Intro: It's Your Health Radio, a special podcast series presented by Henry Mayo New Hall Hospital. Here's Melanie Cole.

Melanie Cole, MS (Host): Ninety percent of blood flow to the heart comes through tiny vessels, not through larger coronary arteries. Detecting blockages in these small blood vessels can be difficult. Henry Mayo Newhall Hospital is deploying a new technology, CoroFlow, that's specifically designed to detect these blockages in small vessels.

Welcome to It's Your Health Radio with Henry Mayo Newhall Hospital. I'm Melanie Cole. And joining me today is Jennifer Whitcomb. She's a registered nurse and the Director of Cardiovascular Services at Henry Mayo Newhall Hospital. Jennifer, thank you so much for joining us today. This is a really great topic. But before we get into this new tool for detecting heart disease earlier, what is microvascular circulation? Tell us a little bit about why that's so important. And while you're telling us this, how coronary microvascular disease and traditional coronary artery disease, how they differ.

Jennifer Whitcomb: Sure, Melanie. So when we speak about coronary disease, we typically are speaking of three main what we call epicardial coronary arteries. We have the left anterior descending, we have the circumflex artery, and then we have the right coronary artery. So when we talk about coronary disease, these are the three vessels we're talking about. But the main circulation of the heart, actually, like you said, comes from the microcirculation, which are the smaller vessels, like the capillaries and their arterioles. And they do account for 90% of the circulation of the heart. So, the main coronary arteries that we speak so much about only really encompass about 10% of the circulation of the heart. So when a patient comes in with what we call obstructive coronary disease, the typical treatment is angioplasty and stenting, but it doesn't always resolve the patient's angina. So, 20-40% of the time, they come back with reoccurring chest pain and we don't see any further obstruction in their epicardial coronary arteries.

So usually, it's present in the microvasculature. We're just kind of learning about this now. This is a relatively new technology. It's assisting us in detecting disease that previously we couldn't detect, and this was creating a burden on hospitals and patients and causing disability, readmissions. We would come in and we couldn't find any disease, so we would send them home and say, "You know, it's not coronary, it's not cardiac-related." But now with this technology, we can easily diagnose this microvascular disease and then we can medically manage it and treat it.

Melanie Cole, MS: This is really exciting. And to me as an exercise physiologist and having worked in a catH lab, we did, we had to send people home and say, "I'm sorry." You know, and certainly, women, we get chest pains all the time for all kinds of reasons, and stress and panic attacks and everything else. So, it's really great that there is this new technology. And why don't you tell us about it? The CoroFlow pressure wire, what does it do and how does it differ from what we've had?

Jennifer Whitcomb: We currently have what we call a pressure wire, that we use in the main coronary arteries. And what this wire does is we put it across the blockage and it measures the resistance before and after the blockage. So, it gives us a number, an index, that tells us how significant that blockage is and whether we need to intervene and stent it. That's how it works in the coronary arteries. With this wire, it's the same technology, but it goes down the microvascular vessels and tells us if there's any obstructive disease in the microvasculature. Now, because it's so small, we can't treat it with angioplasty and stenting, but we can medically manage it now with medications and anti-anginal medications like long-acting nitroglycerin, beta-blockers. There's many medications that can be used to medically manage these patients, and give them a better quality of life and reduce their amount of visits to the doctor in the hospital.

Melanie Cole, MS: Have you seen it work, Jennifer? Is it basically the same as a regular cath? Have you watched it go through those tiny arteries?

Jennifer Whitcomb: I have seen videos of it. We don't have it yet at Henry Mayo where it's in the process of going through all of our committees for approval, but it's the same exact technology as what we currently use. Fractional flow resistance is what we use in the coronary arteries. And this is IMR instead of FFR, and it's called index of microvascular resistance. So, it's essentially the same technology, just in the microvasculature.

Melanie Cole, MS: Isn't that so cool, that they're coming up with these things and what an exciting time in your field. And you and I mentioned this a little bit before and then I touched on it, and I understand that this will be especially beneficial to women. Can you explain why that is?

Jennifer Whitcomb: You know, about 60% of these patients that present with ischemia due to non-obstructive coronary arteries, or what we call INoCA, 60% of these patients are women. So, women, they frequently come in with symptoms and chest pain and we do a cath on them, a cardiac cath on them, and they don't have any obstructive disease. So, we do, we send them home and we label them with anxiety or asthma or, you know, "Go see your pulmonary doctor", "Go see your GI doctor." And it's really congesting the healthcare system, and it's not helping their quality of life. So, it's really important for women especially, because this is going to be present in a lot of women who are presenting with chest pain.

Melanie Cole, MS: Tell us a little bit about treatment options. And you mentioned a few medications earlier, but if you do detect coronary microvascular disease, can you start with some lifestyle modifications? Does it make someone eligible for cardiac rehab? Tell us a little bit about the process afterwards.

Jennifer Whitcomb: The process afterwards, it's a combination of everything we do for the main coronary arteries, but without the intervention of stenting, lifestyle changes, obviously, now we know this person has coronary disease, so it's crucial that they get on the right medications, the lipid medications, the cardiac medications, aspirin. But then, it's also crucial they change their lifestyle, just as if they had a stent placed. So, they need to get active and be on a low-fat diet, a heart-healthy diet. There's a lot of things. You know, we haven't investigated cardiac rehab yet because we haven't adopted this wire yet, but there is a good chance that this population could benefit from that.

Melanie Cole, MS: This is really important information. So, why don't you wrap it up and tell us what you would like listeners to know about CoroFlow pressure wire, what's coming to Henry Mayo New Hall Hospital and coronary microvascular disease? If you'd like to mention symptoms or things that people should just really be aware of, I think that's important.

Jennifer Whitcomb: Sure. It's really important when you have symptoms of any kind, whether it's chest pain, back pain. We get all kinds of walks of life. We get tooth pain, jaw pain, GI upset, all of those things between the chin and the stomach is what we say, it could possibly be cardiac. So, it is important to always get worked up and come to the emergency room if you're having chest pain, especially with women because we, as women, tend to kind of ignore symptoms, we push forward, and it is really important. There's a lot of different kinds of disease that women can present with that's not a typical, blockage in the major coronary artery, but it is crucial that they get it looked at and medically managed.

Melanie Cole, MS: Thank you so much, Jennifer, for joining us today and telling us about this exciting technology coming to Henry Mayo New Hall Hospital. And to learn more about heart care at Henry Mayo New Hall Hospital, please visit henrymayo.com/heart. You can also visit the free health information library at library.henrymayo.Com at any time for information that you can really trust. That concludes this episode of It's Your Health Radio with Henry Mayo New Hall Hospital. I'm Melanie Cole. And please always remember to subscribe, rate, and review this podcast and all the other Henry Mayo New Hall Hospital podcasts. Thanks so much for joining us today.