“I met a patient who had a previously implanted heart valve that had reached the end of its useful life and needed reoperation. He had had four previous heart surgeries. So, his face turned gloomy when I told him I would do it again, because he knew how painful it would be. I performed a percutaneous pulmonary valve implantation on him. I still remember his first words after he awoke from anesthesia: Doctor, it doesn't hurt at all...”

Dr. Choi Jae-young, a pediatric cardiologist at Severance Cardiovascular Hospital, one of Korea’s leading authorities on pediatric and congenital heart disease, said so while presenting an example to explain percutaneous pulmonary valve implantation (PPVI) and its benefits to patients.

When a pulmonary artery valve disorder is confirmed due to congenital heart disease, surgery is performed to place an artificial valve or conduit in the right ventricular outflow tract (RVOT). However, over time, the prosthetic valve or conduit can deteriorate and calcify, causing stenosis or regurgitation.

When this happens, reoperation is required to replace the valve or conduit with a new one. The problem is that repeated open-heart surgery is associated with higher risks of operative mortality and morbidity as the number of surgeries increases. In addition, if the replacement time is shortened due to unexpected complications, the number of reoperations increases, burdening patients and medical professionals. PPVI is a treatment that overcomes these problems.

This procedure inserts the pulmonary artery valve without heart-opening surgery, such as pulmonary aortic valve replacement and artificial conduit replacement. It has been widely used worldwide since it was developed 20 years ago. In Korea, Medtronic introduced “Melody” around 2015, which has since been used in clinical practice. Insurance coverage has been applied to it since 2019.

Korea Biomedical Review met with Professor Choi, who has served as the head of the pediatric cardiology department and congenital heart disease hospital and is recognized as an authority at home and abroad and has given more than 100 lectures at international conferences on cardiovascular interventions, to learn congenital pediatric heart disease, PPVI.

Question: What is the treatment process for children born with congenital heart disease?

Answer: First, if the malformation is not severe, we can monitor it and use medication as needed. This is because simple congenital heart defects, such as a hole in the heart at birth, may improve by themselves. Second, there are what we call interventions, including inserting devices through a blood vessel to widen a narrowing, placing a stent, or closing a hole or blood vessel. Finally, there is surgery, which involves opening the chest to repair the deformity and get the heart beating again surgically.

Complex or multifactorial congenital heart disease is a combination of multiple malformations that are difficult to treat with a single surgery. They often require multiple surgeries to correct, and in some cases, corrective surgery is not feasible, requiring life support devices and constant care. Because the artificial materials or valves used in corrective surgery have a lifespan, patients may require repeated surgeries or a combination of surgeries and procedures throughout their lives.

Q: Is there a difference in prevalence between congenital heart conditions?

A: The most common congenital heart conditions are simple heart defects. These include ventricular septal defects, atrial septal defects, patent ductus arteriosus, and pulmonary artery stenosis. A smaller share of congenital heart disease cardiac anomalies is more complex, such as Tetralogy of Fallot (TOF), which accounts for about 8 percent of congenital heart diseases. There is some evidence of prevalence differences between the East and West and among different ethnic groups, with right-side heart anomalies being more common in East Asia and left-side anomalies being more common in the West.

Q: What is the prognosis for patients treated for congenital heart disease?

A: The success rate of procedural or surgical treatment of congenital heart disease has improved dramatically with the advancement of modern medicine. Surgery was considered life-threatening in the past, but the mortality rate is now reported to be less than 0.8 percent, even for open-heart surgery with cardiopulmonary bypass circulation. The actual mortality rate in clinical practice is even lower. Statistically, major complications can occur in as little as 5 percent, but recent results are thought to be lower, and at specialized institutions, we feel the figure is even lower.

Q: Is the treatment prognosis for TOF similar?

A: Yes. Surgical success rates are high, and complication rates are significantly lower than in the past. However, close monitoring of right ventricular outflow tract dysfunction, which occurs in most patients after surgery to correct TOF, is necessary because it is known to irreversibly worsen cardiac function in the long term, leading to a decreased quality of life, premature death, or sudden cardiac death due to arrhythmias. Suppose the right ventricular outflow tract and risk factors, such as right ventricular dysfunction and arrhythmias, are above a certain level. In that case, pulmonary artery valve implantation is necessary to treat right ventricular outflow tract dysfunction. Patients with right ventricular outflow tract dysfunction, including TOF, are considered for pulmonary valve implantation in the long term after corrective surgery in about 23 percent of all congenital heart disease cases.

Q: Despite the procedure's high success rate, we have heard from patients and their families faced with lifelong care that they are anxious about further treatment, including valve replacement.

A: The cumulative risk of mortality or complications increases significantly with the multiple repeats of TAVR (transcatheter aortic valve replaceme3nt) surgeries, and the lifespan of the prosthetic valve is, on average, 10 to 15 years, depending on the valve, which means a lifetime of surgeries. This majorly impacts patients' life plans, including career interruptions. The increased risk of mortality and complications with multiple procedures puts a lot of stress on the patient and their family, which means that the more often a patient needs a new valve, the more they are exposed to risks and the more painful and financially burdensome it is for them and their family.

On the other hand, delaying replacement can lead to sudden death, irreversible right heart failure, and decreased quality of life, so there is a significant dilemma between the two. Against this background, PPVI has been developed and practiced as an alternative to avoid the risks of cardiopulmonary bypass and open-heart surgery, shorten the recovery period after treatment, and reduce the pain and burden on patients and their families. It has been of great help to many patients who have battled heart disease all their lives.

