Transcription:
What Role Does Genetic Testing Play in Cardiovascular Care?

Melanie Cole: Welcome to Better Edge, a Northwestern Medicine podcast for physicians. I'm Melanie Cole. And today, we're talking about the role genetic testing plays in cardiovascular care. Joining me is Dr. Elizabeth McNally. She's a cardiologist at Northwestern Medicine and a Elizabeth J. Ward professor and Director of the Center for Genetic Medicine at Northwestern Universe.

Dr McNally, it's a pleasure to have you with us. And this is a really interesting topic and such a burgeoning field that you're in. Tell us a little bit about the role of a genetic counselor and genetic testing in cardiovascular care.

Dr Elizibeth McNally: Well, first of all, thank you for having me today. It's great to be able to talk about this topic. We've seen a real explosion in genetic testing in cardiovascular genetics, especially in the last five to seven years, I would say. I started one of the first cardiovascular genetics clinics in the nation. And so it's been for me very exciting to watch how this has really become mainstream in the care of so many of our patients.

When we do genetic testing, it is quite different than what patients might try to access on their own through some of the commercial sources. And so we're really ordering genetic testing for the most part to try to better define what the diagnosis is in our patients and what the risks are. And so we are very much routinely using that genetic information in the management of patients and probably the place where we find it most helpful is management of arrhythmia risks. And it's for this reason that we've seen genetic testing actually make its way into some of the society guidelines like through the HRS, the Heart Rhythm Society.

I've had the pleasure of working very closely with genetic counselors over most of my career. And they really are so critical to what we do in cardiogenetics. Our counselors play a big role in talking with our patients and providing background information to them as to what to expect when doing genetic testing, what types of results they may get, how this may impact their healthcare, how this may impact their health insurance, disability insurance, and life insurance. And those are questions that come up a lot with our patients who undergo genetic testing.

Just as a quick mention, our patients are protected. They cannot be discriminated against health insurance or their employment on the basis of their genetic findings. But they can be afforded different options with regard to life insurance and disability insurance based on genetic testing. And so that's an important point to raise with patients before they do testing.

Once the results come in, the genetic counselor again, can be very helpful in helping to interpret some of those findings in the context of our individual patients. And then most critically, many of our genetic tests lead to an interaction with the entire family. And that's where again the genetic counselor can be very, very helpful in helping to manage the family members, ensuring their testing and then ultimately their cardiovascular management when those family members end up referred in.

Melanie Cole: What a great point you just made. And since this is about management of already existing cardiovascular disease, when you're working with those families and getting them tested, speak about how you counsel your patients on the role that inherited disease plays with cardiovascular health.

Dr Elizibeth McNally: Well, so I think we're seeing two ways in which it's being used. You're correct in that a lot of our patients already have existing disease, so they may have cardiomyopathy or they may have aortic disease -- that's another place where we do a lot of testing -- or arrhythmia risks. And we'll order what is a gene panel on those patients where we test something from 50 to a 100, 150 different genes that are fully sequenced in those patients. And then we use that information in their management. But we are also seeing some of the genetic testing companies start to offer what are called wellness screening. And that comes from the idea that there is a subset of genes that the American College of Medical Genetics and Genomics have called the medically actionable genes. So that list just recently increased a little over 60 genes and about half of that list is cardiovascular genes. It includes genes for cardiomyopathy, genes for irregular heart rhythms, you know, VT, VF, and then also for the aortopathies, so things that can increase risk for dissections and aneurysms.

And because those are considered medically actionable genes, we are now starting to see some patients undergo these wellness screens and we see referrals on the basis of these wellness screens that they were found to have a genetic change. And now we have to use that information in their management.

The other place where we see it, where these wellness screens or even proactive screens are used a lot is during pregnancy, let's put it this way, or sometimes pre-pregnancy. So we see a fair number of women or sometimes their partners coming in because they underwent some screening because they were planning to have a child or they're pregnant with a child and a genetic test has shown something. So that's quite a different situation. That's a situation where you're dealing with a genetic risk identified by a genotype, and you're trying to assess what the cardiovascular risks are, and then that's separate from those patients that we see much more routinely, I would say, who already have an existing disease and we're doing a genetic test to better refine their risks and manage their care. So we do see both types of testing going on right now.

Melanie Cole: The implications for this testing are astounding, Dr. McNally, for its ability to change the landscape of cardiovascular management. So can you tell us about your process at the Bluhm Cardiovascular Institute at Northwestern Memorial Hospital? How are patients seen in followup by the physician? Or can patients be seen by a cardiologist with testing at the same time? Tell us a little bit about the process.

Dr Elizibeth McNally: So we're pretty flexible in how we do that. Most of our referrals actually do come from other cardiologists. I think many cardiologists aren't entirely sure how to manage this process, although we're seeing some increase in others feeling comfortable with this. But we're happy to see those patients.

