Melanie Cole, MS (Host): Welcome to Better Edge, a
Northwestern Medicine podcast for physicians. I'm Melanie Cole. And joining me
today is Dr. Lubna Choudhury. She's a Professor of Medicine in the Division of
Cardiology at Northwestern Medicine, and she's here to highlight hypertrophic cardiomyopathy
and the treatment and surgical options offered at Northwestern Medicine.

Dr. Choudhury, it's a pleasure to have you join us today. I'd like
you to start by telling us a little bit about hypertrophic cardiomyopathy, the
prevalence, what you see in the trends and your role at Northwestern Medicine.

Lubna Choudhury, MD: Hello, Melanie, and thank you
very much for this opportunity to do this podcast. I'm the Director of the
Hypertrophic Cardiomyopathy Clinic of Northwestern, and I also founded this
clinic back in 2008 with the goal of providing comprehensive multidisciplinary
care for patients with this condition, which can be very diverse in its
manifestations and can require multiple different types of expertise. So, HCM
is a genetic condition where a patient is born with a genetic mutation, which
programs the heart muscle to thicken with time, and it can appear at any time
in your life. And you can have outflow obstruction, which is the most common
form of HCM, obstructive HCM. And obstructive HCM has many treatment options,
and we have all of them at Northwestern.

Melanie Cole, MS: Thank you so much for that. Now,
for providers not used to seeing this, Dr. Choudhury, what symptoms would
indicate a referral as well as the fact that many of the symptoms are similar
to other conditions? Can you speak just a little bit about referral and when
you feel it's important?

Lubna Choudhury, MD: Yes, absolutely. So, you know,
providers who are seeing patients in the community especially should be aware
of symptoms. When a patient says they're short of breath, there is no other
obvious reason. Shortness of breath is a very common symptom. When they do
ordinary activities, they can have chest tightness, heaviness, chest
discomfort. Also, lightheadedness or fainting are very common symptoms of this
condition.

So if a patient presents with that constellation or any of those
symptoms, they may not have all of them, but if they have some of them, think
about hypertrophic cardiomyopathy. Listen to their heart. See if you hear a
heart murmur. Get an ECG and see if the ECG shows left ventricular hypertrophy,
then you know that you're probably dealing with HCM. So then, you should think
about referring them to a cardiologist to do an echocardiogram to confirm the
diagnosis. And of course, if they have HCM, we are known as a center of
excellence for the treatment of this condition, do refer them to us.

Melanie Cole, MS: Well, thank you for that. So,
tell us a little bit about what patients can expect regarding the diagnostic
process for hypertrophic cardiomyopathy and what can they expect from your team
at Northwestern.

Lubna Choudhury, MD: So, the patient can expect, first
of all, that we will ask them for their prior medical records, especially
images of their cardiac MRI or echocardiograms that are recorded on CDs and
sent to us, so we can upload them in our system for our review because we feel
it's very important to make sure that their diagnosis of hypertrophic
cardiomyopathy is actually correct. If we do not have access to those images,
they can expect to have their echo done here at Northwestern. It could also be
a stress echo or a cardiac MRI if they didn't have one done. It is very
important to make the correct diagnosis. I emphasize that as some conditions
can look like HCM, hypertrophic cardiomyopathy, that's the short name for it,
with totally different treatment approaches for them. So, we need to make sure
the diagnosis is correct. The patients can also expect that we do an ECG, which
is an electrocardiogram in the office when we see them for the first time. And
we also offer them genetic testing since this is a genetic disease. We often do
a heart monitor on them, usually for 24 hours, but could be for longer
depending on whether they have palpitations as symptoms or lightheadedness and
so on. So, these are the main tests the patient can expect from us.

Melanie Cole, MS: Well, I'd like you to speak about
treatments, non-surgical and surgical. So, start with non-surgical. What
treatment options are available?

Lubna Choudhury, MD: So, HCM has been treated for many
years by medicines which were initially developed for other heart conditions.
And the most common medicine we use is a beta blocker medicine such as
metoprolol, and this works very well in many patients. We also use
nondihydropyridine calcium channel blockers if people cannot tolerate the beta
blockers. And we also need sometimes a third line agent called disopyramide or
Norpace, which is a particularly hard drug to find these days as it is not
produced as much because it happens to be its only niche use in cardiology.

So, these drugs actually reduce left ventricular outflow tract
obstruction in HCM, which is a feature present in the majority of these
patients and cause their symptoms. So, what I mean by outflow tract obstruction
is that HCM causes the muscle to thicken and the muscle pulls the mitral valve
the wrong way and blocks the blood flow out of the heart. And this causes
obstruction and high pressures in the heart and causes their symptoms. And these
medicines improve their symptoms by reducing this abnormal physiology that we
see in the heart.

Melanie Cole, MS: And if they are refractory to
medicational intervention, what are some of the surgical options available?

Lubna Choudhury, MD: The classic surgery for a
hypertrophic cardiomyopathy patient is called the septal myectomy, which means
that the surgeon does open heart surgery and cuts out a portion of the thick
heart muscle, so that it does not pull the mitral valve the wrong way, and it
widens the outflow tract of the left ventricle so that the blood can flow
freely out of the heart when it pumps without obstruction, thus decreasing the
pressures in the heart.

