(uplifting music)
- Today we'd like to talk about the current management
of aortic stenosis.
And we're going to use the 2020 AHA/ACC
valvular heart disease guidelines
as a background that help guide us
through the current management,
which has changed significantly
over the last decade or decade and a half.
The reason for that is the availability
of a less invasive therapy that has become available
since 2012 in the United States,
and that's TAVR, or transcatheter aortic valve replacement.
As a surgeon, prior to this, we felt that we were operating
and treating all patients with aortic stenosis.
Little did we know that we were only seeing
the tip of the iceberg of the disease.
Now that we have a less invasive approach,
we're seeing a whole new cadre or cohort of patients
that are now candidates for treatment
that previously weren't,
when only invasive surgical aortic valve replacement
was the treatment of patients with severe aortic stenosis.
As a matter of fact, the number of patients
with aortic stenosis that are now being treated
has tripled over the last 10 years,
and there are about twice as many patients
treated with TAVR as they are
with surgical aortic valve replacement in the United States.
The availability of the information
from the randomized trials of TAVR versus surgery has served
to propel this shift in treatment.
Starting with inoperable patients, and then going
through a downward cascade of risk into high surgical risk,
intermediate surgical risk, and low surgical risk patients
has definitely expanded the candidacy of patients
for treatment of severe aortic stenosis.
However, we get the sense that we are still,
even though we're seeing a little more of the iceberg
right now, there's still a huge portion
beneath the surface of patients with aortic stenosis
that we are not treating yet.
And this has to do with the diagnosis,
the access to care, and the lack of knowledge
of the true prevalence of the disease.
For example, we don't know whether aortic stenosis
is as common in Blacks as it is in whites.
We truly don't know current demographics
of male versus female.
So there's a lot of focus now on determining
the true prevalence of the disease and facilitating access
to care, especially in underserved minority populations.
One of the things that we are finding
is that it's not unusual or unheard of for an echo
to be ordered and no follow-up occurring on that echo.
So we're finding that there's patients
that are actually been diagnosed with severe aortic stenosis
or severe mitral regurgitation,
that have fallen through the cracks,
that don't get follow up.
There are multiple triggers that we're trying to put
into EHRs to help flag these abnormal studies.
And echo labs are are doing this,
but it's absolutely critical that once a test is ordered,
there's a trigger to be sure to follow up on those tests
so that the patients that do have valvular heart disease
are not lost through the cracks
and follow up actually occurs.
So the guidelines give us recommendations
of how to evaluate patients
with suspected valvular heart disease.
And of course the initial history and physical
is key in terms of determining symptoms,
be it heart failure syncope, chest pain, other signs
of aortic stenosis or other valvular heart disease.
Current guidelines recommending stages of aortic stenosis,
of A, B, C, and D.
Stage A is patients who are at risk for aortic stenosis.
So somebody with bicuspid aortic valvular disease
would be an example of that.
Stage B is progressive aortic stenosis.
So this would be somebody with mild
or moderate aortic stenosis that is progressing presumably
at some point towards severe.
Stage C is patients
with asymptomatic severe aortic stenosis.
So the aortic stenosis is severe,
but the patient doesn't have symptoms.
Now it's interesting that patients
with asymptomatic aortic stenosis,
in our evaluation of them,
only about half the time are truly asymptomatic.
It is appropriate to stress-test these patients,
and about half of patients will actually have
a significantly abnormal exercise tolerance test
when based upon even on the most diligent history
ahead of time the patient appears to be asymptomatic.
And finally, stage D is patients
with severe symptomatic aortic stenosis,
where treatment should be further considered.
So in summary, we have four stages, A, B, C, and D,
on the basis of symptoms, valve anatomy, severity
of valve dysfunction, and the response of the ventricle
and pulmonary circulation to a valvular heart disease.
Now, the evaluation of a patient with known
or suspected valvular heart disease initially, of course,
starts with the history and physical examination.
If it is suspected that the patient has significant
or valvular heart disease,
the next step is a transthoracic echo.
In a transthoracic echo what you're looking for
is the presence of valvular heart disease,
the severity of valvular heart disease,
and any consequences of valvular heart disease,
including left ventricular function
or pulmonary hypertension.
Probably the next most important one is the CT scan.
And the CT scan should evaluate not only the heart
and valve itself, they should undergo 3D reconstruction
to determine the particular anatomy
of the aortic valve, ascending aorta,
as well as peripheral access information,
in order to determine whether the patient is a candidacy
for transfemoral access for the TAVR procedure.
Now, this is important to do
even if the patient is a candidate for surgery
and not for TAVR.
CT scan evaluation of the heart aorta
and peripheral arteries are critical,
even if a patient's undergoing surgery rather than TAVR.
So once the decision's made that the patient is a candidate
for therapy, CT evaluation is next appropriate.
Cardiac MR can be very helpful,
especially in low cardiac output stages,
in determining left ventricular function
or left ventricular damage from the valvular heart disease.
Biomarkers, specifically B and P, can be helpful
in terms of evaluating.
Finally, if the severity of the valvular heart disease
is not determined, left and right heart catheterization
can add significantly to it.
Now, clinical decision-making regarding the treatment
of aortic stenosis is best performed
by a heart team approach.
The guidelines recommending evaluation by patients
at valve centers of excellence, where a patient is seen
by a multidisciplinary heart team, which consists
of at least an interventional structural cardiologist
as well as a cardiac surgeon
with expertise in valvular heart disease.
There's frequently many other members of the team
that are valuable in terms of evaluating of the patient,
including imaging specialists, gerontologists,
mid-level providers, research coordinators.
The decision should be shared decision-making
of the caregivers, the patient, and the patient's family
determining what factors are important in the patient,
what the expectations of therapy are,
and what matters most to a patient.
