JIM Today 2018 - Saturday - page 10

10
JIM today
Issue 3 
Saturday
 24 February 2018
Calcific lesion preparation: the role of imaging
I
ntracoronary imaging was laid
bare on Thursday at JIM, during a
session that included discussion of
imaging in calcific lesions, vulner-
able patients, and stent optimisation.
Opening the session was Carlo Di
Mario (Careggi University Hospital,
Florence, Italy), who focussed on the
two main modalities widely avail-
able in modern day cath labs: IVUS
and OCT.
Speaking to
JIM Today
, Dr Di
Mario noted the fundamental dif-
ferences in the way IVUS and OCT
assess calcium: “When calcium is
treated with Rotablator [Boston
Scientific, USA] or cutting/scoring
balloons, OCT is able to detect the
small cracks and fractures much
better than IVUS, and assess the
distance of struts to the wall in the
frequent case of stent malapposi-
tion along the irregular non-circular
lumen surrounded by protruding
calcium. But having stated these
advantages of OCT, let me clarify
that both IVUS and OCT can provide
the essential information on the
circular and longitudinal extent of
calcification, and in fact IVUS is more
reliable in case of deep calcium that
can be missed with OCT due to its
limited penetration.”
Calcified lesions are frequent in
atherosclerosis but become truly
prevalent in older patients, and in
those with diabetes or renal insuf-
ficiency. Severely calcified lesions are a
risk factor for stent failure, even in the
drug-eluting stent era. What imaging
has brought to the understanding of
the impact of this pathophysiological
process, explained Dr Di Mario, is an
improved appreciation of the sig-
nificance of under-expansion below
the dangerous absolute threshold of
5.0-5.5 mm
2
, and poor stent apposi-
tion (with struts very far from the
wall, situated in the elliptical irregular
lumens present when a large calcific
plaque remains protruded).
Dr Di Mario also spoke of optimal
lesion preparation: “It is an exciting
time for operators that are chal-
lenging heavily calcified lesions,” he
commented. “In the past Rotabla-
tor – or, in the United States, orbital
atherectomy – were used to deal with
uncrossable/undilatable lesions. Some
operators, after these initial passes,
were using cutting or
scoring balloons, con-
centrating the force
of the balloon on the
blade/wire in contact
with the wall.
“The majority of
cases were treated
just with brutal force,
increasing the diameter
and pressure of the bal-
loon until the wall was
giving up, and sometimes too much,
leading to perforation. The presence of
calcium at angiography/fluoroscopy is
not enough for an informed decision
on the need to use dedicated calcium
ablation systems, nor the selection
of type of device. Results were often
suboptimal, despite the use of these
cumbersome techniques guided by
intracoronary imaging.”
He continued: “We now have
a novel method to crack calcium
inside the wall, with no risk of
microembolisation and slow
flow, as easy as the insertion of
a normal balloon. Lithotripsy has
the potential to revolutionise and
simplify our approach to treatment
of calcific lesions.”
Asked what evidence currently
supports the use of imaging in the
accurate assessment of accumula-
tion and distribution of calcium, and
the effect this has on procedural
outcomes, Dr Di Mario responded:
“We do not have convincing evidence
in general that imaging modalities
truly make a difference in outcome
after PCI.
“For calcified lesions, we can
certainly help in selecting the most
appropriate size or type of device,
but we are not always able to ensure
full expansion.”
Imaging is very good at show-
ing the problem, he went on, but it
does not mean that one is necessar-
ily able to solve it. “With lithotripsy
everything may change,” he said. “It
will be worthwhile to use imaging
to ensure we apply these expensive
balloons only when we truly need
them, and select balloons large
enough to be in contact with the
wall, and to transmit the shock-
waves – a prerequisite for effective
calcium fragmentation.
“The rest should come easier,
but it is reassuring to see calcium
fractures more often, and see a more
circular larger lumen with better
strut apposition.”
Intracoronary imaging 
Parini 
Thursday 
12:45
“Both IVUS and
OCT can provide the
essential information on
circular and longitudinal
extent of calcification.”
Carlo Di Mario
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