Transcriptional activity of metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1) genes differentiates healthy subjects (with coronary artery disease excluded in coronary angiography) from patients with coronary artery disease without heart insufficiency and patients with coronary artery disease complicated by heart failure. Here, MMP9 is linked to coronary artery disorder.