An overview of Coronary Artery Disease

Coronary artery disease (CAD) develops when the coronary arteries become too narrowor cholesterol blockages develop in the walls. The coronary arteries are the bloodvessels that supply oxygen and blood to the heart.

CAD tends to develop when cholesterol builds up on the artery walls, creatingplaques. These plaques cause the arteries to narrow, reducing blood flow to theheart, or can cause inflammation in and hardening of the walls of the blood vessel.A clot can sometimes obstruct blood flow, causing serious health problems.

Coronary arteries form the network of blood vessels on the surface of the heart thatfeeds it oxygen. If these arteries narrow, the heart may not receive enoughoxygen-rich blood, especially during physical activity.

CAD can sometimes lead to a heart attack. According to the Centers for DiseaseControl and Prevention, it is the most common type of heart diseaseTrusted Source inthe United States, where it accounts for more than 655,000 deathsTrusted Sourceevery year.

CAD is caused by plaque buildup in the walls of the arteries that supply blood to theheart (called coronary arteries) and other parts of the body.Plaque is made up ofdeposits of cholesterol and other substances in the artery. Plaque buildup causesthe inside of the arteries to narrow over time, which can partially or totally blockthe blood flow. This process is called atherosclerosis.

If pieces of plaque break off or rupture, platelets will cluster in the area in anattempt to repair the blood vessel. This cluster can block the artery and reduce orblock blood flow, which may lead to a heart attack.

You may not know you have coronary artery disease since you may not have symptoms atfirst. The buildup of plaque in your arteries takes years to decades. But as yourarteries narrow, you may notice mild symptoms that indicate your heart is pumpingharder to deliver oxygen-rich blood to your body. The most common symptoms are chestpain or shortness of breath, especially after light physical activity like walkingup stairs, but even at rest.

Sometimes you won’t know you have coronary artery disease until you have a heartattack. Symptoms of a heart attack include:

1. Chest discomfort (angina) described as heaviness, tightness, pressure, aching,burning, numbness, fullness, squeezing or a dull ache. The discomfort can alsospread to or only be felt in your left shoulder, arms, neck, back or jaw.

2. Feeling tired.

3. Dizziness, lightheadedness.

4. Nausea.

5. Weakness.

Symptoms of a heart attack in women can be slightly different and include:

1. Discomfort or pain in the shoulders, neck, abdomen (belly) and/or back.

2. Feeling of indigestion or heartburn.

3. Unexplained anxiety.

4. Cold sweat.

Because the symptoms of coronary artery disease can be symptoms of a heart attack,you need to seek immediate help. Call 911 if you think you are having symptoms of aheart attack.

If a blood clot in a coronary artery has broken loose and moved into your brain, itcan cause a stroke, although this is rare. Symptoms of a stroke include:

1. Drooping on one side of your face. Look at your smile in a mirror or ask someoneto check your smile.

2. Arm weakness or numbness.

3.Difficulty speaking/slurred speech.

If you experience any of these symptoms, call 911. Every minute you spend withouttreatment increases your risk of long-term damage.

First, unless your condition is an emergency (you’re having a heart attack orstroke), your cardiologist (heart doctor) will ask you about your symptoms, takeyour medical history, review your risk factors and perform a physical exam.

Diagnostic tests may include:

1. Electrocardiograph tests (EKG): This test records the electrical activity of theheart. Can detect heart attack, ischemia and heart rhythm issues.

2. Cardiac catheterization: This test involves inserting small tubes into the bloodvessels of the heart to evaluate heart function including the presence of coronaryartery disease.

3. Exercise stress tests: This is a treadmill test to determine how well your heartfunctions when it’s working the hardest. Can detect angina and coronary blockages.

4. Pharmacologic stress test: Instead of using exercise to test your heart when it isworking its hardest, medication is given to increase your heart rate and mimicexercise. This test can detect angina and coronary blockages.

5. Echocardiogram: This test uses sound waves to see how well the structures of yourheart are working and the overall function of your heart.

6. Coronary calcium scan: This test measures the amount of calcium in the walls ofyour coronary arteries, which can be a sign of atherosclerosis.

7. Blood tests: Many blood tests are ordered for factors that affect arteries, suchas triglycerides, cholesterol, lipoprotein, C-reactive protein, glucose, HbA1c (ameasure of diabetes control) and other tests.

Other diagnostic imaging tests may include:

Nuclear imaging: This test produces images of the heart after administering aradioactive tracer.

Computed tomography angiogram: Uses CT and contrast dye to view 3D pictures of themoving heart and detect blockages in the coronary arteries.

Your healthcare provider will talk to you about the best treatment plan for you.Follow your treatment plan to reduce your risk of problems that can result fromcoronary artery disease, like heart attack and stroke.

Lifestyle changes

The first step in treating coronary artery disease is to reduce your risk factors.This involves making changes in your lifestyle.

1. Don’t smoke. If you smoke or use tobacco products, quit. Ask your healthcareproviders about ways to quit, including programs and medications.

2. Manage health problems like high cholesterol, high blood pressure and diabetes.

3. Eat a heart-healthy diet. Talk to your healthcare provider or a registereddietitian about ways to change your diet to reduce your risk of heart disease. Gooddietary choices include the Mediterranean and DASH diets.

4. Limit alcohol use. Limit daily drinks to no more than one drink per day for womenand two drinks per day for men.

5. Increase your activity level. Exercise helps you lose weight, improve yourphysical condition and relieve stress. Most people can reduce their risk of heartattack by doing 30 minutes of walking five times per week or walking 10,000 stepsper day. Talk to your healthcare provider before you start any exercise program.

