What we call heart disease is really a systemic disease wherein the heart is affected commonly and it it noticed because it is one of the primary organs which the human and other animals cannot live without.
The brain, the lung and the liver are other vital organs. Of course arterioslerosis can affect any structure which has blood vessels, but often the heart is recognized first because it is a vital organ and there is a cause for the arteriosclerosis to develop faster in the coronary arteries.
Obviously it can develop in the brain: stroke takes place at times, large ones and small ones. It can take place in the larger arteries and we develop a blockage in the thigh, the pelvic region or the carotid arteries that conduct blood to the face and brain. It is important to remember that arterioslerosis is a systemic disease or condition.
Concerning the heart, an autoimmune irritation, an inflammatory process affects the blood vessel linings so that the endothelium does not resist blood clotting well. In areas of turbulence the blood clots more easy so most "blockages" are at bifurcations. That is why a person will have a blockage in one place and the other bifurcations are normal: there was an inordinate amount of turbulence there.
The other factor is that the heart beats within the pericardial cavity and the pericardial membrane "rubs" on the heart's exterior where the coronary arteries are located. Certain areas "rub" more due to the anatomical variation of the heart and the pericardial membranes. The friction causes "increased" inflammation of the coronary arteries, and the pericardial membrane as well also. This is subtle and chronic. The inflammation thus developed further decreases the protective ability of the lining as more autoimmune inflammatory elements attack the vessel and eventually in areas of turbulence a clot will form and adhere.
The turbulence produced tends to further develop more clot. Some clot departs and goes distal and dissolves, but some will block a small artery distally and cause a small myocardial infarction, so small, that the person may not feel anything. Many of these can degrade the heart muscle. The inflammatory reaction can cause the plaque, which is seasoned clot, as the body is always trying to fix things for the better, but this is countered by the continued inflammation.
This will, or can cause the plaque to rupture and a portion can flow distal and cause a myocardial infarction too. At times the plaque will get so meaningful the artery will nearly or completely stop flowing. The slow partial blockage harms the muscled distally and it will undergo changes and become larger: left ventricular hypertrophy, for instance. It is not caused by high blood pressure necessarily.
The inflammatory blood vessel disease causes hypertension, causes a mild autoimmune hepatitis which causes the cholesterol to rise (it doesn't cause blood vessels to plug up!), and the inflammatory blood vessel disease causes diabetes if if is severe enough when a person is young or if it is less nasty then a person can develop diabetes over time.
So, those conditions do not cause arteriosclerosis, they are concomitant conditions caused by the same underlying autoimmune disease. Cardiac arrhythmias, cardiomyopathies, and other heart problems are caused by the same systemic condition. Varicose veins are caused by it as well is rheumatoid arthritis which should be called rheumatoid disease. I have nearly finished a book titled Rheumatism, Enigma Unraveled which will be self published and will be available by May 1 via normal outlets including A.com. The book explains the above, in detail plus many, many other syndromes: conditions which medical science does not know the cause: like Alzheimer's Disease, like lupus, like autism. One underlying systemic disease that causes all those plus more. It is a unifying hypothesis or theory of disease.