Section I Standards for Coronary Artery Revascularization

Early in 2009, American Cardiology Foundation/American Cardiovascular Angiography and Interventional Society/American Thoracic Surgery Society/American Thoracic Society/American Cardiology Society/American Society of Nuclear Cardiology (ACCF/ SCAI/STS/AATS/AHA/ASNC) Jointly Released “Applicable Standard for Coronary Artery Revascularization Therapy” (hereinafter referred to as “Standard”) involving percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) ). This standard is an important supplement to the clinical treatment guidelines and helps doctors and patients to choose a reasonable revascularization treatment strategy. The “Standard” lists how to comprehensively evaluate coronary revascularization in patients with more than 180 clinical conditions, based on the anatomy of the diseased vessels, the degree of angina pectoris, drug treatment, and the risk of non-invasive examination. Not suitable or currently unclear. Factors to consider when assessing patients’ need for revascularization include: 1 clinical manifestations (acute coronary syndrome, stable angina, etc.); 2 angina severity [asymptomatic or Canadian Cardiovascular Society (CCS) class I Grades II, III, IV]; 3 Non-invasive evaluation of the severity of ischemia and whether it has certain adverse prognostic factors, such as congestive heart failure, left ventricular dysfunction, or diabetes; 4 whether drug treatment is adequate; Artery lesion anatomy (single, 2 or 3 vessel lesions with or without anterior descending or left main lesion). The standard emphasizes a comprehensive assessment of the patient’s symptoms, evidence of ischemia, and drug treatment. More specific indications for coronary revascularization include “criminal” vessels with ST-segment elevation myocardial infarction, left main disease, 3 lesions, or lesions involving the anterior descending coronary artery. For the 1 to 2 vascular lesions without involvement of the anterior descending coronary artery, or 50% to 60% of coronary vascular stenosis and chronic complete occlusion, comprehensive evaluation and careful selection are required.

2012 American College of Cardiology Foundation/American Society of Cardiovascular Angiography and Intervention/American College of Chest Physicians/American Thoracic Society/American Heart Association/American Society of Nuclear Cardiology/American Heart Failure Society/American Society of Cardiovascular Computed Tomography ( ACCF/SCAI/STS/AATS/AHA/ASNC/HFSA/SCCT) jointly updated the 2009 edition of the “Applicable Criteria for Coronary Artery Revascularization Therapy”. The new applicable standard classifies the applicability of coronary revascularization therapy as 1 to 1 At grade 9, the higher the grade, the greater the benefit of revascularization therapy; the 7 to 9 grade performance indicates that appropriate revascularization can improve the patient’s health and survival rate; grades 4 to 6 indicate whether revascularization can improve the patient’s Health and survival rates are still uncertain; Grades 1 to 3 indicate that revascularization is inappropriate and does not improve patient health and survival. If coronary artery disease does not affect the left anterior descending artery, non-invasive examinations suggest low risk or non-invasive examinations, meta-symptoms are not suitable for revascularization; if non-invasive examinations indicate moderate risk, asymptomatic, and do not receive adequate anti-angina pectoris medication, It is also not suitable for revascularization. One or two coronary artery critical lesions (diameter stenosis 50% to 60%), asymptomatic, and non-invasive test results are uncertain, even if the FFR or IVUS test is meaningful, Also not suitable for revascularization. Single coronary artery chronic total occlusion (CTO) lesions, other vessels normal, asymptomatic, non-invasive examination showed low risk, not suitable for revascularization; if non-invasive examination showed moderate risk, and did not receive adequate medical treatment is not suitable for revascularization .

For patients with coronary heart disease who are not suitable for coronary revascularization indications and/or unclear coronary heart disease, they can strengthen drug therapy, including antiplatelet, lipid-regulating, smoking cessation, diabetes control blood sugar levels, high blood pressure control and other comprehensive treatment . For such patients, enhanced external counterpulsation (EECP) treatment can achieve certain clinical benefits.

The first two section EECP therapy benefits

The principle of external counterpulsation is to drive limb blood back to the heart during diastole of the heart, drive the blood to increase diastolic perfusion of the coronary arteries, and improve myocardial ischemia. In 1980, Professor Zheng Zhensheng of Sun Yat-Sen University of Medical Sciences successfully developed the Enhanced External Counterpulsation Device (EECP) with China’s independent intellectual property rights. It was approved by the U.S. Food and Drug Administration (FDA) in 1994 and entered the US market for clinical application. In January 1998, the University of Pittsburgh, USA established the world’s first “International EECP Patient Registration Center (IEPR)” to systematically conduct basic and clinical research on EECP. In 2000, the United States Government Health and Finance Authority (HCGA) approved the cost of EECP reimbursement in Medicare (US residents over the age of 65 enjoy government-funded health insurance).

