HCM Forum: Cardiomyopathy In Disguise

- [Woman] On behalf of the American Heart Association, I would like to welcome you to this session, "The Cardiomyopathy in Disguise." Throughout this session, you will have the opportunity to submit text questions for our speaker using the questions feature on your control panel. You may send in your questions at any time and we'll review those questions during our Q&A at the end of the presentation as time allows. To access live closed captions, please click on the closed caption button found o

n your screen. All sessions will be recorded and available in the coming weeks. It is my pleasure to welcome our speaker for this session, Nancy Robles. Nancy is a nurse practitioner at the Stanford Center of Inherited Cardiovascular Disease. As a reminder, full speaker bios can be found in the event lobby. Nancy, the floor is yours. - Good morning, it is my pleasure to meet you all and talk about hypertrophic cardiomyopathy. No disclosures. And this is often called "The Cardiomyopathy in Disgui

se" and we will review why it's often undiagnosed or missed. I have experience at the Center for Inherited Cardiovascular Disease over the past eight years. So we'll begin with just the basic definition of cardiomyopathy just as a refresher. Cardiomyopathy refers to an abnormality of the heart muscle that can alter function and morphology. A primary cardiomyopathy is an inherited cardiomyopathy. Some examples of that, often when we don't know which inherited cardiomyopathy, we call it nonischemi

c cardiomyopathy and then we have dilated cardiomyopathy, non-compaction cardiomyopathy, and what we're talking about today, hypertrophic cardiomyopathy. A secondary cardiomyopathy is a cardiomyopathy that you acquire secondary to another disease. Some examples are going to be substance abuse, ischemic cardiomyopathy which is after heart attack damage, muscular dystrophy because it affects the muscles and your heart is a muscle, and amyloid doses which most people don't know about, but here at S

tanford we do because we specialize in it. So as an overview, HCM can be related to mutation of genes that lead to abnormal structure of the sarcomeres. Some well-known mutations to cause HCM are in genes MYH7, MYBPC3, TIN 3, and TNNT2. When you look at an HCM cell or sample under a microscope, what you see is myocyte disarray, fibrosis which means scarring, and hypertrophy. HCM is autosomal dominant which means that if your parent has it, you're at 50% chance of having it. If you have it, your

child has at 50% chance of having it as well. Morphology and genetic abnormalities do not always correlate. So this is what makes it very difficult and it's kind of hiding because you could have different morphology and symptoms in the same family. Defining hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy is diagnosed when you have left ventricular hypertrophy that is not explained by other conditions. That can also cause increased well thickness. Some examples of those conditions are lo

ngstanding hypertension. People that have not managed their blood pressure well for a long time will show hypertrophy. It's just the heart's response to remodeling. Athletic remodeling is also in elite athletes, competitive athletes, Olympians. You can see that the heart gets thick, but it's a benign thickness. It's just what we call athletic remodeling. Infiltrative diseases like amyloid and sarcoid which are less known. Also the maximum wall thickness should be greater than 15 millimeters. Unl

ess you have a first degree family member that has a diagnosis of HCM, then it would be a wall thickness greater than 13 millimeters. So as I said, HCM is a genetic condition. First degree relatives are at 50% chance of inheriting it. Diagnosis, the way we diagnose is the circular pathway. We diagnose, we manage, and then we follow up and each time we do pretty much the same process. So we began evaluation by history of symptoms. We go back even to childhood and that can often give us red flags

that this has been there for a while. A good medical history to rule out other conditions. A medication history, vital signs, and then advanced cardiovascular examination and advanced cardiovascular examination can be very helpful because you can hear a murmur sometimes. Diagnostics, what do we use? Basic EKG, your EKG can show voltage abnormalities, repolarization abnormalities, and even T-wave inversions. Echocardiogram is the gold standard for HCM screening. We also do a CPET or CPX which is

a cardiopulmonary exercise test to evaluate for obstruction, LVOT obstruction that may not be seen at rest or with Valsalva. Heart MRI is very helpful in defining morphology with more detail than echo and also to get a better estimate of the wall thickness. Another important reason to do an MRI is to assess for DGE, delayed gadolinium enhancement, that shows fibrosis or scarring and that is important to know because that increases the risk for arrhythmia. Labs, we do a baseline troponin NT-proBN

P and that's just to have as a baseline. But often in HCM, these are going to be elevated and so you have these patients that have an abnormal EKG, inverted T waves, and elevated troponin, so they're often in the ER for chest pain and they get worked up for MI when in fact it's HCM. You would think biopsy would be slam dunk, but it depends on what part of the muscle you're targeting. So if you're targeting an area that has no hypertrophy, you won't see it. Genetic testing can be very helpful in

identifying known variants. However sometimes we do not identify a variant, but when we do, it's very helpful because you can use that to screen family members. So why should we know more about HCM? Why are we doing this? Well, actually it's very common and most people are undiagnosed or misdiagnosed. So the prevalence is estimated to be 1:500, but we think it's actually 1:200 because we have all those people out there with no diagnosis yet or misdiagnosed with asthma, and so the disease severit

y can also range from asymptomatic to possible heart failure. Atrial fibrillation sometimes it's the first sign because of left atrial enlargement that occurs as a result of high pressure in the left ventricle. Sudden death can also be the first sign or a sign of disease, and we have some patients have had cardiac arrest and some patients that don't so. And HCM affects all genders, all races and ethnicities including Black, Asian, American Indian, white, and it actually is very common in many co

