To use left ventricular global longitudinal strain as a means of monitoring myocardial exercise function during anaesthesia in patients with coronary artery disease, to explore the association with the occurrence of postoperative myocardial injury, and to perform a predictive study of postoperative myocardial injury. The study was designed according to a prospective follow-up cohort.

The incidence and risk of postoperative myocardial injury in patients with coronary artery disease is high, and there is no definitive monitoring tool to predict postoperative myocardial injury. Speckle tracking imaging (STI), which quantifies strain and ventricular torsion in all segments of the heart, is more sensitive to subtle changes in myocardial contractility than conventional ultrasound. This project proposes to use 4D-STI as a means of monitoring myocardial exercise function during anaesthesia in patients with coronary artery disease, to explore the association with the occurrence of postoperative myocardial injury, and to perform a predictive study of postoperative myocardial injury. The study was designed according to a prospective follow-up cohort. The protocol was developed with reference to the STROBE guidelines for cohort studies. In this study, 2.5 ml of venous blood specimens were collected before surgery and at the end of surgery and sent to the laboratory. Intraoperative data collection was performed in the operating theatre and follow-up was obtained on the ward and during telephone follow-up.

Inclusion Criteria:

1. Age 65-90;
2. According to the European Heart Association's diagnostic criteria for chronic coronary syndrome in 2019.Patients with suspected coronary heart disease and stable angina pectoris, with or without dyspnea; New heart failure or left ventricular dysfunction, suspected coronary heart disease; Patients with acute coronary syndrome who are asymptomatic or stable within one year of onset, or who will undergo revascularization in the near future;Patients with an initial diagnosis or revascularization for more than one year, with or without symptoms; Angina pectoris, suspected vasospasm, or microvascular disease patients; During screening, asymptomatic people with coronary heart disease were discovered;
3. ASA II~III; NYHA II~III; require general anesthesia;
4. no history of anesthetic allergy;
5. agreed to participate in the study and signed the informed consent form.

Exclusion Criteria:

1. Congenital heart disease, severe ventricular arrhythmia, atrial fibrillation, severe valvular regurgitation;
2. Severe history of chronic obstructive pulmonary illness (COPD severity III or IV), individuals with severe or uncontrolled bronchial asthma, pulmonary infection, bronchiectasis;
3. Patients with persistent drinking and known or suspected abusers of other narcotic analgesics;
4. Obese (BMI 30 kg/m2)
5. Cardiac surgical procedures are planned.

According to the European Heart Association's diagnostic criteria for chronic coronary syndrome in 2019, refers to the many stages of coronary heart disease other than the clinical manifestations dominated by acute coronary thrombosis.

The individual participant data for this study is available from the sponsor on reasonable request through email.

Within five years