Thoracic surgeons had long conducted surgeries to treat heart diseases. In the early 2000s, the advent of drug-eluting stents coated with drugs that prevent blood clots dramatically improved the treatment’s efficiency and patients’ convenience.

Stenting is one of the interventional procedures most used for patients with cardiac infarction or angina. Interventional procedures are a non-surgical treatment used to open narrowed coronary arteries to improve blood flow to the heart and are not considered surgical procedures because they do not require a large incision used to open the chest.

Professor Lee Byoung-kwon of the Department of Cardiology at Gangnam Severance Hospital has established the interventional cardiac procedure as one of the first-generation cardiologists in Korea.

Korea Biomedical Review met with Professor Lee to learn more about stent procedures and the room for improvement in the future.

Lee also served as a research fellow at the Department of Physiology and Biophysics of Keck School of Medicine of University of Southern California (USC) between 2005 and 2007 and as a professional exchange scholar at the Department of Hematology at USC 2016 and 2017.

“I chose to specialize in cardiology as I could see the recovery and predict the prognosis of patients when diagnosed and treated on time, even if that means cardiologists have to face many emergency patients,” Professor Lee said.

Lee explained that the diagnosis, result, and analysis of the outcomes are come out in numerical values, describing cardiology as math. 

“Our heart is like mathematics, and if you know the principle and find out which part of it can be treated, you will get a direct outcome. This is different from other diseases like cancer and hepatitis that have to wait for the drugs to take effect and confirm the efficacy,” Professor Lee said.

Three risk factors and causes of heart diseases

According to Lee, there are three risk factors in most cardiac diseases. Age and genetic background lead to heart attack or angina. Unfortunately, the two factors cannot be intervened or controlled externally.

The daily lifestyle, including alcohol, tobacco, diet, and exercise, also significantly impacts developing heart diseases.

“The third factor results in hypertension, diabetes, and hyperlipidemia, of which diabetes is the worst,” Lee said. “This is because diabetes destroys blood vessels, large and peripheral. Suppose patients had diabetes for a long time. In that case, they must keep in mind that they are likely to have arteriosclerosis in the not-so-distant future.”

The cardiologist compared the heart as a “car engine,” having a pump, valves, fuel supplier, and networks. If there is a problem with the fuel supply system, the engine will not run, and the heart will suffer. The problem in blood vessels usually leads to ischemic myocardial disease, myocardial infarction, angina pectoris. When the cardiac muscle and heart valve fails, the engine will fail to carry out its job, eventually leading to heart failure.

Problems in the network of the cardiovascular system will result in unsuccessful regulation of beat and failure to control the heartbeat adjusted to the required condition, usually called arrhythmia, Lee said.

Golden time for stent implant in angina, heart attack

Once patients’ blood vessel is completely blocked, they form blood clots and require stent implantation.

Doctors use a stent to open blocked arteries for patients with angina, where the blood vessel is narrowed by more than 70 percent. If the heart cannot pump enough blood when it needs more beats, patients will feel worse.

Also, patients need to be treated “within three hours” of the onset of symptoms for myocardial infarction. The heart muscle and blood vessels will die out after the “golden time.” The faster you open the arteries, the more heart cells patients will preserve. After the third hour, about 70 to 80 percent of the heart muscle is likely to die due to the blockage.

“When an emergency patient with myocardial infarction arrives in our hospital, we have to be ready to be there by 20 minutes no matter where you were at the moment,” Lee said. “Doctors on call have to prepare to begin the surgery between 30 minutes to a maximum of an hour and arrive at the hospital in 20 minutes as well.”

Lee said before the Covid-19 pandemic had quite a few foreign patients visiting for treatment. Many came from Kazakhstan, Russia, Indonesia, Vietnam, and China.

Lee pointed out that several overseas patients who visit the hospital have relatively poor management over their lifestyle and risk factors, with lower access to medical care.

In Korea, a stent placement cost usually ranges between 7-8 million won ($5,900-6,800), but Koreans have only to pay 1-2 million won after receiving healthcare insurance.

There are cases of sudden death as the heart suddenly trembles, leading to a severe arrhythmia when the blocked blood vessels are not opened quickly enough.

“In this case, we use electroconvulsive therapy and cardiopulmonary resuscitation, but the heart often returns to normal after proper treatment and puncture of blood vessels,” Lee said. “In serious cases, we had to perform CPR and treat the blocked vessels with the stent procedure at the same time, just like you have seen in the movies.”

Sometimes blood vessels burst while the surgeons try to open the artery, which leaves them no other option but to close the rupture and find another pathway to treat the initially blocked vessel.

Lee explained that surgeons must solve the problem in five minutes in emergency cases as the patients’ brains will start to die due to lack of blood flow.

Rooms for improvement in stent procedure and the global trend

Asked about parts that could be improved in domestic stent procedures, Lee pointed out the lack of homegrown technologies and medical devices used in the operations.

“Most medical instruments and tools, diagnostic equipment, and facilities are all developed by countries with advanced medical care, including the stent procedure,” Lee said. “We need more homemade medical devices meeting the global level, and support for the labor-intensive tasks we carry out, or the nation will continue to see fewer people specializing in related medical fields like we are devoted to.”

Lee said medical students tend to avoid specializing in the departments of surgery, obstetrics and gynecology, thoracic surgery, and cardiology, reducing specialists in these areas to dangerously low levels.

He stressed that the government should cover more reimbursement for demanding operations and provide further support for domestic medical device developers to match global companies.

At a global level, domestic and overseas stent makers are continuing to develop better products.

“Beginning from the first generation of metal mesh stent, we have applied a technology that prevents it from narrowing again by coating it with drugs, developed a more hydrodynamic design, and made thinner, longer, and stronger with alloy material,” Lee said. “However, if the arteries are completely hardened like a stone, it cannot be resolved with a stent, and surgeons will have to open the chest for surgery.”

According to Lee, some 5 to 10 percent of all emergency patients with heart disease will have to open their chest for coronary artery bypass surgery, while the remaining 90 to 95 percent can be treated with stenting.

Heart components age with you and require proper management

“Our team has been performing about 500 to 600 diagnostic angiography a year, of which 30 percent of the patients have to receive stent placement,” Lee said. “We have treated about 200 cases on average with stenting annually, so I believe we have done about 4,000 procedures in the past 20 years.”

Lee said that early diagnosis could help patients recover from heart diseases well, and they might be able to live up to their expected lifespan by managing risk factors and daily lifestyles. According to Lee, stenting is one of the last steps patients can seek for their heart diseases.

Lee said he feels grieved when seeing patients who have not managed their condition and visit the emergency room. However, he said patients must recognize the significance of primary prevention, receive appropriate treatment, medicines, and stenting, and prepare for secondary prevention to avoid recurrence.

“Your body parts will age along with you, so you need to go get checked periodically and listen to what your doctors’ advice to manage your condition, just like the parts of vehicles need to be lubricated and tightened up for maintenance,” Lee said. “Try not to skip your drugs prescribed by your doctors and keep in mind that it is important to manage the condition consistently to avoid complications.”