Is the stent implant a permanent solution? Here are some facts about heart stent implants

Many people have misunderstandings about heart stents. Are the more expensive the stent, the better? Is installing a stent a "once and for all" solution? This article will answer your questions about heart stents.

Written by reporter Song Meng (Medical and Health Group) Graphic editor: Chen Yongjie

New Media Editor/Chen Xuanzhi

Interview experts:

Zheng Zhi (Deputy Chief Physician, Department of Cardiovascular Surgery, Tongji Hospital, Wuhan)

Recently, the news that the average price of heart stents dropped from 13,000 yuan to 700 yuan has attracted widespread attention. Some people jokingly said that the heart stents were "soul-bargained." The public not only doubts the quality of the heart stents after the price reduction, but also still has many questions and misunderstandings about stents.

▍One of the three major methods for treating coronary heart disease

Zheng Zhi, deputy chief physician of the Department of Cardiovascular Surgery at Wuhan Tongji Hospital, said that heart stents, also known as coronary stents, are devices used in percutaneous coronary intervention (PCI) and are an important treatment for effectively improving the symptoms of patients with coronary heart disease and significantly reducing the mortality rate of patients with acute myocardial infarction. Heart stents are one of the three main methods of treating coronary heart disease, the other two being drugs and bypass surgery.

▲Comparison of normal arteries and atherosclerotic arteries (picture from the Internet)

According to statistics, China is a country with a high incidence of coronary heart disease. From 2009 to 2019, the number of patients with coronary heart disease increased from 230,000 to more than 1 million. Correspondingly, the annual growth rate of heart stent interventional surgery is more than 10%. According to the 2019 China Cardiovascular Health and Disease Report, nearly 1 million people in China receive stent treatment every year.

Zheng Zhi said that coronary heart disease is mainly caused by the stenosis or occlusion of the coronary arteries, which are the blood vessels that supply blood to the heart. The pathogenic mechanism is just like the scale formed by impurities in water blocking pipes. Excessive unconsumed cholesterol in the body is deposited on the blood vessel walls, forming plaques, causing atherosclerosis, and even blood vessel stenosis, so that the amount of blood flowing to the heart cannot reach the normal level.

Among them, as the degree of vascular stenosis increases, the possibility of plaque rupture and thrombosis blocking the blood vessels also increases. The only treatment for coronary heart disease in the early stage is drug therapy, and drug therapy cannot change the stenosis of blood vessels.

It was not until 1977 that a German doctor performed surgery on a patient with coronary heart disease and proximal stenosis of the left anterior descending artery using a special balloon he made to dilate the coronary arteries. The doctor improved the patient's vascular stenosis (the patient responded well after the surgery), thus opening a new era in the treatment of coronary heart disease.

However, the main problem of early interventional surgery is that postoperative acute occlusion (deposited plaques fall off and block small blood vessels, which may cause acute diseases) is as high as 3%, and the postoperative restenosis rate is as high as about 30% to 50%. In other words, even if the patient has surgery, there is a possibility that the interventional effect will be affected. Scientists have been conducting relevant research to reduce the incidence of postoperative acute occlusion. It was not until the 1980s that coronary stents were invented and came into being.

With the development of science and technology, scientists in the 21st century have discovered that anti-proliferative drugs can be loaded on the surface of stents, which may reduce the restenosis rate to below 10%. In addition, in September 2001, the first clinical trial of drug-eluting stent (DES) was announced at the annual meeting of the European Society of Cardiology, which also revealed that a new chapter has been opened in the interventional treatment of coronary heart disease.

Zheng Zhi said that currently, the mainstream of heart stents is the third-generation drug-eluting stent (DES), which is covered with a polymer coating with good biocompatibility. The coating contains anti-proliferative drugs, which can be slowly released after the stent is placed to inhibit tissue hyperplasia caused by the metal stent and prevent restenosis in the stent.

▲Heart stent (picture from the Internet)

Among the many cases of heart stent surgery, it is worth mentioning that former US President George W. Bush was diagnosed with coronary heart disease in a hospital in Dallas, Texas in 2013 and successfully underwent heart stent surgery.

Zheng Zhi said that in clinical practice, most heart stents are made of mesh structures made of stainless metal materials, and there are invisible micro-holes on the stents made by lasers. Generally, the length of the stent is 8mm to 36mm, the diameter is 2.25mm to 4mm, and the wall thickness is 90μm to 120μm. Various models can be used to adapt to blood vessels of different thicknesses and lesions of different lengths.

