Radiation Heart Disease

Podcast Transcript

Announcer:

Welcome to Cleveland Clinic Cardiac Consult, brought to you by the Sydell and Arnold Miller Family Heart, Vascular and Thoracic Institute at Cleveland Clinic.

Milind Desai, MD, MBA:

Hello, everybody. My name is Milind Desai and I am a cardiologist and Vice Chair of Heart, Vascular and Thoracic Institute at the Cleveland Clinic in Cleveland, Ohio. It is my pleasure to invite everybody to join in this wonderful podcast where I will be joined also by my colleague and good friend Dr. Shinya Unai.

Shinya Unai, MD:

Hi, my name Shinya Unai. I'm one of the staff surgeons at the Cleveland Clinic.

Milind Desai, MD, MBA:

Today we are going to talk about a very interesting topic, radiation-associated cardiovascular disease.

Shinya Unai, MD:

So Dr. Desai, when we get a referral for patients that had radiation, how would you approach these patients?

Milind Desai, MD, MBA:

These are some of the most challenging patients we see in pretty much all of cardiovascular medicine. These patients, first and foremost, we have to think about these patients given their past medical history. So if you had metal radiation or massive radiation to the chest years ago, all these patients could potentially have radiation-associated cardiovascular disease features. The biggest problem is often underrecognition, misdiagnosis, and incomplete workup where people do not connect all the dots. So that's why it is important to have a broad look at these patients, certainly at an experienced center.

So when a patient is referred to us with the suspected history of radiation heart disease, we look at every patient on his or her individual merit. We do extensive not only clinical evaluation, but multimodality evaluation. So obviously a thorough history and physical of what the radiation was, where the radiation was, check out the tattoos related to the radiation, try and get the amount of radiation they got. Are there any additional risk factors that could aggravate radiation heart disease?

We do multimodality imaging, so a thorough echo, which often reveals peculiar features that we've learned over the years that are associated with radiation heart disease, including multiple valves that could be affected. You could have thickening of the area between the aortic and mitral valve, aortic mitral curtain. You could have a heart dysfunction or a stiff heart. Pretty much everybody should and does get a CAT scan to look at the lungs for traction bronchiectasis or fibrosis radiation damage. We also look at calcification known as porcelain aorta or massive calcification of the aorta because that is often seen. Then we also look at basically coronary anatomy because these patients often also have very aggressive, very proximal coronary artery disease. Each and every patient, we at least as baseline look at their lung function studies, including diffusion capacity, which looks whether or not the lungs are restricted.

Depending upon where the radiation could have extended, we may also need to look at the carotid arteries. Why is this important? Because radiation heart disease is what I would classically call pancarditis. So if you've got radiated in your chest, anything and everything that comes in the way of the radiation beam is fair game for potential damage. The damage is mostly due to fibrosis or scar tissue. So skin, bones, lung lining, lungs, aorta, pericardium, coronary artery disease, valves, electrical system, carotid, thyroid gland, esophagus, anything and everything. So we have to think and plan for all those things.

Beyond the basic imaging, we would then, in a lot of cases, we would also look at cardiac MRI to look for features of restriction or constrictive pericarditis. My threshold for doing a right and a left heart catheterization is very, very low in these patients. I typically do not rely on stress testing because of a high rate of ostial proximal disease and a high rate of false negatives. You will see me order left heart catheterization and a right heart catheterization with invasive hemodynamics very often in these patients.

In general, once we clinically evaluate, once we do these multimodality imaging evaluations, I see the patients back typically the same day, the next day, and synthesize the data and basically figure out what the next steps are. In very often many, many cases is this person, this patient needs advanced therapeutic interventions, which is when I often call you, Dr. Unai. Once I have worked these patients up, I figured out they have advanced radiation heart disease, and they're symptomatic because of that, I refer them off to you. What goes through your mind as you are referred a patient with radiation heart disease?

Shinya Unai, MD:

Patients that come to us for surgery can have a wide variety of cardiac issues, coronary disease that requires bypass surgery, valve disease, typically the aortic valve and the mitral valve. They're fibrotic and calcified and they can be leaky or stenotic, but typically they cannot be repaired and may need a replacement. These valves can be heavily calcified. Not only a valve, but the surrounding tissue can be calcified as well and may require extensive decalcification. The tissue in between the aortic valve and the mitral valve can be calcified as well. Reconstructing that tissue, commonly referred to as the Commando procedure, may be required to place an adequately sized valve.

The aorta can be also be heavily calcified, referred to as a porous aorta. This may need a replacement also. To replace this aorta, we may need to cool down the body temperature, protect the vital organs and the brain, and stop the circulation for a while to replace the aorta, similar to what we do for aortic dissection surgery.

The sac surrounding the heart, called the pericardium, can also be fibrotic and calcified from radiation and lead to restriction. In these cases, rather than the traditionally performed pericardiectomy, which only removes part of the pericardium, the anterior part of the pericardium, we perform what we call a radical pericardiectomy that removes the entire pericardium, including not only the anterior part of the pericardium, but the inferior and posterior pericardium. We completely remove the sacs surrounding the heart to remove the constriction completely.

Most patients with a history of radiation will have some degree of fibrosis and restriction of the heart muscle as well, which can lead to slow recovery from the bypass machine. They may spend some time in the intensive care unit. In some situations, these patients may require mechanical support, either with an internal balloon pump or with an Impella; a pump that goes into the heart directly to assist may be required.

