MMP9 and acute coronary syndrome: MMP-9 is an important factor promoting the development of atherosclerosis, and its level reflects the formation of atherosclerosis and plaque stability; IL-4 and IL-6 act as proinflammatory factors, and their elevated levels reflect the progression of atherosclerosis to a certain extent; hs-CRP is a nonspecific inflammatory factor secreted by the liver, and studies have pointed out [13] that its elevated level is related to the occurrence, development, and prognosis of acute coronary syndrome, and is an important inflammatory factor in the development of atherosclerosis.