In addition, heart stents can also be loaded with drugs that prevent restenosis through carriers. After being placed in blood vessels, the carriers release the drugs, thereby preventing restenosis of the blood vessels.

"Heart stents are mainly used in percutaneous coronary intervention (PCI). In theory, percutaneous coronary intervention should only be considered a minimally invasive interventional treatment," said Zheng Zhi.

Because patients do not need to undergo open-chest surgery, they only need to make a small incision in the hand or thigh, and then insert a catheter from the peripheral artery to the opening of the heart blood vessel. The stent is then sent along the catheter to the diseased part of the blood vessel, and the stent is released to prop up the narrowed diseased blood vessel, compress atherosclerotic plaques, and increase blood flow.

Compared with heart bypass surgery, heart stent surgery has the advantages of short operation time, small surgical incision, and repeated placement, making it an important means of treating coronary heart disease.

Moreover, the current guidelines for the diagnosis and treatment of coronary heart disease in various countries point out that for some patients with severe coronary artery disease, stent treatment is recommended as the first choice.

▍Installing a bracket is not a one-time solution

When interviewing other cardiology experts, the reporter learned that for coronary heart disease, the main means of treating the disease is heart bypass surgery or heart stent surgery, but stents are not suitable for all coronary heart disease patients.

An article about heart stents from the Chinese government website pointed out that stent surgery is suitable for patients aged 30 to 65 years old who have been diagnosed with stenosis with a blockage of more than 75% after coronary angiography, who often suffer from myocardial infarction, and who are aged between 30 and 65 years old.

In addition, some experts have said in media interviews that the success of heart stent surgery does not mean that coronary heart disease is cured. Heart stent surgery is only one of the most effective ways to solve local coronary artery stenosis. Active drug treatment and improvement of lifestyle are the most basic.

▲Schematic diagram of heart stent (picture from the Internet)

Moreover, stent implantation is not without risks. There are certain risks during and after the operation, such as intraoperative bleeding, operation-related vascular damage, postoperative thrombosis or intimal hyperplasia in the stent, causing stent stenosis and blockage, etc.

In addition, implanting a stent does not mean you can rest assured after the operation. If the symptoms improve after the stent is placed, but the patient does not take medication regularly and take active preventive measures, the stent will not be able to play a big role.

In addition, regular follow-up examinations are required after surgery. Professor You Shijie of the Department of Cardiology at Beijing Fuwai Hospital once said in an interview with the media: Generally, follow-up examinations should be conducted 1 month, 3 months, 6 months and 12 months after interventional treatment. It should be emphasized that all patients need to improve their awareness of prevention, comprehensive prevention awareness and continuous prevention awareness.

Some experts also pointed out that no matter what the reason, if the patient has suspicious heart symptoms such as chest pain and chest tightness, they should be re-examined at any time. The purpose of this is to clarify whether there are any side effects of medication after surgery, whether there are any side effects caused by stents, etc.

Of course, the indications have been strictly regulated in China. Therefore, whether or not to implant a stent and how many to implant should be determined based on the specific situation. After all, everyone's physical condition is not necessarily the same.

▍Misunderstandings about heart stents

Many patients have misunderstandings about heart stents. For example, some patients believe that the more expensive the stent, the better. In fact, this is a wrong concept.

Relevant experts pointed out that stent placement is the same as taking medicine. The key is to choose the most suitable one. Doctors will choose different stents according to the characteristics of the lesion. For example, some stents have longer models, some stents have stronger support, and some stents can pass through twisted lesions, etc. Whether it is domestically produced or imported is not necessarily the main consideration.

The effectiveness of treatment is related to the stent, but more importantly, the operation technique. If the expensive stent is not placed properly, the effect will not be good.

▲ Patients have misunderstandings about heart stents (Picture from the Internet)

Although the cost of coronary artery intervention surgery may be reduced in the future, patients may still be thinking: Can they live without worries after the surgery? In addition, some patients are worried that they will not be able to do anything after the stent is placed.

In fact, the stent itself does not affect the patient's ability to do any activities or work, and the stent will not shift or fall off due to activities. On the contrary, those patients who did not place the stent in time during the acute stage of myocardial infarction, resulting in large-area myocardial necrosis, may be unable to do anything due to heart failure. Or those patients with severe angina pectoris that cannot be controlled by drugs may have their quality of life affected by repeated angina attacks.

Of course, not all coronary heart disease patients need stents, but those who need stents should not delay themselves or their loved ones because of believing in rumors. Some people are worried that China is suspected of abusing stents. In fact, the number of stents installed per person in China is currently 1.45, which is consistent with the data in Europe and the United States.

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