To further complicate the situation, radiation can affect the nearby lungs and may have some degree of impaired function as well. For very few patients that have severe restriction and dysfunction of the heart, transplantation may be the only option, either just a heart or a heart-lung transplantation.

A successful outcome for these complex radiation heart disease patients requires an experienced anesthesiologist, a cardiac surgical team, and an intensive care unit that is comfortable managing all these complex issues.

Milind Desai, MD, MBA:

So let me ask you a question. Say the patient presents to us and we decide heart surgery is a complicated affair in these patients. Say the patient only has one valve that is diseased or just one or two coronary arteries that are diseased. How do we approach this as a team?

Shinya Unai, MD:

Since these patients are at increased risk with heart surgery, we typically try to avoid heart surgery as much as possible. So when we see these patients as a group with an experienced cardiologist that is experienced in radiation, a cardiac surgeon and an interventional cardiologist, and look at the anatomy and figure out what can be treated with a catheter and what cannot be treated with a catheter and may require an open heart surgery.

Milind Desai, MD, MBA:

I think what Dr. Unai is suggesting is we have to learn from our past experiences. At the Cleveland Clinic, we've learned a lot about this disease from our past experiences. In our prior publications, we have shown that open heart surgery in these patients is riskier than in the average patient, but in carefully selected patients, the outcomes are very, very good.

One of the words of caution that we've learned over the years is we know that re-operation in this group tends to be a much higher risk proposition. So at least as a team, what we are trying to do is avoid a re-operation. In the case of radiation heart disease, our goal is to fix everything that needs to be fixed in one setting and avoid multiple re-operations. We definitely try to minimize the urge to go and fix a single valve or just a one-vessel CABG, one-vessel bypass, et cetera. We wait for the disease to progress. So in waiting for the disease to progress, if we have to do a catheter-based intervention in the interim, that's what we often end up doing.

Again, the data on outcomes is radiation heart disease patients have to be treated with extra care because in patients that are not well managed, the outcomes can be bad. That's where experience, a team discussion, everything comes into play.

In the post-op setting, Dr. Unai, what other things do we watch out for in terms of recovery? How do you manage patients' and families' expectations?

Shinya Unai, MD:

When I see patients with radiation, when I talk about heart surgery, the risk of the operation, it is not uncommon to see these patients that, if not for radiation, would be out of the ICU intensive care unit in two, three days. However, with the restriction in fibrosis of the heart, it may take a little while for the heart to recover completely. It's not uncommon that the patients will require inotropic support for a few days, even if the systolic function, the squeezing of the heart is normal.

In addition, because the radiation may affect the lung function as well, the separation from the ventilator may take a little more time than usual. In addition, because of the lymphatic dysfunction from the radiation, it is not uncommon that these patients develop fluid around the lung requiring thoracentesis or a small catheter in the pleural space to remove the fluids. So in general, I typically say at least a few days up to a week in the ICU and the hospital stay can be up to two, three weeks even in best case scenario.

Milind Desai, MD, MBA:

I think this is important to recognize because often, yes, you are absolutely right. As I am working patients up early on, I am doing a lot of stuff managing families’ expectations because a lot of these patients come from out of town, often from many states away, so their stay in the hospital and in the surrounding area after their discharge is a little prolonged. Often it is important to recognize every fluid buildup in and around the lungs in the post-op setting is not due to heart failure. A lot of it is due to lymph drainage and just pounding patients with diuretics may or may not be the best strategy. I think some of these things are absolutely important to recognize and to manage expectations.

An important comment actually I wanted to make is in our experience, transplantation is one potential option, but what we've seen over the years is a lot of times we reserve that as the absolute, absolute last option because a lot of these patients, they've had prior malignancies and with transplant, what ends up happening is you immunosuppress them. You give them immunosuppressants and some other cancer emerges. So we try our best to take care of these patients through standard surgical things. But it is also important to recognize that this disease can be predictable, so you need to start screening these patients at an appropriate time so that you don't get to an advanced stage or you plan for a procedure well before they get to an advanced stage. I think that is important.

The other important thing, at least I hope that by the time my career winds down, this disease will no longer exist because there's a lot of new technology that is evolving in radiation oncology where they use better sources of radiation, they radiate less, and they protect the heart and the vital organs in a much better fashion than what was happening 20, 25 years ago. I think the best option in these patients would be, as they say, prevention is better than cure.

Any last words, Dr. Unai?

Shinya Unai, MD:

I think the most important message is that for patients with radiation heart disease, we have to have a plan for the next 20 to 30 years. Again, we try to emphasize the importance that we don't want to do multiple heart surgeries, we want to plan for one heart surgery at the right time. Before that, we try to discuss as a group, as a team, how to avoid a second heart surgery. How can we delay the first heart surgery with percutaneous options? I think the team discussion is very important. At the Cleveland Clinic, I think we have a great team of interventional cardiologists, cardiologists, cardiac surgeons and intensive care to manage these patients that could be highly complex.

Milind Desai, MD, MBA:

This disease truly represents a team effort. A presence of an highly experienced team at a highly experienced center is absolutely important in excellent outcomes. It's the surgeon, the imager, the clinical cardiologist, the interventional cardiologist. But not only that, the ICU support staff, the anesthesiologist, the post-op nursing floor, everybody works in sync to take care of these patients so that we are not reinventing the wheel every time a patient like this is seen. Thank you again for joining. Hope you found this useful.

Shinya Unai, MD:

Thank you.

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