Overview of Hypertrophic Cardiomyopathy

James Januzzi, MD: Hello, and welcome to this HCPLive® Peer Exchange titled “Advances in Treatment of Obstructive Hypertrophic Cardiomyopathy.” I’m James Januzzi. I’m a member of the Massachusetts General Hospital cardiology division and the Hutter Family Professor of Medicine at Harvard Medical School in Boston, Massachusetts. Joining me in this discussion are 4 of my colleagues. Let’s get started. Would you please introduce yourselves? Let’s start with Dr Maron.

Martin S. Maron, MD: Thanks, Jim. I’m Martin Maron. I’m the director for the hypertrophic cardiomyopathy [HCM] center at Tufts Medical Center in Boston, Massachusetts.

Steve R. Ommen, MD: Hi, I’m Steve Ommen. I’m the medical director for the hypertrophic cardiomyopathy clinic at Mayo Clinic in Rochester, Minnesota.

Javed Butler, MD, MPH, MBA: I’m Javed Butler. I’m a heart failure cardiologist at Baylor Scott & White Health system in Dallas, Texas, and I’m a heart failure clinical trialist as well.

John A. Spertus, MD, MPH: I’m John Spertus. I’m a cardiologist at Saint Luke’s Mid America Heart Institute and a professor at the University of Missouri-Kansas City.

James Januzzi, MD: Thanks very much. This is a great panel to discuss an exciting area. Our discussion will focus on hypertrophic cardiomyopathy, or HCM, as you may hear us use that term. We’ll review treatment options available to patients with HCM and share data on novel therapies that are on the near horizon for the treatment of obstructive forms of HCM, or oHCM [obstructive hypertrophic cardiomyopathy]. We’ll also discuss challenges and unmet needs in the treatment of persons with hypertrophic cardiomyopathy. Welcome, everyone. Let’s get started.

Why don’t we start off fairly straightforward. Dr Maron, you work in this area and think a lot about this diagnosis. What is HCM? Let’s start with the incidence and prevalence. How common is this diagnosis?

Martin S. Maron, MD: Hypertrophic cardiomyopathy, or HCM, is 1 of the most common genetic heart diseases in the entire world. It’s probably a prevalence of at least 1 in 500 in the general population and maybe even more common than that with more contemporary diagnostic strategies, even upwards up 1 in 200 around the world. That’s globally, independent of geography, race, and gender. That’s 1 in 200 to 1 in 500. That means that there are probably about 700,000 patients with hypertrophic cardiomyopathy in the United States.

It’s a disease in which there’s an increase in left ventricular wall thickness. That’s an increase in the wall thickness of the left lower chamber. It usually develops early in life. As patients go through life, they’re potentially at risk for a number of different adverse cardiovascular complications.

James Januzzi, MD: That’s really helpful to get us started. We’ll talk about the complications in a second. At what age do people typically start developing signs of hypertrophy if you were able to image them?

Martin S. Maron, MD: Patients are obviously born with the mutation. Disease expression usually starts during puberty for the majority of patients. There’s something about adolescence that turns that mutation on, and patients can develop increased left ventricular wall thickness at that stage. That said, there are certainly exceptions to that in patients who are known to also, although less commonly, develop increased wall thickness after puberty or adolescence, even into midlife. In general, though, that’s when hypertrophy develops, which is different from when patients can develop symptoms. The most common age at which patients come to clinical identification with HCM is much later, usually in their 40s or early 50s.

James Januzzi, MD: Interesting. We’ll talk more about this, but are there disease modifiers? In other words, if someone with a genetic mutation for HCM develops hypertension, does that accelerate the hypertrophy? Or is this independent of outside influence?

Martin S. Maron, MD: That’s a great question. There’s some emerging information to suggest that there may be important modifiers, like comorbidities, hypertension, obesity, or the 2 of them that may impact disease expression. The extent to which that happens and whether we could modify that impact with therapy remains unclear.

James Januzzi, MD: Yes. That’ll tie into the treatment discussion.

Transcript Edited for Clarity