Causes of coronary artery atherosclerosis include high blood pressure, diabetes, high cholesterol levels and smoking, according to Mayo Clinic. These causes damage the inner layer of the coronary artery, causing accumulation and rupturing of fatty deposits or plaques, which can cause a heart attack due to clumping of the platelets.
Increased levels of low-density lipoprotein and decreased levels of high-density lipoprotein can cause high levels of cholesterol in the blood, leading to plaque formation and atherosclerosis. High blood pressure also causes thickening, hardening and narrowing of the coronary artery. Additionally, carbon monoxide from smoking damages the inner lining of the coronary artery, increasing the risk of atherosclerosis, explains Mayo Clinic. Formation of plaque in the arteries also increases with age, interfering with blood flow through the arteries, notes Healthline.