Do you know about Coronary Artery Disease?

Author: Ding Keke, deputy chief physician of Shanghai Tongji Hospital

Reviewer: Liu Xuebo, Chief Physician, Shanghai Tongji Hospital

The coronary artery is the blood vessel that supplies blood to the heart. Under normal circumstances, the coronary artery is divided into two branches, namely the left and right coronary arteries that respectively issue from the left and right coronary sinuses of the aorta. The left coronary artery consists of a main trunk, the left main trunk (LM), and its branches, the left anterior descending branch (LAD) and the left circumflex branch (LCX), which are then divided into branches at various levels; the right coronary artery (RCA) is relatively simple, and its main branches include the conus branch, right marginal branch, sinoatrial node branch, posterior descending branch, etc.

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1. What is coronary artery disease?

Coronary artery disease, in a broad sense, can be anatomical abnormalities such as the opening, course, and termination of the coronary arteries. It can also be inflammation, atherosclerosis, stenosis, spasm, dissection, and other problems. It can be a problem with large vessels or microcirculation, and it can be a functional problem or an organic problem.

Coronary atherosclerotic heart disease (CHD) is the most common coronary artery disease. It is mainly caused by atherosclerosis of the coronary arteries, which leads to stenosis or occlusion of the lumen, and then causes heart disease such as myocardial ischemia, hypoxia or necrosis.

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Anomalous origin of coronary arteries (AOCA) is also a type of coronary artery disease, which is mainly manifested by abnormalities in the number, location, and course of coronary artery openings. It is generally believed to be caused by abnormal or incomplete development of the coronary arteries during the embryonic period. For example, the right coronary artery should open in the right coronary sinus but opens in the left coronary sinus, the right coronary artery originates from the left side, myocardial bridges, coronary artery-pulmonary artery fistulas, etc. These may cause myocardial ischemia, resulting in symptoms such as chest tightness and chest pain, but resting electrocardiograms, cardiac ultrasound and other examinations may not be able to find the problem.

2. How is coronary artery disease diagnosed?

When you have symptoms such as chest tightness and chest pain, and no problems are found after electrocardiogram, myocardial injury markers and other tests, and highly suspect coronary artery abnormalities, doctors usually first recommend coronary CT angiography (CTA), and if necessary, coronary angiography (CAG). Coronary angiography is the gold standard for diagnosing coronary artery disease, but it is an invasive examination with certain indications and contraindications. In addition, intravascular ultrasound (IVUS) and optical coherence tomography (OCT) can also be used to diagnose coronary artery disease.

3. Treatment of coronary artery disease

Coronary artery disease has different treatments depending on the cause and clinical manifestations. For the most common coronary heart disease, the main treatments include:

(1) Control risk factors, such as controlling high blood pressure, high blood lipids, and high blood sugar, quitting smoking, limiting alcohol consumption, and making lifestyle changes, including diet and exercise;

(2) Delay the progression of atherosclerotic plaques and stabilize endothelial function by taking aspirin, statins, colchicine and other drugs that reduce inflammatory responses;

(3) To relieve symptoms, such as angina pectoris, you can use nitroglycerin, isosorbide dinitrate, etc.

(4) For severe blockage of the coronary artery that affects hemodynamics, it can be treated through interventional therapy (balloon dilatation, stent implantation, etc.) or surgical procedures.

Some patients have a history of hypertension, diabetes, obesity, smoking, etc., and sometimes feel chest tightness, but they don't care. After a coronary artery CTA, it was found that the blood vessels were severely narrowed, with a stenosis rate of about 70%. Is it necessary to implant stents for such patients? First of all, it depends on the symptoms and signs, such as frequent chest pain attacks and high levels of myocardial enzymes. This situation usually indicates that the plaque is unstable, and interventional treatment (stent implantation, balloon dilatation, etc.) is generally recommended; if the situation is not so urgent, further examination of blood flow reserve function, etc. can be performed, and appropriate treatment can be given after comprehensive evaluation. Therefore, the degree of coronary artery stenosis is not the only criterion for stent implantation.

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In addition, if there are unstable plaques in the coronary arteries, they are like dumplings with thin skin and rich fillings, which are easy to break and can cause myocardial infarction or even sudden death; severe stenosis, calcification, tumor-like dilatation of blood vessels, etc. will increase the difficulty of treatment.

In short, the diagnosis and treatment of coronary artery disease should be based on the patient's medical history, symptoms, signs, myocardial injury marker levels, cardiac ultrasound, and coronary artery CTA or angiography results. In addition, regular follow-up after treatment is equally important.