I'd like to welcome
our audience and listeners today for
another session of interview
with the experts by Malcolm Belinda,
vice chair for the department
of cardiovascular medicine.
And I'm really pleased to
introduce and welcome Dr. Anand,
who's an assistant professor of medicine and
apartments in
a specialist in pulmonary hypertension.
So welcome, Dr. Anand.
Thank you so much for having me.
It's a pleasure to be here.
Good.
Well, we're here today to talk
about thromboembolic pulmonary hypertension.
Then they go just have you just
lead off and tell us what exactly this is.
It's a relatively new term
and the last few years,
but something's becoming more commonly used.
If you could just explain what it is and
then pepsin go on
and tell us how you would diagnose this.
Chronic thromboembolic pulmonary hypertension
is a type of precapillary
Pulmonary Hypertension.
When there is elevated thyroid
artery pressures more than 20
millimeter mercury.
We vascular resistance is
more than three would unit with
normally pulmonary capillary wedge pressure.
And chronic thromboembolic pulmonary
hypertension is
caused by chronic pulmonary emboli
at that form, organized scar.
And in setting up
a diagnosis of pre
capillary pulmonary hypertension,
It's usually diagnosed when there are
mismatched ventilation profusion defects
noted on ventilation profusion scan.
It is a challenging diagnosis and
a high index of suspicion
is needed to diagnose this.
But it's getting, we are finding
more and more patients
with chronic thromboembolic pH,
particularly at centers such as ours,
which is a center of
excellence and expertise.
It is diagnosed, as I said,
by a VQ scan,
but the suspicion comes
early on when patients present with
exertional dyspnea or exercise intolerance
as a part of routine work-up.
A chest x-ray and ECG are
performed which are usually non-specific.
Ecg can show evidence of
right ventricular hypertrophy or
enlargement similarity chest x-ray
can show enlarge pulmonary arteries,
right-sided chamber enlargement,
and echocardiogram that auto
would lead to suspicion
or confirmation of pulmonary hypertension.
Once the diagnosis is established,
it's important to evaluate
every patient unless there is
a clear cut other cause of
precapillary Pulmonary Hypertension with
the ventilation profusion scan.
There are some markers on
physical examination that can be helpful,
but often the physical examination signs
are similar to any other cause
of pulmonary hypertension,
such as loud P2,
right-sided chamber enlargement as
evidenced by RV lift,
right-sided third, heart sound.
And if there is development of RV failure,
patient may have signs of
far we failures such as elevated JVP,
lower extremity edema ascites,
or hepatomegaly.
Sometimes we can auscultate a brewery and
the pulmonary brewery
of pulmonary arteries and
the area of stenosis
because of turbulent flow,
which can be a clue to this diagnosis.
So many of those signs
obviously would be seen in
other patients with
undifferentiated pulmonary hypertension
as a first presentation.
What makes you suspicious
in those patients who
come with undifferentiated,
probably hypertension, that this may be
chronic thromboembolic
pulmonary hypertension.
And how many of these patients that you
see have
a prior history of pulmonary embolism?
That's a great question.
So after the diagnosis
of pulmonary hypertension is
confirmed by echocardiography or
suspected on echocardiography.
A right heart catheterization
is usually performed
and that gives a diagnosis
of pre capillary pulmonary hypertension.
And here at Mayo Clinic,
pretty much all patients with
precapillary Pulmonary Hypertension with
the screen with ventilation profusion scan,
which is way more sensitive
than CTN geography because
the lesions may be distal and may not
be evident done on CT angiogram.
And a lot of the times,
actually a quarter of
the times patients do not
have a prior history of pulmonary embolism.
So large registry data has
shown that about 2.3%
patients with acute pulmonary emboli
that they eventually develop
chronic thromboembolic pH.
But Aquadro, the patients
with chronic thromboembolic ph
have no prior history
of PE or pulmonary embolism.
So a high index of suspicion is
is needed to diagnose this condition.
There are some risk associations
that have been studies such
as antiphospholipid syndrome,
prior malignancy,
splenectomy or ventricular arterial shunts
that when present are considered strongest,
strongly associated, but nonetheless.