To date, several large-scale clinical trials (MUST-EECP, RECC, PEECH, and IEPR) have been conducted in the United States and in China to examine the efficacy and safety of external counterpulsation in the treatment of coronary heart disease and cardiac insufficiency related to external counterpulsation. A lot of academic materials with important research value have been obtained. These studies have confirmed that EECP can significantly improve the symptoms of angina, reduce the use of nitroglycerin, and improve exercise for patients with clinically unselected end-stage coronary artery disease (ie, drugs, intracoronary interventions, and poor coronary artery bypass grafts). But with the left ventricular ejection fraction, improve patient quality of life, 70% of patients with angina improved for more than 1 year; for stable angina patients, EECP plus drug treatment can improve myocardial ischemia, improve the prognosis of treatment after 1 year , It can promote the formation of coronary collateral circulation, and may have a preventive effect on restenosis after PCI. Up to 9 years of follow-up study also showed that the treatment of coronary heart disease patients is accompanied with EECP treatment while receiving conventional drug treatment. Can significantly reduce the risk of cardiovascular events.

In 2002, the United States ACC/AHA formally incorporated external counterpulsation therapy into the clinical treatment guidelines for coronary heart disease and angina pectoris. In 2006, the European Society of Cardiology (ESC) and the Chinese Medical Association Cardiovascular Disease Branch also successively incorporated external counterpulsation therapy into the clinical treatment guidelines for coronary heart disease and angina pectoris.

The mechanism of enhanced external counterpulsation in the treatment of angina pectoris of coronary heart disease: external counterpulsation in the ventricular diastolic phase through the sequential compression of the lower body wrapped balloon, so that increased diastolic pressure, thereby increasing myocardial blood supply, improve myocardial ischemia. On the one hand, the increase of myocardial blood flow in the process of external counterpulsation improves myocardial ischemia and relieves the symptoms of angina pectoris. On the other hand, external counterpulsation therapy accelerates arterial blood flow velocity and increases blood flow shear stress stimulation of the vascular endothelium. Improve vascular endothelial function, inhibit the occurrence and progression of atherosclerotic lesions, long-term effect is conducive to the rehabilitation of patients with coronary heart disease. It is worth mentioning that EECP has the effect of improving endothelium-dependent dilation. Qian Xiaoxian et al. found that the level of nitric oxide (NO) in blood of patients with coronary heart disease was significantly reduced, and EECP could significantly increase the level of NO. Bonetti et al. used peripheral arterial reactive hyperemia plethysmography to observe the effect of external counterpulsation in patients with coronary artery disease. It was found that external counterpulsation could improve endothelial function, and patients with significantly reduced angina pectoris were followed up for 1 month. There are still significant differences in functional improvement.

The action mechanism of in vitro counterpulsation to improve the endothelium is closely related to the increase of blood flow shear stress by external counterpulsation: 1EECP increases blood flow shear stress, restores normal endothelial function and increases NO release; 2 shear stress up-regulates endothelial cell NO synthase gene expression , increase NO synthesis; 3 inhibit the production of oxygen free radicals, reduce the inactivation of NO; ​​4 in vitro counterpulsation to increase tissue perfusion, improve microcirculation, endothelial cells to improve oxygen, functional recovery.

EECP can increase coronary blood flow, improve myocardial oxygen supply, reduce systolic blood pressure, reduce myocardial postload, and reduce myocardial oxygen consumption by increasing diastolic blood pressure. At present, there is no drug that has both therapeutic effects. EECP increases coronary perfusion pressure and promotes the establishment of collateral circulation in the ischemic region. This can not only effectively improve myocardial ischemia and hypoxia, but also help restore a lasting blood supply. Banas et al. first reported the experience of external counterpulsation in treating angina pectoris of coronary heart disease. Zheng Zhensheng of Zhongshan Medical College treated 142 patients with angina pectoris with EECP. The effective rate of symptom relief was 99.2%, and the effective rate of ECG was 62.4%. Twenty patients with positive exercise test had 45% negative conversion or improvement after treatment, and 85.2% had different physical activity ability. The degree of improvement. Du Guihai’s clinical observation of 204 patients with coronary heart disease in the EECP, the effective rate of symptoms 98%, 83.2% ECG efficiency, that external counterpulsation is a safe, effective, no side effects of treatment. EECP has enhanced cardiac function in patients with coronary heart disease. EECP can reduce myocardial ultrastructure damage in myocardial ischemic dogs. EECP can inhibit renin activity by inhibiting the expression of angiotensin mRNA, and at the same time, it can inhibit the expression of human T lymphocyte globin messenger RNA (ATGmRNA). ECP inhibits the level of angiotensin II (Ang) II, thereby protecting one of the mechanisms of ischemic myocardium.