Sometimes they're seen first by the genetic counselor who will arrange the testing. Once the testing comes back and the turnaround time for a lot of testing these days is somewhere in the two to four-week range to get those results back. And then they will be seen by one of our cardiologists, usually with the counselor also present, for what we call results disclosure and management. So we will give them their results at that time. Talk about how it's going to affect their care, how we may recommend managing their care based on this information. And then also not forgetting to close the loop about family members who may be at risk, and then those patients return back to their cardiologists often with a set of instructions about how we think this information can be used best in their care.

And again, the most common situation we see this a lot in is people with cardiomyopathies or heart failure, where there's a handful of genes that when we get back result, we know those patients are at much higher risk for arrhythmias, particularly ventricular tachycardia, ventricular fibrillation, so the more concerning arrhythmias that we see.

In that setting, when we see that, it doesn't automatically mean that the patient's going to get a defibrillator. It just may mean that we step up or we recommend stepping up the monitoring for those patients. So loop recorders become particularly helpful in that situation or just increased patch monitoring, we tend to use a lot of that. And of course, for our patients with aortopathy risks, that's mostly some increased imaging that happens in that setting where we're routinely following the aortas and making sure that things are not getting enlarged.

And then in all of these cases, there's usually a shared decision-making process with the patient where we talk about using medications to slow progression of disease. And a lot of this is really oriented towards a little more aggressive blood pressure management.

Melanie Cole: Well, you segued beautifully into my next question here, Dr. McNally, is when you're speaking with your patients and for other providers, when they are counseling their patients, when they get this inevitable questions of what to do with the information, how does this information translate to patient care? Take us from bench to bedside in, for other providers, how you would like them to use this for medical management of cardiovascular disease.

Dr Elizibeth McNally: Again, a lot of what we see is cardiomyopathy. We'll see a patient who has cardiomyopathy, who may have had a family history of cardiomyopathy and heart failure. In that setting, we do very often get a genetic answer. And again, we have a subset of genes that we look at that we know those genes carry a much higher arrhythmia risk associated with it. And generally, our guidelines have told us, for non-ischemic dilated cardiomyopathy, we may not consider a defibrillator until the ejection fraction is less than 35% or less than 30%.

What we know from this handful of genes that we do manage is that in fact their arrhythmia risk can present even when the ejection fraction is 45% or even 50%. And so again, just really speaks to the idea of a much more tailored precision medicine management of these patients, which is to monitor them more closely, instructing the patient as to what symptoms to pay attention to and then treat it when we see those things happening, if we see evidence of VT, nonsustained VT or symptomatic non-sustained VT.

Melanie Cole: Well, it certainly is headed into personalized medicine. Certainly true. Now, as we get ready to wrap up ,what an exciting field you're in, Dr. McNally, and not a very well-known one, but certainly burgeoning. How is the field of cardiovascular genetics and genetic counseling evolving? And what do you see happening in the next 10 years or so?

Dr Elizibeth McNally: Well, I will say it's been a very interesting 18 months for us in the cardiogenetics field, because we do think of these as being more rare disorders. And often we are dealing with patients and families who have sought our help, coming from, to be honest, from many different places, not just the Chicago area, but from many states around or even different parts of the country.

And so one of the small bonuses we've all witnessed in pandemic has been the increase in video visits or tele-health. And so for us, these have actually been quite satisfying for a lot of patients and even their family members who may not be very close to us here, that we can arrange video visits where we review all of their health information, go over their genetic testing results and again, help their local cardiologists manage their individualized care.

So I do wonder whether we will see more of this type of consultative video visit going forward in the future. It works particularly well because we can have the counselor on, we can have the cardiologist on, we can have the patient on, and sometimes we have the patient's family members all joining us at the same time, and they may not be in the same place. And so that can often be most helpful for the patient and their family members to make sure that we're really giving them the best guidance and recommendations for their individual care.

Melanie Cole: Do you have any final thoughts that you'd like to leave other providers with about the Bluhm Cardiovascular Institute at Northwestern Memorial Hospital and how genetic testing is really having an impact on cardiovascular healthcare?

Dr Elizibeth McNally: Well, I think one of the questions we do get asked a lot because many, many people throughout the country have participated in testing, what we call ancestry testing or some of the companies that, again, look at what we call genetic changes throughout the genome, looking for modest risks, those type of gene changes that they detect on those tests are very, very fundamentally different than the ones we do in clinic.

We're deeply sequencing genes and having them done by these external companies and those are actionable results. The kind of testing that somebody might get through ancestry analysis or even some of the other companies like 23andMe is a very different look. I think we will see that start to become a little more mainstream for healthcare management as we see polygenic risk scores come into practice. So that's something to keep an eye on over the next, say, five years. We will probably see more of that coming into practice. And again, patients who've undergone wellness screens and come in with that type of result. That's quite distinct from what we do when we're fully sequencing genes and really using that actionable information in their healthcare

Melanie Cole: What a fascinating episode. Thank you so much, Dr. McNally, for joining us today.

To refer your patient or for more information, please visit our website at breakthroughsforphysicians.nm.org/cardio to get connected with one of our providers. And that concludes this episode of Better Edge, a Northwestern Medicine podcast for physicians. Please remember to subscribe, rate and review this podcast and all the other Northwestern Medicine podcasts. I'm Melanie Cole.