We have a very low threshold of screening
our patients that capillary
pulmonary hypertension,
that the ventilation profusion scan.
And if the diagnosis is
suspicious or confirmed on VQ scan,
those patients should immediately be referred
to an expert center such as ours there,
the next steps regarding
treatment can be decided on.
Okay, so just before we talk
about treatment and
I know you're gonna be very excited
to tell us about this.
So let me just make
sure I listeners get this.
You stress the importance
of the V-Q lung scan.
Is that something that you
do before they have
cardiac catheterization or only if
they have
precapillary Pulmonary Hypertension.
We typically perform it
either before or after.
And again, it depends
on the clinical context.
So a number of times
echocardiography is very compelling,
are very telling that this patient
has severe pulmonary hypertension.
And B do not suspect
left-sided heart disease or
group to pulmonary hypertension.
And in that case, we will
just order it and a number of times
just for convenience of scheduling
even before a right heart catheterization.
But other times if
the diagnosis is not clear and we suspect
that the patient may
have left-sided heart disease
than it's performed after
the right heart catheterization.
So you've made the point also that
the VQ scan is going to be more
sensitive than a CT scan.
And I think that's an important thing
for our listeners here.
So let's now say that the patient
has precapillary Pulmonary Hypertension
proven a cardiac cath.
They have an abnormal VQ scan.
What's the next step there?
Is there a medical treatment that
you would institute or would
you look to move to something more
invasive or more confirmatory?
Do we do a pulmonary angiogram
is then we do a CT scan.
Tell us what the next steps would be.
Like I said, once the diagnosis
is suspected or confirmed,
patient should be referred
to the Center of Excellence.
And it's important because a number of
times patients are managed
by both medical and surgical approach.
And pulmonary and art director B
can actually be curative.
And some of the patients who
are candidates for the same
after the diagnosis is
suspected or on VQ scan.
The next step, like you mentioned,
is to perform an angiography.
It's invasive pulmonary angiography,
which is again,
I would emphasize needs to be performed in
a center of excellence or expertise.
And it can be performed either by
Dinah CT or digital subtraction.
Angiography and biplane imaging
is typically performed because lung
is a three-dimensional structure to
identify the location and
extent of these lesions.
And once that's performed,
patients are usually evaluated in
a multi-disciplinary team to
discuss if they may be
candidate for pulmonary endarterectomy and if
they're not because of
inoperable distal disease,
are associated co-morbidities or
if they have residue or
recurrent disease after
pulmonary endarterectomy there,
then they are considered
for another catheter-based option
that is now available,
balloon pulmonary angioplasty.
And a number of times before
their patients are considered
for surgical options,
they are treated medically,
but pulmonary vasodilator therapy,
which is important,
especially if the mean
pulmonary artery pressures are
over 3035 millimeter mercury.
And the drug that is FDA approved
is Rio sagwa does a pulmonary vasodilator.
There are some other pulmonary vasodilators
that I sometimes
use besides real cigarette
or you shouldn't, but the Rio squad.
But that is one that
is typically our patients
are started on and we can start
to anticoagulants at that point as well?
Yes. Typically when patients
are diagnosed either they're
already on oral anticoagulant therapy
because of prior history of PE.
But if they're not, they are started on
oral anticoagulants and to reduce
the risk of further pulmonary emboli.
You've talked about
pulmonary artery endarterectomy.
I'm in a surgical approach
versus catheter approach.
In your experience, what proportion
of patients will end up having surgery?
What proportion wanted to
have a balloon angioplasty,
and what proportion would
just be treated medically?
So about 30 to 40% patients are not
candidates for pulmonary endarterectomy
even though it's considered curative.
So it's very important that
more than a third patients
may not be candidates.
And again, some of the reasons are
either the diseases inoperable,
patients are high surgical risk or
the residue ulnar recurrent disease
despite pulmonary endarterectomy.
And sometimes it's patient preference to a
wide a major surgery
such as endarterectomy and.