Medications

Your healthcare provider will recommend medications to best manage your risk factorsfor heart disease. Types of heart-related medications that may be selected for youinclude:

1. Medication to lower your cholesterol levels, such as statins, bile acidsequestrants, niacin and fibrates.

2. Medications to lower blood pressure, such as beta blockers, calcium channelblockers, angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptorblockers.

3. Medications to stop angina, such as nitrates/nitroglycerin or ranolazine.

4. Medications to reduce the risk of blood clots, such as anticoagulants (includingaspirin) and antiplatelets.

If you have diabetes and coronary artery disease, you’ll be prescribed medications tolower your blood sugar level.

It's important to take all medications as prescribed, including those for heartdisease and all other health conditions. Talk to your healthcare provider if youhave any questions or concerns about which medications to take or how to take them.

Procedures and surgery

Interventional procedures are nonsurgical treatments to get rid of plaque buildup inthe arteries and prevent blockages. Common procedures are balloon angioplasty andstenting. These procedures are done with a long, thin tube called a catheter. It isinserted into an artery in the wrist or the top of the leg through a small incisionand guided to the blocked or narrowed area of the artery. The balloon widens thediameter of the artery to restore blood flow to the heart. A stent (a small metalspring-like scaffold) is left in place to keep your artery open.

Coronary artery bypass graft (CABG) surgery involves creating a new path for blood toflow when there is a blockage in the coronary arteries. In most cases, the surgeonremoves blood vessels from your chest, arm or leg, and creates a new pathway todeliver oxygen-rich blood to the heart.

If traditional treatment options are not successful, your cardiologist may recommendother treatment options, such as enhanced external counterpulsation (EECP). In thisprocedure, inflatable cuffs (like blood pressure cuffs) are used to squeeze theblood vessels in your lower body. This helps improve blood flow to the heart andhelps create natural bypasses (collateral circulation) around blocked coronaryarteries. Enhanced external counterpulsation is a possible treatment for those withchronic stable angina who can’t have an invasive procedure or bypass surgery anddon't get relief from medication.

Coronary artery disease is caused by atherosclerosis. Atherosclerosis is the buildupof plaque inside your arteries. Plaque consists of cholesterol, fatty substances,waste products, calcium and the clot-making substance fibrin. As plaque continues tocollect on your artery walls, your arteries narrow and stiffen. Plaque can clog ordamage your arteries, which limits or stops blood flow to your heart muscle. If yourheart does not get enough blood, it can't get the oxygen and nutrients it needs towork properly. This condition is called ischemia. Not getting enough blood supply toyour heart muscle can lead to chest discomfort or chest pain (called angina). Italso puts you at risk for a heart attack.

Coronary artery disease happens in everyone. The speed at which it develops differsfrom person to person. The process usually starts when you are very young. Beforeyour teen years, the blood vessel walls start to show streaks of fat. As plaquedeposits in your artery’s inner walls, your body fights back against this ongoingprocess by sending white blood cells to attack the cholesterol, but the attackcauses more inflammation. This triggers yet other cells in the artery wall to form asoft cap over the plaque.This thin cap over the plaque can break open (due to bloodpressure or other causes). Blood cell fragments called platelets stick to the siteof “the injury,” causing a clot to form. The clot further narrows arteries.Sometimes a blood clot breaks apart on its own. Other times the clot blocks bloodflow through the artery, depriving the heart of oxygen and causing a heart attack.

Heart attack.

Angina

Heart rhythm problems.

Heart failure.

Cardiogenic shock.

Cardiogenic shock.

Sudden cardiac arrest.

You can reduce your chance of developing these heart conditions if you follow yourcardiologist’s treatment plan.

You can certainly make changes that will lower your chance of developing coronaryartery disease, but this condition is not 100% preventable. This is because thereare two kinds of risk factors: Those that can’t be changed (nonmodifiable) and thosethat can be (modifiable).

Nonmodifiable risk factors include older age, male gender, a family history of heartdisease and genetic factors. See the question, “who gets coronary artery disease”earlier in this article for more information.

However, there are many risk factors that you can modify. These are mostly lifestylechanges like losing weight if you’re overweight, stopping smoking if you smoke,keeping your blood pressure and cholesterol level at their goal numbers and managingdiabetes. See “lifestyle changes” under the treatment section of this article formore examples.

Keep in mind that the more risk factors you have, the higher the chance of havingheart disease. Fortunately, you can choose to help yourself and reduce the risk ofdisease by taking control over your risk factors that can be changed.

Coronary artery disease happens in everyone. The speed at which it develops differsfrom person to person. The process usually starts when you are very young. Beforeyour teen years, the blood vessel walls start to show streaks of fat. As plaquedeposits in your artery’s inner walls, your body fights back against this ongoingprocess by sending white blood cells to attack the cholesterol, but the attackcauses more inflammation. This triggers yet other cells in the artery wall to form asoft cap over the plaque.This thin cap over the plaque can break open (due to bloodpressure or other causes). Blood cell fragments called platelets stick to the siteof “the injury,” causing a clot to form. The clot further narrows arteries.Sometimes a blood clot breaks apart on its own. Other times the clot blocks bloodflow through the artery, depriving the heart of oxygen and causing a heart attack.

You have an increased risk of coronary artery disease if you:

1. Have a high cholesterol level (especially a high LDL “bad” cholesterol level and alow HDL “good” cholesterol level).

2. Have high blood pressure.

3. Family history of heart disease.

4. Have diabetes.

5. Are a smoker.

6. Are a man over 45 years of age or a post-menopausal woman.

7. Are overweight.

8. Are physically inactive.

If you have these risk factors, talk with your healthcare provider. They may want totest you for coronary artery disease.