Study population and grouping principles
Our study enrolled patients, who had been clinically diagnosed with CHD at the department of cardiology, from hospital admissions made between June 2019 and December 2020 in our hospital. Our diagnostic criteria for CHD was consistent with the diagnostic and therapeutic guidelines of CHD from the European Society of Cardiology (ESC) published in 2013[9]. Among them, sixty patients with TVD were selected as the experimental group. Diagnostic criteria of TVD was as follows: coronary angiography showed that the diameter stenosis rates of three subepicardial vessels (left anterior descending coronary artery, circumflex coronary artery, right coronary artery) and / or their main branches were all≥50%. 60 patients with TVD were divided into two groups: 31 patients with the stenosis rate of all triple vessel coronary artery<75% served as group B (age, 45~77 years; mean age, 57.41±8.29 years; ratio of females to males: 20:11), 29 patients with all three-vessel stenosis rate≥75% served as group C (age, 44~71 years; mean age, 57.37±8.16 years; ratio of females to males: 20:9). At the same time, we recruited 30 gender and age-matched healthy subjects (age, 41~69 years; mean age, 55.43±7.54 years; ratio of females to males: 18:12) as group A. And all of the above participants were in sinus rhythm.
Exclusion criteria included: 1) therapeutic history of coronary revascularization; 2) myocardial infarction; 3) cardiac injury caused by coronary heart disease-related complications, such as papillary muscle rupture, ventricular wall rupture, interventricular septal perforation; 4) cardiac enlargement and cardiac dysfunction resulted by other types of heart disease, such as dilated cardiomyopathy, congenital heart disease, rheumatic heart disease, chronic pulmonary heart disease, valvular disease; 5) combined with hypertension, diabetes, nephrotic syndrome that contribute to heart damage. We also excluded the poor quality images.
Before the examination, we recorded the basic information of all participants on the checklist including name, gender, age, height and weight, then calculated body mass index (BMI, kg/m²) and body surface area(BSA,m2). After taking a 10 min break, a physician who was blind the purpose of the study measured the blood pressure (BP) and the heart rate (HR) of all participants. And 4 mL venous blood samples were retrieved in fasting in the morning from three groups of participants, and the serum was obtained by centrifuging venous blood at 3000 r/min for 10 min and stored in the refrigerator(-30℃). Then the content of N-terminal pro-brain natriuretic peptide (NT-proBNP) of the serum were measure by photochemical method. LV end-diastolic pressure (LVEDP) was measured by left cardiac catheterization after coronary angiography in groups B and C, and the acquisition of ultrasonic images should be carried out within two days after left cardiac catheterization.