shokoufeh
Hajsadeghi et al. which reported that ratio of >0.43 in the
abdominal aorta had a sensitivity of 81.8% and specificity of
91.3% in defining significant coarctation of the aorta.
Besides evaluation of the diagnostic value of the
echocardiographic indices, a correlation analysis was also
performed in our study to assess the relationship between the
severity of coarctation before stenting and the echocardiographic
indices. As shown, PHT and VTI of the abdominal aorta and
EDV, EDV, PHT, mean velocity and mean peak gradient of the
descending aorta correlated significantly with the peak gradient
in the coarctation site, measured by catheterisation prior to stent
In addition, the higher pre-stenting gradients were associated
with lower changes in LDV of the abdominal aorta, while changes
in PHT of the abdominal aorta were directly correlated with the
baseline gradient. The observed correlation between the baseline
severity of coarctation and the changes in PHT after stenting
leads us to conclude that this index (PHT) is probably the best
to determine stenting outcome and the probable occurrence of
restenosis. Nevertheless, it should be evaluated in further studies.
The results of the present study showed that a complete set
of Doppler echocardiographic profiles could potentially provide
a valid method to detect success stenting of significant aortic
coarctation. Velocity–time integral, time to peak systolic velocity,
systolic acceleration time and mean velocity were sensitive and
specific enough to detect significant aortic coarctation, as were
peak systolic, early diastolic and late diastolic velocities, pressure
half-time, peak gradient and D/S ratio velocities, which were
validated in previous studies.
To the best of our knowledge this is the second evaluation
of such a complete list of Doppler echocardiographic indices
to detect significant coarctation of the aorta. Our findings
emphasise the advantages of Doppler echocardiography for close
monitoring of patients with aortic coarctation. Although these
echocardiographic indices do improve dramatically in patients
who underwent stenting, they never return to normal values even
if no residual significant stenosis exists (peak pressure gradient
by catheter less than 20mmHg after stenting means no significant
We found a significant difference between pre- and
post-stenting echocardiographic values, Post-stenting
echocardiographic profiles of each patient could therefore
provide an individualised and reliable reference value of his/her
normal aortic haemodynamics, and early detection of restenosis
could be achieved by comparison of post-stenting values with
follow-up values, to our knowledge; there is no follow up study
used these parameters for follow up of patients with coarctation
after stenting, to prove the significance of these parameters to
detect restenosis, however we recommend more studies to use
these parameters for follow up to clarify their significance to
detect restenosis compared to golden standard (cardiac magnetic
resonance imaging or multi-slice computed tomography.