What can be done to prevent further complications of atheromatous artery, currently the patient has MILD ENLARGEMENT OF THE HEART.

Is BP high? It all depends on the degree of obstruction of that (and other) arteries. GENERALLY, a low fat diet, active lifestyle, blood pressure control, and statin drugs are recommended to prevent heart attacks; your doctor may add several other things, based on the medical history. But it takes more than just a single atheromatous artery to cause heart enlargement. Is blood pressure high?
Healthy lifestyle. I don't know the patient's age , this patient already has atherosclerosis with anatomic changes noticed on the cardiomegaly, Patient need to have a cardiac diet , control blood pressure if HTN , control bs if diabetic , and have a statin to lower levels of lipids , cause of atherosclerosis , in some studies , even show reversal of atherosclerosis and also exercise oriented by your primary md.