Does high levels of salt contribute to coronary artery disease?

Not really: High salt intake will have an impact on fluid retention and blood pressure and as such play a role in the dynamics of blood flow in your arteries as well as trigger a few, expected, hormonal responses to deal with the salt load and thus possibly contribute to the development of plaques, but there is no direct imapct of salt on the plaque in the arteries.

Indirectly: High salt intake, in some people, is associated with development of high blood pressure, hypertension. High blood pressure is an important factor in the development of atherosclerosis and coronary artery disease.

Not generally: Many, many studies have failed to show a clear correlation between sodium ("salt") consumption and cardiovascular mortality. At levels > 7gm per day, by the governments own data is when most significant effects occur for those without sodium sensitive conditions like congestive heart failure. The average american consumes about 3400mg/day. The biggest source to dietary sodium is preprocessed food.