Oftentimes, longevity of life is not the primary goal
of therapy for patients,
and sometimes it's improved quality of life,
even though life may not be prolonged by the therapy.
Throughout the surgical treatment of aortic stenosis
and throughout the trials, the decision-making was all based
upon surgical risk, and the STS surgical risk score
was used to profile these patients.
What we see now is a shift in the guideline recommendations,
as the decision is now based on age rather than risk per se.
And I think it can be distilled down very simply.
The first decision to be made, is the patient a candidate
for a tissue or a mechanical valve?
And this is based primarily on age.
Patients that are under 55 to 60 years old
should be considered for either a mechanical valve
or a Ross procedure as a best treatment option for them.
Once you're out of this age range and the decision is made
for tissue rather than mechanical,
then the age factor is very important.
If you're under 65 years old,
the treatment probably most commonly should be surgery.
That's on the basis of the fact
that these were the only patients that were included
in the randomized trials, and we don't know valve durability
of how long a valve is going to last.
Also, there's a higher incidence
of bicuspid aortic valve disease
in patients under 65 years old,
and patients with bicuspid aortic valve disease
were not included in the trials.
So surgery is a class 1 recommendation
in patients under 65 years old.
If we go to patients over 80 years old at the other end
of the spectrum, then TAVR is the preferred treatment.
Even though the outcomes with surgery
are the same as with TAVR in older patients,
if you have two therapies and one is less invasive
than the other, then the less invasive therapy
is the preferred treatment by both patients
and their referring caregivers.
And so we know that TAVR is less invasive than surgery,
the outcomes are the same.
Therefore, class 1 recommendation in patients
over 80 years old is transcatheter aortic valve replacement,
with surgery being an option if the patient
has particular issues with the anatomy of their valve
or high risk for TAVR for any particular reason.
In patients between the ages of 65 and 80,
both surgery and TAVR are class 1 recommendations.
And again, this is where shared decision-making
with the patient and their family is crucial.
Both surgery and TAVR are good options
in patients who have systemic disease.
So for instance, frailty, multiple comorbidities,
or at increased surgical risk, TAVI would be the answer.
If patients have anatomical features
of the aortic stenosis that make them high risk for TAVI,
then surgery is the proper.
And patients that would be high risk for TAVI or TAVR
include excessive bulky calcification,
calcification going into the left ventricular outflow track,
patients that are at risk for coronary obstruction.
In patients where they have equal risk for both procedures,
more often than not the patient and their family will choose
the less invasive option, and therefore TAVR.
If there are other comorbidities or other valvular
or other heart disease present,
such as coronary artery disease, mitral regurgitation,
et cetera, then the decision should be made
on the basis of that disease.
So in other words, if you have coronary artery disease
and the treatment recommendation was going to be CABG,
then that patient should probably get an AVR plus CABG.
If on the other hand, that patient's coronary disease
can be treated with PCI, then a staged TAVR plus PCI
would be the preferred option.
I think we can summarize this whole area
of clinical decision-making in patients
with severe aortic stenosis as follows.
The indications for transcatheter aortic valve replacement
are expanding as we have had multiple randomized trials
that have shown the benefit
of transcatheter aortic replacement,
compared to surgical aortic replacement.
The choice of the decision in a particular patient
is a shared decision-making process
that includes the lifetime risks,
as well as the benefits associated
with the type of valve being used.
In younger patients, mechanical valve or the Ross procedure.
In patients under 65,
probably surgical aortic valve replacement.
And then above age 65, a strong consideration for TAVI.
Now, once a patient receives treatment,
especially with a bioprosthetic valve,
be it surgery or TAVR, they need to be followed up
on a regular basis.
And a baseline transthoracic echo at 30 days
after the procedure is the cohort of therapy for both.
Patients should then have a second transthoracic echo
at the first year afterwards,
and then every two to three years following that.
If there is any concerns about postoperative problems
or complications, such as periprosthetic valve leak
or valve thrombosis, then more invasive imaging
including 4D CT scan is indicated.
We can summarize the whole field as follows.
The availability of TAVR has expanded
the number of patients for aortic valve stenosis,
and I think we'll continue to expand it significantly
in the years to come.
As diagnostic testing becomes more widely available,
as the efforts at increasing access to care
for underserved minority populations increases,
as we have testing to determine the true prevalence
of the disease, I think we will see more and more patients
diagnosed with aortic stenosis.
The evaluation of treatments should be
a shared decision-making process with the patient,
including a multidisciplinary heart team,
preferably in a valve center of excellence.
That includes not only the caregivers,
but also the patient and the patient's family,
and including the patient's primary cardiologist.
Very frequently what we find
is that a patient has been cared for
by a cardiologist for 10, 12, 14 years,
and then develops severe aortic stenosis
is referred into therapy.
It is critical that that caregiver be included
in the shared decision-making process,
'cause nobody understands the patients
and the patient's preferences better than that physician
who's been caring for them for a number of years.
So inclusion of the patient's primary cardiologist
is a critical part of the decision making
for the treatment of a aortic stenosis.
And lastly, there's a lot of interest
in therapies that would slow the progression
of aortic stenosis.
Over decades now of looking for pharmacologic agents
that may slow the progression, so far,
none have been successful in terms
of slowing the progression, but developing new trials
and new trial platforms which have been bought out
of the COVID trial evaluation era may help us
find an answer to slow the progression of aortic stenosis.
So this is an exciting time
in the treatment of aortic stenosis.
TAVR has been a significant sentinel event and watershed
in terms of treatment, but this is not the end
of the story on the treatment of aortic stenosis.
Rather, it's the end of the beginning of the story
of treatment aortic stenosis,
with many exciting things to come in the near future.
(gentle music)