CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 9, October 2012
AFRICA
489
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.
Although our study had some limitations, including small
sample size, no long-term follow up and no CMR imaging for
evaluation of the aortic coarctation index, it had some findings
which have not been reported before. One must also consider the
problem of using a functional technique to predict anatomical
obstruction, especially in adults where the haemodynamics are
directly and significantly affected by the presence and extent
of collateral blood flow. Doppler techniques are more valuable
in neonates with coarctation, where collateral flow has not had
time to develop, and the haemodynamic consequences are more
clearly related to the anatomical obstruction.
The results of the present study showed that a complete set
of Doppler echocardiographic profiles could potentially provide
a valid method to diagnose 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 velocity, which were
validated in previous studies.
To the best of our knowledge this is the first 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 undergo stenting, they never return to normal values even if
no residual stenosis exists.
Conclusion
We found a significant difference between pre- and post-stenting
echocardiographic values, which could provide valuable insight
for evaluation of follow up and response to treatment in patients
with aortic coarctation. 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. A similar clinical
approach is used in echocardiographic follow up of patients with
prosthetic heart valves.
39
We suggest that these echocardiographic indices could be
used as reliable detectors of the patient’s response to treatment,
and their predictive role in the follow up of these patients is
obvious. However, in order to evaluate recurrent stenosis, it
would be important to re-evaluate patients during longer-term
follow up, which could be undertaken in further studies.
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