Expert Guidance on Novel Treatment Approaches in Obstructive Hypertrophic Cardiomyopathy - Episode 8

Septal Reduction Therapies in oHCM

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Expert cardiologists share approaches to the challenges that come with septal reduction therapy, as well as access to oHCM treatment.

Anjali Owens, MD: Andrew, take us back to the patient who maybe hasn't had a good response to the beta blocker or calcium channel blocker, even a combination of those 2 agents. How do you approach talking to a patient and selecting the right septal reduction therapy [SRT], and what are the challenges that come with those invasive therapies?

Andrew Wang, MD: So when I talked to a patient about the pharmacologic therapy, I say none of the drugs that we know of significantly reduced the degree of hypertrophy. If we're talking about something definitive to address the hypertrophy, that's when we start talking about septal reduction therapies. The 2 most commonly used ones now that have a good track record and experience would be either surgical myectomy, which has been available for more than 60 years, or alcohol septal ablation, which has been around for more like 25 to 30 years, I tell patients. That the decision oftentimes is up to them between what they think would fit best with their lifestyle. But we may recommend 1 or the other based on either their comorbidities and their ability to get through a cardiac surgery, perhaps favoring, then a less invasive alcohol septal ablation procedure or their anatomy. There are some anatomies where it is not just the sigmoid basal septal hypertrophy that could be addressed within alcohol septal ablation, but more complex hypertrophic cardiomyopathy [HCM] anatomies, particularly those that have concomitant mitral valve disease, which can happen in 1 in 5 patients with hypertrophic cardiomyopathy, where a surgical approach would address multiple different components of that outflow tract obstruction. So I think we try to give a best recommendation, but oftentimes there is equipoise about what would be the most effective in terms of alleviating their symptoms and patients will ask the right questions most of the time and decide, OK, this one I think is fits with my current plan for my health.

Anjali Owens, MD: Great, and Milind I’ll just end this segment with talking a little bit about access to septal reduction therapy and high-volume centers. I know you recently published some work on this. What's your opinion on where myectomy is are done and where they should be done?

Milind Desai, MD, MBA: So this is an important question to answer because of substantial heterogeneity in outcomes based on a given centers experience. The paper that you alluded to looked at SRT landscape in the USA and what we found amongst are there are also multiple other publications that have shown that if you go to a highly experienced center for an SRT procedure,your mortality rate is like in the 0.5% range, often many years it is 0%. But if you go to a low-volume center, that's just doing occasional procedures like this, the mortality can reach all the way up to 16%. That's a big number and that's just mortality. In hospital or in post procedure mortality, VSD [ventricular septal defect], uncorrected problems, persistent gradients, all those things aside, 16% mortality. So it is important SRT works. When it works, it is a really gratifying result in an operation, but you have to find the right center. The unfortunate reality of the landscape in USA that was, I think, the punchline of the paper is in spite of the inverse association between outcomes and surgical volumes or procedure volume. Seventy percent of US patients with obstructive HCM went to lower-volume centers. So clearly there's an unmet need to consider broadening the tent of available options.

Andrew Wang, MD: To add to that, the number of cases of either form of SRT that would be in the higher tertile of volume is still surprisingly low. So when we talk about when we talk about high-volume centers, I think if you said that to a patient they would say, "Oh you're doing 50, 100 a year,” we're talking about in the highest tertile that you're in the teens perhaps. So there are a very high number of low volume centers and I used to feel a little bit uncomfortable when patients ask me how many of these have been done here this year How many of these have been done? But now I think it really should be almost publicly reported information. Because really across all of cardiology, there's such a strong relationship between volume and outcome. So I think the patient is actually doing their homework when they ask that question.

Milind Desai, MD, MBA: It's a different connotation when you're looking at the patient straight in the eye and saying, “Yeah, our center does about 40 or 50 of these a year”, versus this is a surgeon who’s done 2500 of you know, so there are connotations to this, and that should be addressed. And like Andrew said, it should, I think it is the narrative will shift now with available newer therapies to sort of you know publicly report these types of things.

Anjali Owens, MD: It’s us to have really open conversations with their patients as they're weighing these very, you know, heavy and sometimes life-changing decisions. So Michelle, are there other current unmet needs in obstructive HCM?

Michelle M. Kittleson, MD, PhD: How much time do we have?

Anjali Owens, MD: I'll give you about 2 minutes to answer that.

Michelle M. Kittleson, MD, PhD: So I think there's so many things we still need to know preventive disease, modifying therapies, clinical trials that focus on patient reported outcomes with information on the differential impact of therapies based on sex, race, ethnicity, and not specifically for obstructive HCM, but for all HCM patients. Accurate sudden cardiac death risk assessment, wider access to genetic counseling, which is an essential component of genetic testing and guidance on things like exercise sports participation. I think this is what makes the field exciting for us. There's so much we have still left to learn.

Anjali Owens, MD: That was wonderful. You gave us about 20 things to do for the next decade.

Transcript is AI-generated and edited for clarity and readability.