Apart from this classic surgery, other surgeries that are
available are ways of repairing the mitral valve and the subvalvular apparatus.
The mitral valve, I have to say, is often abnormal in HCM. It's often elongated
and floppy and requires repair. And I would emphasize that we are one of the
few centers in the country that routinely do complex anterior mitral valve
repair, such as resections and folding plasty and papillary muscle
repositioning in conjunction with myectomy to achieve low gradients in patients
with obstructive disease involving the mitral valve apparatus, which consists not
just of the valve leaflets, but also the chords, which anchor the valve
leaflets to the papillary muscles of the left ventricle. And we know that at
least about one-third of patients with obstructive HCM have problems with the
mitral valve apparatus. So, you need surgeons who are able to deal with the
whole problem. And we are also pushing forward the science at Northwestern of
the surgical technique using intracardiac echocardiogram to evaluate the extent
and effectiveness of the resection during myectomy. So, we are looking at the
optimum amount of muscle to be resected and removed that will yield the best
hemodynamic result rather than just enough approach. There is also a team
approach here with surgery for HCM. Dr. Doug Johnston and Dr. Chris Mehta always
review the cases together and do the complex cases together, so that we are not
dependent on a single surgeon to achieve the great results that we have with
surgery.

Melanie Cole, MS: What excites you on the horizon,
Dr. Choudhury, for HCM?

Lubna Choudhury, MD: So, a fundamental problem in
hypertrophic cardiomyopathy is at the level of the heart muscle fibers, where
the muscle fibers are working over time because they're being pulled on by a
large number of hands, so to speak, of their fellow fibers to make the heart
contractility vigorous. And that vigorous contraction is a problem because it
pulls the mitral valve the wrong way and blocks the outflow tract and causes
obstruction.

This abnormal muscle biology was addressed by a designer drug that
was developed for HCM. Northwestern participated in all those drug trials, and
this class of drugs has been approved by the FDA last year and it is called
cardiac myosin inhibitor. The first drug to be approved was mavacamten last
year. And in the majority of patients, this drug showed spectacular improvement
of symptoms by changing the way the heart works. It is very effective at
reducing outflow obstruction that causes the majority of symptoms in this
disease. It is a very exciting time for HCM because close on its heels is
another cardiac myosin inhibitor that we are developing as we speak. And we
have already done some trials with very positive results. And we are going to
do much larger trials using this second generation cardiac myosin inhibitor.
And I'm sure we will have something very exciting to report within the next
year or two.

Melanie Cole, MS: Dr. Choudhury, as we wrap up, and
you've given us so much great information, and you've said that Northwestern
Medicine is a center of excellence for HCM. I'd just like you to summarize
today's episode, what you would like the key takeaways to be and what makes
Northwestern Medicine so uniquely qualified to treat patients with HCM.

Lubna Choudhury, MD: Sure. Fortunately, in
Northwestern, we have deep expertise in the management of hypertrophic
cardiomyopathy. There are people like me who are HCM specialists, who have been
seeing these patients for years and years, and we have a feel for what to do
next for each patient. I think that is important because many of the
cardiologists who refer patients to us really want us to tell them what to do
next, and we are that port of call for you.

In addition to that, we have all the tools we need for diagnosis
and treatment of these patients at Northwestern with an unparalleled
collaboration from a multidisciplinary team consisting of expert surgeons,
electrophysiologists or heart rhythm doctors who treat abnormal heart rhythms
in these patients and implant devices like pacemakers and defibrillators for
those patients who need them, as well as a wealth of experts on cardiac
imaging, reading these MRI and echocardiographic studies.

HCM is a genetic disease. It's caused by a gene mutation. So, we
have cardiovascular genetics experts who are cardiologists who are specializing
in the genetics, and they're available to our patients for consultations once
we get their genetic test results back. We also have genetics counselors for
our patients as well as cardiac behavioral medicine staff to counsel patients
who are very anxious with this disease. We also have access to dieticians
across our health system who can counsel patients regarding nutrition and
weight loss if they need it and so on.

So, we have the pieces in place to deliver comprehensive care for
a patient. So, we are a one-stop shop for HCM at Northwestern because of all
the expertise that has been built up into our program over the years. And as
you know, we have been recognized as a center of excellence by the Hypertrophic
Cardiomyopathy Association for many years. And we do a promotion with patient
information webinars. We did one recently in April. It was well received with
over 300 registrants I'm told. And we also were featured in the April
newsletter of the Hypertrophic Cardiomyopathy Association. Our program was featured
as a center of excellence.

So, we have the reputation because we deliver comprehensive care.
And HCM is a disease with very variable symptoms. Some people have no symptoms.
They see me once a year to check in. Others have lots of symptoms. We end up doing
heart transplant in some of these people and in between our other patients who
are somewhere in between. So, we have something for everyone, no matter what
type of HCM you have. So, I think that's why we are recognized as a center of
excellence.

Melanie Cole, MS: Thank you so much, Dr. Choudhury.
What an informative episode this was. To refer your patient or for more
information, please visit our website at
breakthroughsforphysicians.nm.org/cardiovascular to get connected with one of
our providers. That concludes this episode of Better Edge, a Northwestern
Medicine Podcast for physicians. I'm Melanie Cole. Thanks so much for joining
us today.