Hu Dayi: Asymptomatic, how to face the narrowing of blood vessels found by coronary artery CT?

Coronary CT is beneficial for early detection of coronary artery disease and early prevention and control. However, not all adult physical examinations require CT at the time of the physical examination. CT is mainly used for screening patients with moderate risk of coronary heart disease, such as middle-aged patients with hypertension, diabetes, dyslipidemia, smoking, obesity risk, and should not be used for patients with low risk of coronary heart disease. In particular, for women without the above risk factors and with normal menstruation, CT examination is not only useless, but also brings an increased risk of lifelong cancer, which is more harmful than that of men of the same age and women of the same age.

In recent years, coronary CT has been done generically. Many asymptomatic patients, the physical examination of coronary CT, found one branch or multiple branches of the coronary blood vessels or multiple stenosis of different degrees. One of the birth defects of Western medicine is "demarcation", which defines the light, medium and severe "lesions" according to the degree of narrowing of the lesion. The degree of stenosis is less than 50%, that is, it is classified as mild, 50%-70% is moderate, and more than 70% is severe.

Clinical ct is an imaging department, the current imaging doctor or technician lacks clinical training and basic skills, and the report is written on the same as the recommendation to do coronary angiography. Coronary angiography is the "gold standard" for diagnosing coronary heart disease and has become a household name.

Contrast is reported as severe coronary stenosis if it shows stenosis of 70% or more. For many years, doctors only used the criterion for stenting based on the degree of stenosis of blood vessels. As a result, things such as my Fellow Students of Beijing Medicine in the local hospital according to the contrast report, the middle of the former branch reduction of 71% (I don't know if it is really only more than 70% of the degree of 1%) was put on the stent that did not need to be done at all, and I regretted it afterwards.

I would like to tell you that if there is no chest discomfort during normal exercise, such as walking fast, going uphill, going upstairs, or even running, climbing, playing basketball, the physical examination is coronary CT, no matter how narrowing is reported, do not easily agree to hospitalization for coronary angiography, and it is not believed that only according to the degree of vascular stenosis, you can agree to receive stent surgery. Due to asymmetric medical information, patients who see report severe stenosis of blood vessels are often prone to sign informed consent to receive stents or even bypass surgery. The stenosis of the blood vessels was severe, and as soon as the doctor mobilized, he agreed to the operation. This absurd criterion of placing stents based solely on the degree of stenosis of blood vessels has led to the overuse of stents and harmed the interests of many patients.

When it comes to the degree of stenosis, the most serious is 100% stenosis, but if there are no chest discomfort symptoms in the above exercises, you don't have to undergo stent surgery right away!

What is the reason for finding 90% or even 100% of the blood vessels to be asymptomatic and found to be narrow? Why are blood vessels severely narrowed, but clinically patients do not feel uncomfortable (symptoms)?

The most common cause, these severe stenosises are gradually and slowly formed over many years. During the slow development of lesions, the body has a strong compensatory self-protection mechanism - the formation of collateral circulation, that is, no narrowed or lightly narrowed blood vessels emit new blood vessel branches, helping the narrowing to worsen until the completely occluded blood vessels supply blood to the myocardium, which can be understood as "self-bypass".

Less commonly, the cause is that some myocardial infarction occurs when the symptoms are not obvious or the duration is short, and when it occurs without the attention of the patient, it gradually stabilizes and becomes an old myocardial infarction.

How do you identify these two situations? Very simple, one is an electrocardiogram, and the other is an echocardiogram. In patients with severe vascular stenosis or chronic complete occlusion with rich collateral circulation, both ECG and echocardiography are normal. Abnormalities (abnormal Q waves) may be seen on the ECG of patients with old myocardial infarction, and partial contraction of the myocardium of the infarction may be seen on echocardiography. Even if there is a myocardial infarction, if it is obsolete and in a stable period, there is no rush to do the stent immediately. Attention should be paid to the site of myocardial infarction reflected by ECG and echocardiogram, the extent of myocardial damage, and the impact on cardiac function, especially whether the left ventricular end of diastolic end is enlarged or the left ventricular ejection fraction decreases, and corresponding drug treatment and rehabilitation are carried out.

Acute myocardial infarction often has acute onset of persistent chest tightness chest pain, to the hospital emergency department or in the ambulance to record the ECG will have typical changes, blood tests reflect the increase in myocardial damaged troponin, at this time, as long as there is no risk of bleeding or contraindications, stents are the best choice to save the myocardium, save lives, time is the myocardium, time is life. The earlier the stent is done, the more fully the myocardium is saved, and the more timely the stent opens the blood vessels of thrombotic occlusion, the greater the hope of saving lives.

However, for patients who do not have symptoms during usual exercise, stents cannot prevent myocardial infarction or sudden cardiac death. Measures to prevent these cardiac emergencies: one is to change an unhealthy lifestyle, smoking cessation is very important; the other is to control risk factors: high blood pressure, diabetes, to reduce LDL cholesterol to 1.8, or even 1.4mmol/L or less.

Asymptomatic patients who have done CT to find vascular stenosis, in addition to the ECG and echocardiogram mentioned above, can do exercise load ECG, young and middle-aged people can choose to run a flat plate, and the elderly can choose a fixed bicycle. Increased heart rate during exercise, recording changes in myocardial ischemia on ECG, and paying attention to the level of heart rate when myocardial ischemia occurs are beneficial for guiding the prescription of rehabilitation exercises in the future. Even if the results of the exercise test are positive, they are not indications for stents, in addition to lifestyle changes and control of risk factors, under the guidance of a doctor, the rational use of drugs beneficial to the control of myocardial ischemia can be used, and exercise training can be done in the cardiac rehabilitation center system. Aerobic exercise is beneficial for collateral circulation formation, which helps reduce control myocardial ischemia.

Non-invasive, low-cost extracorporeal counterpulsation is also beneficial for controlling and reducing myocardial ischemia.

For stable coronary heart disease or coronary atherosclerosis, the role of stents is to improve symptoms of angina, not to reduce myocardial infarction and cardiovascular death, nor to reduce overall mortality.