That's when they're considered
for balloon pulmonary angioplasty,
which has now emerged
as a percutaneous safe option,
but low risk of complication
in these patients who may not be
candidates or prefer not to have by
minority endarterectomy in terms of
medical therapy up in our experience,
most of these patients are on
medical Caribbean and retreat them.
Both medical therapy
and surgical intervention,
either binary endarterectomy or
balloon angioplasty if they
are candidates for either are.
I think
the pulmonary angioplasty is something
really, really keen interests.
Could you just briefly
summarize what the success rate?
So with that, you talked
about low complication rates.
How low is that complication rate?
And as I said, what is the success rates?
Yeah, Great question.
I wanted to take a little dive into
history before I answered that question.
So balloon pulmonary angioplasty procedure,
though, experience of that is
very limited in North America.
It was, the first report
comes from 2001 by Dr.
Feinstein who showed improvement in
hemodynamics and patient symptoms.
And objective in terms of n by at
your function class improvement
and walk distance improvement.
At that time, there was
very high risk of reprofusion injury,
about 60% patient and
about 20% patients
required mechanical ventilation.
The operative mortality is
also high, around 6%.
So this procedure was pretty much
abandoned until it was
tried again in Japan and
centers in Europe using a modified technique.
They're stage operation
or stage procedures were
performed and see
the delegation over multiple sessions.
And we published
our first contemporary North
American experience in 2019.
Often somewhat modified technique,
even slightly modified than
what's used in Japan,
where a few lesions were dilated maximally,
but only a few at a
time and multiple sessions were performed,
so it was performed at a stage manner.
And in our experience,
we published our interim analysis
in 2019, including 31 patients.
26 had inoperable disease and
five head residue l, or recurrent disease.
We noted a significant improvement in
main pulmonary artery pressures even
after an average of about three sessions.
Due to three sessions.
Meantime, artery pressures dropped from
40 to 29 in our cohort.
And pulmonary vascular
resistance decrease from
5.5 would unit to 3.3 volt unit.
There was also significant improvement
and patient's symptoms,
about 60% patients had
improvement in VO2 function class.
The walk distance improved
by about 40 meters.
And echocardiographic parameters of
RB function also improved significantly.
And the procedure was acceptably safe and
there were complications,
significant complications,
and only about three out of 75 procedures,
patient developed hemoptysis
requiring ICU stay overnight.
In other patient had
significant reprofusion injury that
required mechanical ventilation,
but he was discharged and
ultimately passed away within 30 days.
So that was counted under
our mortality, 30-day mortality.
And the code patient had cardiac tamponade,
but he also had a PCI
and had was on clopidogrel.
And those are the only three subjects,
patients out of 75 procedures.
So we reported a significant
both objective and subjective improvement,
improvement and hemodynamics,
patient's symptoms,
as well as very low risk of complication.
Well, I certainly want to
thank you and your colleagues
for the success that
you've enjoyed with these patients.
And it does sounds like some patients
will need a second or
even a third procedure based
on those numbers you just gave.
But just to summarize then
these patients that
present with pulmonary hypertension
have a high index of suspicion.
You emphasize the importance of the VQ scan,
the cardiac cath, and now that sort of thing,
the subsequent imaging and then the
therapeutic invasive
approaches that you described,
both surgery and balloon angioplasty.
Is there anything else you'd
like to add at this point?
We just got a few
seconds before we have to wrap this up.
Yes. You summarized it very
nicely and I would just say that
there should be high index of
suspicion and VQ scan should be
performed in
patients with
precapillary Pulmonary Hypertension.
And once the diagnosis
is suspected or confirmed,
they should be referred
to centers of expertise so that
they can be treated with one of
these surgical options if
they are candidates for the same.
Well, this has been
a very helpful Discussion doctrine
and I'm sure our listeners
and audience were really appreciate this.
And I think clearly
these patients need to be identified.
And as you say,
if there is suspicion or proven
their diagnosis to consider
referral to a center of excellence.
So thank you again very much for
your time and joining us today.
Thank you so much for having me.