Abstract: In this study, 124 patients with coronary heart disease were selected as the study group, and 124 patients who were suspected and excluded coronary heart disease by coronary angiography were selected as the control group. Color Doppler echocardiography were carried out on both groups. It was found that the contrast filling rate (β) and the maximum number of microbubbles (A) in the study group were lower than those in the control group, while serum homocysteine (Hcy) and proprotein convertase subtilisin 9 (PCSK9) levels were higher than those in the control group (P<0.05). It was also found that β, A, serum Hcy, PCSK9 were important influencing factors of coronary heart disease. The combination of β, A, serum Hcy and PCSK9 showed good efficacy in the diagnosis of coronary heart disease. The number of coronary artery lesions and the degree of stenosis in patients with coronary heart disease were negatively correlated with β and A values, and positively correlated with serum Hcy and PCSK9 levels (P<0.05). Therefore, the authors believe that β, A combined serum Hcy and PCSK9 have high application value in the diagnosis of coronary heart disease. These indexes are important influencing factors for the occurrence of coronary heart disease, and have good linear relationship with the number of coronary artery lesions and the degree of stenosis.

Key words: coronary heart disease, ultrasound contrast, homocysteine, proprotein convertase subtilisin 9, degree of coronary artery disease, diagnosis