untries. At least 125 countries in all continents worldwide. So what are these symptoms and why are they so difficult to diagnose? And that's why we call it a cardiomyopathy in disguise, so let's look at these symptoms. Asthma, physical deconditioning, angina, syncope, atrial fibrillation, sleep apnea. Sometimes the first symptom is sudden death as I mentioned, but often it's asymptomatic. So if you see any of the symptoms, HCM is gonna not gonna be on your radar most times. And that is because

of these symptoms are very common. Patients will go into the ER for chest pain and if they're young and they look healthy, they may not even get an EKG. Shortness of breath with exertion is a common limitation. Fatigue, dizziness, difficulty doing exercise, and fainting. Fainting usually occurs because of LVOT obstruction or because of arrhythmia. So you can see that someone that presented with these symptoms into the ER might be diagnosed with anemia, anxiety, and many other non-HCM diagnoses.

So how do we approach care? We do an evaluation to find out if there's symptoms, if there's arrhythmia, if there's obstruction, LVOT obstruction. Part of the initial evaluation is actually talking about the risk of sudden death and we have tools to estimate the patient's risk for sudden death and educate them about that. And red flags for higher risk for sudden death include a past cardiac arrest, passing out, and having very severe disease. So we do tell patients hey, we think you have this app

roximate level of risk for sudden death. In cases, we talk about ICD and the patients can do that for primary prevention of sudden death. Treatments vary from medications to surgical procedures. Traditional therapy include beta blockers and calcium channel blockers. Novel therapies include cardiac myosin inhibitors which have been shown to be very effective and symptomatic HCM with obstruction. More advanced interventions include surgical procedures like a surgical myectomy. So why should we all

have more awareness of this condition? And that is because these patients don't see the cardiology team first. They'll actually see their primary care doctor quite often. They'll often see their OBGYN. They'll often go to the pediatrician and those providers are the first contact with patients. So they're the ones that can these subtle signs and if they're not sure, we always say lean on the side of caution and ask more. Do a family history. Family history can often reveal red flags even when a

patient's not symptomatic. We really encourage primary care first line providers to refer to cardiology if you have any concerns or a screen with EKG. If EKG is abnormal, you can do an echo and if you don't know, you're not sure, just refer to cardiology and a center of excellence, HCM specialists specifically because they can help rule out or rule in, and we don't mind that. We don't mind all sorts of referrals. So currently there are gaps in awareness as we discussed. Access to care is huge a

lso because you may have patients with symptoms out there but they don't have coverage, financial coverage for their care, so they don't get an EKG, they don't get an echo, and in the meantime disease can progress. Delay in recognition, if you've been diagnosed with childhood asthma, for example, your inhalers don't work and you just kind of give up and don't exercise, that's a diagnosis that was delayed and misdiagnosed obviously. Also the prevalence is underestimated. When we go out in the com

munity and we talk about it, providers may say, "I don't have patients with HCM." When in fact, it's 1:200. If we estimated 1:200, that's pretty common and it's probably 'cause these patients are undiagnosed or misdiagnosed. So recommendations from us are increased awareness, education, reminder to obtain a family history because that sometimes is what's gonna lead you to screening and diagnosis. Have a low threshold to screen and if there's any doubt, don't hesitate to transfer, to refer to a c

enter of excellence. Thank you very much. - [Woman] Thank you, Nancy, for that great presentation. It looks like we have time for a few questions. Question number one, given that HCM can present so variably, what are some high yield action items we can do at our own institutions to increase awareness and diagnosis of the condition? - Yeah, great, include it in your differential. If you have any of those symptoms that we review today, include it in your differential. If you think it's asthma, if

you think it's a lone AFib because the patient's old. Think of HCM in your diagnosis and that alone will help you. - [Woman] Thank you, question number two. Hi, I'm a 28-year-old female and my mother's father died of HCM at 45 years old. Should I be evaluated by a cardiologist? My mother is followed by a cardiologist and has not been diagnosed with HCM, thank you. - I don't know if there's genetic testing involved here. If there isn't, yes, you should be screened because you still have a chance

of having it. If your mom hasn't been, it could be that her disease is very mild. If she gets genetic testing and a variant is found, then that can be really helpful for you because you can look for that same variant. But you should have an EKG and echocardiogram at least once in your life. - [Woman] Thank you, question number three. Can you comment on the stigma phase by these patients? I imagine some of these symptoms can be labeled as lazy. - Yeah, lazy deconditioning, and most times patients

will say, "I don't have any symptoms." And that is because since they were young, they have just not exercise because they can't and they just assume I'm not a great runner, or I'm not, I don't like hills, I don't like hiking. And so that gets, one example is asthma. We see that a lot. But if you have a patient showing up to your office with some of these symptoms, you might say, "Oh, well it could be anemia." "Oh, well it could be a heart attack," Could be anxiety even especially because a lot

of these patients are young, and they look good, and they look healthy. - [Woman] Thank you. Those are all the questions we received for this session. Thank you, Nancy, for a wonderful presentation and thank you to our audience for your participation. - Thank you. - [Woman] Coming up next, no problem. Coming up next at 10:45 Central, we have "From Clinician to Patient: A Physician's HCM Journey." To access, please exit this session and return to the lobby using the menu at the top of your scree

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