Structural Heart Disease: A Q&A With Cardiologist Stephen Kidd
Dr. Stephen Kidd, cardiologist with the CentraCare Heart and Vascular Center, spoke with WJON’s Jay Caldwell about structural heart disease and its treatments. The interview below was edited for length and clarity.
Q: What is structural heart disease?
Dr. Stephen Kidd: Your heart is like an engine, and it has four chambers, two to collect blood and two to pump blood. As it's going between each of those chambers, there are four valves to allow the blood to continuously circulate in one direction. I would describe structural heart disease as heart conditions that primarily involve the heart valves. Structural heart disease also addresses issues such as fixing a hole in the heart, plugging a spot in the heart where clots form, or more rarely, removing tumors or other abnormalities from the heart. Structural heart disease does not directly involve the coronary arteries or electrical system of the heart.
Q: Are there symptoms of structural heart disease a person can notice?
Dr. Stephen Kidd: The most common symptoms are shortness of breath, chest pain and decreased exercise tolerance. Some people might be more prone to becoming lightheaded with movement or even faint.
Q: Does structural heart disease affect all ages?
Dr. Stephen Kidd: We take care of patients who were born with heart conditions related to a patent foramen ovale or atrial septal defect. Those are generally in younger populations. In the intermediate population, we do a lot of what's called a WATCHMAN procedure. People who have this procedure have an arrhythmia called atrial fibrillation or AFib, which is an irregular heartbeat. They are often put on blood thinners to prevent stroke. With the WATCHMAN procedure, we plug the part of the heart where blood clots form to reduce that risk of stroke and dependence on blood thinners. Lastly, valve problems are generally more common as we age, more so after age 70. The oldest patient I’ve done a valve replacement on was 104 years old and she left the next day, walking around that evening.
Q: Should people be concerned about their heart valves?
Dr. Stephen Kidd: People are often asymptomatic during the early phases of a valve issue. And even after the valve has become severe enough to replace, people may not realize they have symptoms. This is not like a heart attack where you're fine one minute, and the next minute you're clenching your chest.
In general, the typical patient with severe aortic stenosis, which is the most common valve problem that we experience as we age, will come in with a family member and the patient may say, “I feel fine.” I always ask the family member, “Do you agree?” Very frequently the family member says, “Dad, you can't even make it to the mailbox anymore,” and he says, “Sure I can, I'm just getting old.” And I say, “That's true, but if you have a bad heart valve or have other issues, it’s like having a restrictor plate; you're only using two out of your six cylinders.” Everybody slows down when older. But if you notice it over the course of a year, it’s probably something else. Most of the time when we fix a valve problem the patient says, “Wow, I didn't know I could feel this young.”
But I want to reassure everybody that this is not something you have to call your doctor and get an emergency appointment for. But this is why good primary care doctors still listen to the heart. And if they hear a murmur, they do an ultrasound and if it shows a serious problem, they come to us.
Q: If you're going to fix a valve problem, could that also fix some problems related to blocked arteries?
Dr. Stephen Kidd: CentraCare is enrolling in a clinical trial that's trying to determine, with a high level of precision, the answer to that question. It’s like looking under the hood of a classic car and taking apart the engine. When doing so, you find things that are wrong that have otherwise been working well for 200,000 miles. It's common that as we're planning on fixing the valve, we find some blockages of the arteries or coronary artery disease. What we don't know right now is, do you fix that at the time of the valve replacement, before, after or do you leave it alone? Sometimes if you replace the valve, the symptoms go away completely and that blockage that may have seemed bad before now isn't quite as bad. The blockage is there, but when the heart is able to work more efficiently, that blockage may no longer cause any problems. These problems are both a product of aging and certainly share an underlying cause but fixing one doesn't inherently fix the other. Oftentimes people will feel better by only fixing the valve.
Q: When you do a valve replacement, what are those new valves made of?
Dr. Stephen Kidd: The valves themselves are normally made from either cow or pig tissue. However, they are not the actual valve from the animal. Rather it is the lining around that animal's heart, which is called the pericardium. This lining is then harvested, treated in a preservative, cut and sewn into what looks like a cage. That cage is crimped or compressed and then put into a delivery device of some kind, effectively a hollow tube, and then through that hollow tube, I deploy the device to the heart.
Your old heart valve will always stay in place, but we will put the new heart valve inside of it. People ask me, “How long is this going to last?” I tell them, “The great thing is, I don't know because they just keep lasting.” Approximately 10 to 15 years ago, this wasn't really a thing. When considering the lifespan of a valve, I consider a person’s lifetime. With anything mechanical, your tires or transmission, you only get so many miles on it. Since a new valve will wear out at some point, we carefully choose this valve. We have multiple choices of valves. If the first new valve fails, I’ve already planned out the next valve that would work within this valve. So, I'm always thinking, depending on the age of the patient, what will be my second or even third valve? I always assume someone is going to live to be at least 90 years old and plan accordingly.
Q: Have these procedures changed over time?
Dr. Stephen Kidd: These procedures didn't exist 15 years ago, and they have created a revolution in how we care for our patients. For example, aortic stenosis is a very tight heart valve that puts people at risk of fainting, heart failure and congestive heart failure. People with severe aortic stenosis as soon as 10 years ago would effectively be told there's nothing that they could do and to seek palliative care. Now, CentraCare alone does about 250 aortic valve replacements and about 50 mitral valve replacements a year, and this is something that has revolutionized our ability to treat our patients.
Q: Are people living longer because of this?
Dr. Stephen Kidd: Absolutely. I always tell my patients, in medicine, we are tasked with making sure that all of our treatments do at least one, hopefully two things. They have to either make people live longer or feel better. If you can do both, it's a home run. Without a doubt, the expansion of structural heart disease treatment has allowed people to live longer, healthier and happier lives.
Q: If someone is diagnosed with structural heart disease, what do you tell a patient at this point?
Dr. Stephen Kidd: I say it's the best time to have this diagnosis in the history of man. This field did not exist 15 years ago, and in the last decade, we have seen an explosion in the number of devices, our experiences with these devices and the ability to treat complicated patients with very good outcomes.
America dominates the biotech industry, and there's a couple reasons for that. One is Americans are inherently hardworking, smart people and we like making stuff and being rewarded for it. Number two is, Americans trust their doctors and in general enroll in clinical trials at a rate higher than other countries. This has been part of the reason why we have been so successful in dominating the planet in the development of these products.
St. Cloud Hospital has a very robust cardiovascular research program, and we are top enrollers in many clinical trials, giving patients access to very advanced technology. As part of this research, if before you couldn’t get a surgical valve replacement due to your anatomy, now we can deliver a valve to your heart through the groin, carotid artery or the shoulder — and have excellent results. It takes us about 30 minutes and people are walking around later that day and go home soon after.
I'm blessed to be practicing cardiology at this transformative time. With these new technologies, we're often able to deliver on our promise to increase your quality and quantity of life because the recovery time is measured in hours, not days, weeks or months. If you were told you didn't have an option before and you know you have valve problems, come see us in St. Cloud.
Read Structural Heart Disease, AFib & Heart Failure: A Q&A With Cardiologist Stephen Kidd.