Q: What meaning does PPVI have?

A: PPVI is a treatment that has changed the paradigm of congenital heart disease treatment. As it is a non-surgical procedure, it is relatively simple, and patients can go home as early as two days. Patients only need to check in periodically to ensure they are doing well.

In Korea, the first procedure was performed at Severance Hospital in 2015. At the time of its introduction, it was an expensive procedure, but in 2019, insurance coverage reduced the financial burden on patients, and it has been practiced more actively since then. Before the introduction of PPVI, patients had to undergo repeated prosthetic valve replacement surgery about every 10 years. When I talk to patients about this, they get anxious and ask me how many years they have left to live. However, when I tell them that they no longer have to go through surgery but can do it through a vascular procedure, they become very happy.

If the valve inserted with PPVI fails, a second new valve can be inserted, dramatically reducing the number of open-heart surgeries throughout a lifetime, reducing the pain and risk of repeated surgeries, and improving the patient's quality of life by allowing them to plan their lives without fear of career interruption.

Q: As a physician who has performed numerous transcatheter pulmonary arterialization procedures from 2015 to the present, what is your assessment of their effectiveness and valve durability?

A: To date, there have been no cases where the valve has deteriorated and required reoperation. Because of the nature of the prosthesis, infective endocarditis can occur, and we've had about one in 100 patients who have had to have surgery to treat infective endocarditis. Mid-term results have been available for a very long time, and it has been shown globally that the risks are much more favorable than surgical valve replacement, and the durability is the same. More recently, long-term results up to 12 years have been reported, statistically indistinguishable from surgery. However, real-world reports indicate that the procedure is more durable than surgically implanted valves. PPVI is an important tool that improves the length and quality of life, not only because it replaces surgery but because it reduces the need for patients to live with a debilitating condition that delays surgery.

Q: We're also curious about the latest guidelines for pulmonary valve disease.

A: Guidelines published by the European Society of Cardiology and the American College of Cardiology refer to PPVI as an alternative to surgical valve replacement. Recently, they have recommended that patients with morphologic features suitable for PPVI consider it ahead of other treatments.

Q: Is it being actively practiced in Korea, too?

A: More than 100 cases have already been performed at Severance Hospital. Other major hospitals that treat heart disease are also performing the procedure, but it has yet to be expanded nationwide. To become a PPVI operator, physicians must undergo training provided by the prosthetic valve provider and perform the procedure in the presence of a provider-approved proctor until they gain significant experience. Once they are sufficiently confident in their ability to perform the procedure, they may perform it independently.

Q: Do you have a memorable patient among those you've performed PPVI on?

A: All patients are memorable, but I remember patients who first had negative thoughts about their disease, received the procedure, and changed their thoughts and feelings. I think it's a very important change to see how medicine is advancing and new methods are coming out and to see patients gain confidence, thinking, ‘I can live even with heart disease.’ Some patients are so scared that they hesitate for a long time. Others were physically and mentally traumatized after their previous surgery, vowing not to have it again, even if they died. It's especially memorable when we can make a difference for patients who have been in cardiac distress for a long time.

Q: PPVI has become less burdensome for patients after it got the reimbursement. What else could be improved in its treatment environment?

A: I would like to see easier access to ancillary materials and products that can increase the procedure's success rate. It's not just about having the prosthetic valve but also about getting it safely to where it needs to go and ensuring it's in place and functioning well.

A case in point is the delivery system that comes with the prosthetic valve, a thin tube called a catheter used to place the valve into the pulmonary artery. Many specialized products often play an important role in some cases, including conduits, guideways, and stents. However, since congenital heart disease is rare and the market needs to be larger in Korea, it is difficult to get it. Also, it isn't easy to introduce procedurally because it requires a strict verification process. It also takes a very long time to get sufficient data to be certified academically and commercialized by a national certification agency.

Korea, Japan, and Taiwan are very strict in this regard. The Japanese Food and Drug Administration recognizes U.S. FDA-approved products. However, even if you have FDA/CE approvals in Korea, it takes work. In practical terms, there is a consensus at home and abroad that Korea is the country with the most severe restrictions on the use of materials for congenital heart disease treatment worldwide, resulting in the abandonment of advanced treatment methods due to institutional restrictions on even proven treatments.

Currently, a government agency called the National Institute of Medical Device Safety Information reviews, introduces, and supplies products necessary for treating rare diseases, which has given us some breathing room. However, the reinvigoration of this process and an increase in the budget can help us secure more products that have been difficult to commercialize and be introduced into Korea. It would then be a great help to treat people more safely and effectively. Although there are tools to improve the success and safety of procedures, it's regrettable that we don't have access to them.

On the patient side, I would also like to see support from a life perspective, such as helping people with congenital heart disease who need repeated treatments in the country find jobs.

Q: Finally, what words will you give to patients and caregivers of people with congenital heart disease?

A: Take an interest in your condition. The most typical patients for this procedure are those with TOF, the most common complex congenital heart disease. It accounts for about one in 10 congenital heart diseases. Patients receive surgery when they're young and think they don't have any more heart problems but come back later with many problems. In younger patients, caregivers need to be aware of what to look out for and how to manage them until they reach adulthood. Delayed treatment can lead to irreversible conditions, so it's important to work closely with your healthcare provider as soon as you notice any abnormalities.