Causes of Coronary Artery Disease
Coronary artery disease develops when your coronary arteries (the major blood vessels that supply your heart with blood, oxygen, and nutrients) become damaged or diseased. Over time, cholesterol and fatty deposits (called plaques) can build up on the inner walls of your arteries. These plaques restrict blood flow to your heart by clogging the artery or causing the artery walls to “harden” and malfunction.
When plaque decreases blood flow to your heart, your heart doesn’t receive the oxygen and vital nutrients it needs to work properly. This usually causes chest pain (angina). When blood flow through a coronary artery becomes severely restricted or the artery suddenly becomes blocked, the heart muscle that it supplies can die, which is what causes a heart attack (myocardial infarction). The affected portion of the heart muscle turns to scar and is no longer able to contribute to normal heart function.
Because coronary artery disease often develops over decades, it can go unnoticed until you have a heart attack.
Risk factors for coronary artery disease include:
- High blood pressure
- High LDL (bad) cholesterol
- Low HDL (good) cholesterol
Having a sedentary lifestyle (limited activity or exercise) can increase your risk of developing coronary artery disease because it often leads to some of the conditions listed above.
Your risk for heart disease also grows as you age due to genetic (runs in your family) or lifestyle factors that cause plaque to build up in your arteries. By the time you reach middle age, enough plaque may have built up to begin causing warning signs or symptoms. According to the National Heart, Lung, and Blood Institute (NHLBI), the risk for heart disease in men increases after age 45; in women, the risk increases after age 55.
Family history of heart disease also increases your risk. If your father or a brother was diagnosed with heart disease before age 55, or if your mother or a sister was diagnosed before age 65, you have a greater risk of being diagnosed with heart disease, according to NHLBI.
Although older age and a family history of early heart disease are risk factors, you can reduce your own chances of developing the disease by controlling other risk factors, such as your weight, blood pressure, and cholesterol levels.
If you are worried that you may be at risk for heart disease, be sure to talk with your doctor about ways to reduce your risk. And be sure to speak with you doctor before starting any exercise program to decide what is right for you.
Diagnosis and Treatment Options
Your doctor usually can diagnose coronary artery disease based on your medical history, risk factors, a physical exam, and the results from tests and procedures.
There is no one test that can diagnose coronary artery disease, so your doctor may recommend one or more of the following: electrocardiogram (EKG), stress test, echocardiogram (echo), chest x-ray, blood tests, and coronary angiography. For more information on these tests, visit our common diagnostic tests page.
The most common treatments for coronary artery disease include coronary artery bypass grafting (CABG) surgery or percutaneous coronary intervention (PCI). Both treatment options will restore blood flow to your heart, but there is no one treatment guaranteed to be effective for all patients. In general, both CABG and PCI are designed to help patients with coronary artery disease leave longer by decreasing the likelihood of suffering a heart attack. These procedures also are very effective at improving the symptoms of coronary artery disease.
Talk with your doctor or cardiothoracic surgeon to get more information on both treatment options and choose the one that is best for you. You can print these sample questions to use as a basis for discussion with your doctor.
You also can access the STS Risk Calculator, which can help calculate your risk of death or other complications from certain types of heart surgery. The results can help you and your doctor to determine the best course of treatment.
CABG surgery (often pronounced “cabbage”) is the most commonly performed heart operation in the United States. A cardiothoracic surgeon will make an incision down the front of your chest, through your breastbone or sternum. This incision is called a median sternotomy, and it enables the surgeon to see your heart and aorta.
The operation is designed to bypass the blockages in your coronary arteries in order to restore blood flow to your heart. Some patients need only one bypass graft, but most people who are candidates for CABG have blockages in several of their coronary arteries and may need between three and five bypass grafts.
During the operation, your surgeon will take a healthy blood vessel (artery or vein from your body), usually from your leg, arm, chest or abdomen, and connect it to the other arteries (usually the aorta) in your heart. This enables blood flow to “bypass,” or go around, the diseased or blocked portion of your coronary artery, creating a new path for blood flow to your heart.
A heart-lung machine (sometimes called “the pump”) typically is used during the operation. The machine temporarily takes over the function of your heart and lungs during surgery to maintain blood circulation and oxygen flow through your body. After the surgery is completed, you will be taken off the pump, and your heart and lungs will resume normal function. Some surgeons prefer to do the surgery without the heart-lung machine, which is called “off-pump.” Your cardiothoracic surgeon will tell you the technique that will be used for your individual operation and provide additional detail.
CABG surgery generally takes between 3 and 6 hours and requires that you be put under general anesthesia. Following surgery, you likely will spend one night in an intensive care unit followed by another 3 to 5 days in the hospital before going home.
Although it is possible for symptoms to recur after surgery, many people remain symptom-free for as long as 10 or 15 years. CABG surgery also can lower your risk of having a heart attack.
CABG has been proven to be safe and effective, but like all heart procedures, it can result in serious complications. The chance of a major complication (stroke, heart attack, kidney damage, bleeding, etc.) depends on your age and overall health going into the operation. Although CABG can be performed safely in patients in their late 80s and early 90s, risk for complication increases with age. Many patients also may require blood transfusions during or after the operation.
PCI, sometimes referred to as angioplasty, is a nonsurgical procedure that can open blocked or narrowed coronary arteries. A thin, flexible tube with a balloon or other device attached to the end will be threaded through one of your blood vessels up to the affected artery. Once in place, the balloon is inflated to create a larger opening and restore blood flow through the artery.
During the procedure, you may also have a small mesh tube, called a stent, placed into your artery. The stent helps prevent further blockages.
One benefit of PCI is that it is much less invasive than CABG because it does not require a surgeon to make an incision in your chest. which reduces your recovery time. PCI usually is limited to patients who have fewer blocked arteries. Stents also require blood-thinning medication, may not last as long as surgical treatment, and are not possible or recommended in certain areas or blockages of the heart.
You may be able to manage your coronary artery disease through lifestyle changes and medications. A conversation with your doctor can help you decide what treatment is best.
Even if you do not require surgery or PCI, incorporating healthy behaviors will help prevent further damage to your heart.
CABG surgery is a major operation, and you should expect to be in the hospital for about a week after surgery. Your hospital stay likely will include a day or two in the intensive care unit (ICU) where hospital staff can monitor your blood pressure, breathing, and other vital signs. You also will have a breathing tube for a few hours or possibly overnight, so communication will be difficult. The breathing tube will be removed as soon as you are awake and able to breathe on your own.
Most patients can be discharged from the hospital within a week, but recovery continues at home. This is an individual process that is affected by your age and general health status, but most patients initially need to modify some activities and require a few weeks to re-gain energy levels. Often a period of 'cardiac rehab' or working out at a designated gym a few times a week for reconditioning is recommended. Many patients can return to work within 4-6 weeks, but this depends on the type of job and general recovery progress. Your doctor will provide individualized recommendations for your full recovery.
If you underwent PCI to open your arteries, you likely will have a shorter recovery period. Speak with your doctor to find out more about what to expect during recovery.
Reviewed by: Emily A. Farkas, MD and Fernando Fleischman, MD