Causes & Risk factors
Atherosclerosis initiates as the fatty streak or plaques which appear initially in the aorta and coronary vessels. This appears on the inner vessel wall with deposits of fat. The plaque may also have protein and fibrous deposits. The plaques develop their own microscopic blood vessels known as vasa vasorum. Several theories have been put forward to describe the reasons for development of the plaques including injury of the arterial wall and the damage caused by accumulation of free radicals due to oxidative stress. Atherosclerosis is a chronic condition that develops over a period of time. The plaque might rupture with formation of clots and further narrow the flow of blood in the coronary vessels. The obstruction of the vessels due to the plaques leads to conditions of insufficiency in the heart muscles and resultant ischemic conditions and coronary artery syndromes.
Atherosclerosis increases with age. Men are more at risk of developing heart disease than pre-menopausal women. Menopausal women with a history of oral contraceptives who are over the age of 35 and are smokers are at greater risk. Studies have proven a higher risk of heart disease among those with a familial history of premature heart attacks.
Chronic conditions such as hypertension and type II diabetes can progressively worsen CAD with changes in the heart muscles and coronary blood vessels. Obesity is also one of the leading causes of CAD which can in turn affect hypertension and diabetes. This may promote atherosclerosis. Smoking emerges as an independent risk factor as seen from several studies. Chronic kidney conditions can also affect the development of CAD. A high level of apoprotein B also predicts development of CAD.