Clinical trial physical external counterpulsation is a non-invasive and safe method for the treatment of stable angina with long-lasting benefits. Several studies have reported that external counterpulsation can improve the symptoms of angina and reduce the grade of CCS (Canadian Cardiovascular Society), reduce the frequency of weekly angina attacks, reduce the use of nitroglycerin, reduce the incidence of major adverse cardiac events, and improve quality of life. A prospective, multicenter, randomized, double-blind controlled study of external counterpulsation in the treatment of stable angina pectoris MUST-EECP (the multi-center study of Enhanced External Counterpulsation) is designed to evaluate the safety of external counterpulsation in patients with chronic stable angina pectoris and Effectiveness was jointly attended by university hospitals such as Columbia, Yale, Harvard, Pittsburgh, and Kaohsiung University San Francisco. The study showed that external counterpulsation can improve exercise tolerance, reduce the frequency of angina attacks, and reduce the amount of nitroglycerin. After 1 year of follow-up, the improvement of angina symptoms and quality of life was better than that of the control group and before treatment, and angina symptoms in 70% of patients remained unchanged for 1 year. The results of the International EEC Patent Registry (IEPR) series of studies show that EECP is reliable in both short-term and long-term outcomes in patients with coronary heart disease, and is associated with percutaneous coronary intervention (PCI) and coronary artery bypass grafting. The curative effect of makeup (CABG) may become the first-line treatment of coronary heart disease.

Data from clinical studies in China from 1996 to 2000 showed that the frequency of angina pectoris and nitroglycerin requirement, the time required for ST segment shift by 1 mm in exercise electrocardiogram, and myocardial ischemia in dynamic electrocardiogram were compared with the control group 2 months after EECP treatment. The total load, radionuclide myocardial perfusion imaging, and semi-quantitative scores of myocardial ischemia were significantly improved. Follow-up after one year of treatment: The incidence of major cardiovascular events (cardiovascular death, myocardial infarction, or re-infarction) was significantly lower in the counterpulsation group than in the control group (0.75% vs 7.34%, P = 0.012); combined endpoint events (cardiovascular The incidence of death, myocardial infarction, or re-infarction, requiring revascularization was also significantly lower in the counterpulsation group than in the control group (4.51% vs 22.02%, P<0.001); in the coronary angiography and counterpulsation group, 10 out of 10 Cases showed the formation of collateral circulation, and 1 of 11 cases in the control group showed collateral circulation. It is suggested that EECP combined with drug therapy can improve myocardial ischemia in patients with coronary heart disease with stable angina, and improve the prognosis after one year of treatment; EECP can promote the formation of coronary collateral vessels in patients with coronary heart disease; early EECP treatment for restenosis after PCI May have some preventive effect.

Yzvari et al reported 77% of patients with stable angina pectoris had improved CCS classification and echocardiographic parameters after external counterpulsation treatment. The duration of exercise plate was significantly prolonged. It was also observed that the left main coronary artery was diseased and at least one vessel was absent. Patients with genital plugs benefit better after external counterpulsation treatment. After 5 years of follow-up, the clinical symptom remission rate of patients with stable angina pectoris after external counterpulsation therapy was found to be 70% to 90%; the rate of survival and major adverse cardiac events was 64%.

In summary, patients who have clearly benefited from EECP treatment through evidence-based studies include patients with stable coronary angina (CCS grade II–IV), those who are not suitable for reperfusion (vascular remodeling), and those who have been actively treated with medications. Patients with severe, diffuse coronary atherosclerosis, persistent angina, and resting ischemia burden after coronary reperfusion therapy. With the increasing awareness of the prevention and control of chronic cardiovascular disease at home and abroad, EECP, a traditional Chinese characteristic technology, has begun to receive more and more attention, and in chronic ischemic diseases (including ischemic stroke, etc.) In the prevention and control of the disease, its unique therapeutic and adjuvant therapeutic effects are exerted. Therefore, EECP therapy not only does not conflict with modern treatment options for coronary heart disease, but it is also an important choice for medical care at the grassroots level and in the community due to its unique advantages such as safety, efficacy, and ease of operation.

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