Coronary Artery Disease
Question: I am a 50 year old man who has recently been told that I have coronary artery disease, can you please enlighten me about the risk factors, indications for surgery, risks and types of bypass grafts that are available? -- Adam S.
Coronary Artery Disease (CAD) is one of the leading causes of death in the US. Approximately 300,000 coronary surgeries are performed in the US / each year. Also, approximately 250,000 Percutaneous Transluminal Coronary Angioplasties (PTCAs) are performed in the US / year. Coronary artery disease is caused by atherosclerosis of the vessels that supply blood to the heart. This can cause a complete blockage of the vessel or a partial obstruction called a stenosis. Ischemic disease involves areas of the heart at risk for a myocardial infarction because of a significant stenosis proximally. This can give the classic signs of chest pain or angina pectoris.
Risk factors for developing coronary artery disease include:
- family history (genetic)
- diabetes mellitus (elevated blood sugar)
- hypertension (high blood pressure)
- hypercholesterolemia (elevated cholesterol)
Indications for Coronary Artery Bypass Grafting (CABG) include:
- unstable angina
- Left Main coronary disease
- multiple vessel disease with crescendo angina refractory to medication
- high grade proximal LAD disease
- post-infarction angina
- complication of myocardial infarction (ventricular wall rupture, ventricular septal defect, papillary muscle dysfunction--acute mitral regurgitation).
- complication of failed PTCA.
The most commonly asked statistics for a patient undergoing CABG surgery are:
- operative mortality 1-3%
- myocardial infarction immediately after surgery 3%
- post-operative wound infection 3%
- post-operative bleeding 3-5%
- post-operative heart arrhythmias 30%
There are different types of grafts or conduits that can be used to bypass the blockages in the heart. The most commonly used grafts are the internal mammary artery (an artery that normally lies under the chest cavity) and the saphenous vein (a vein in the leg). The one-year patency rate for the internal mammary artery is 96% and the long-term patency is excellent. The saphenous vein has a one year patency of 86%. Other possible conduits include the radial artery with a 90% 1-year patency.
More info: Patient's Guide to Heart Surgery--Coronary Artery Disease