Coronary Artery Disease

What is coronary artery disease

Coronary artery disease (CAD) is a narrowing or blockage of your coronary arteries, commonly due to plaque buildup. Your coronary arteries carry oxygen-rich blood to your heart. Plaque buildup in these arteries reduces how much blood can reach your heart.

Imagine two traffic lanes that meld into one due to construction. Traffic keeps flowing, just slower. With CAD, you might not detect anything wrong until the plaque triggers a blood clot. The blood clot is like a concrete blockade in the middle of the road - traffic stops. Correspondingly, blood can’t reach your heart, and this leads to a heart attack.

You may have CAD for many years and not have any symptoms until you suffer a heart attack. That’s why CAD is commonly called - a “silent killer.”

Alternative names for CAD are coronary heart disease (CHD) and ischemic heart disease. It’s also what most people intend when they use the common term “heart disease.”

Forms of coronary artery disease:

There are two major forms of coronary artery disease:

Stable ischemic heart disease - this is the chronic type. Your coronary arteries progressively narrow over the years. Over time, your heart gets less oxygen-rich blood. You may feel a few symptoms, but you’re able to live with the condition daily.

Acute coronary syndrome - this is the unforeseen form that’s a medical emergency. The plaque in your coronary artery unexpectedly ruptures and forms a blood clot that blocks blood flow to your heart. This abrupt obstruction causes a heart attack.¹

Symptoms, causes and treatment

Symptoms of coronary artery disease

You may have no symptoms of coronary artery disease for a long time - CAD is a chronic disease. Plaque buildup takes many years, even decades. However, as your arteries narrow, you may notice moderate symptoms. These symptoms display your heart is pumping harder to deliver oxygen-rich blood to your whole body.

Symptoms of chronic CAD include:

• Stable angina - the most common symptom. Stable angina is a temporary chest pain or discomfort that comes and goes in a certain pattern. You’ll normally notice it during physical activity or emotional anguish. It goes away when you rest or take nitroglycerin, which is a medicine that treats angina
• Shortness of breath (dyspnea) - some people feel short of breath amid light physical activity

Occasionally, the first manifestation of CAD is a heart attack. 

Symptoms of a heart attack contain:

• Chest pain or discomfort (angina). Angina can differ from mild discomfort to severe pain. It may feel like tightness, pressure, heaviness, aching, burning, fullness, numbness, squeezing or a dull ache. The discomfort may spread to your shoulder, neck, arm, jaw or back
• Shortness of breath or trouble breathing
• Feeling dizzy or lightheaded
• Feeling tired
• Heart palpitations
• Nausea, stomach discomfort or vomiting
• Weakness

Women are more likely to have extra, atypical symptoms that contain:

• Fatigue, shortness of breath, and insomnia that began before the heart attack
• Pain in their back, arms, shoulders, neck or belly
• Heart racing
• Feeling hot or flushed¹

Causes of coronary artery disease

Coronary artery disease starts when cholesterols, fats and other substances accumulate on the inner walls of the heart arteries. This condition is called atherosclerosis and the buildup is called plaque. Plaque can cause the arteries to narrow, therefore blocking the blood flow. The plaque can also erupt, leading to a blood clot.

Aside from high cholesterol, damage to the coronary arteries may be caused by:

• Diabetes or insulin resistance
• High blood pressure
• Not getting enough exercise (sedentary lifestyle)
• Smoking or tobacco use³

Coronary artery disease treatment

Coronary heart disease cannot be cured but treatment can help maintain the symptoms and minimize the chances of problems such as heart attacks.

Treatment can include:

• lifestyle changes, such as stopping smoking and regular exercise
• Drugs
• Angioplasty, where balloons and stents are used to deal with narrow heart arteries
• surgery²

Diagnosis and prevention

How is coronary artery disease diagnosed

Healthcare professionals diagnose coronary artery disease with a physical exam and testing.

During your physical exam, your doctor will:

• Measure your blood pressure
• Listen to your heart with a stethoscope
• Ask what symptoms you’re encountering and how long you’ve had them
• Ask you about your medical history
• Ask you about your lifestyle
• Ask you about your family history. They’ll want to know about heart disease among your biological parents and siblings

All of this information will help the healthcare professional to determine your risk for heart disease.

Tests that help diagnose coronary artery disease

Your doctor may additionally advise one or more tests to assess your heart function and diagnose CAD. These contain:

• Blood tests - Check for elements that harm your arteries or increase your risk of CAD
• Cardiac catheterization - Inserts tubes into your coronary arteries to assess or confirm CAD. This test is the gold standard for diagnosing CAD
• Computed tomography (CT) coronary angiogram - Uses CT and contrast dye to view 3D images of your heart as it moves. Detects blockages in your coronary arteries
• Coronary calcium scan - Calculates the amount of calcium in the walls of your coronary arteries (a sign of atherosclerosis). This doesn’t conclude if you have significant blockages, but it does help determine your risk for CAD
• Echocardiogram (echo) - Uses sound waves to assess your heart’s structure and function
• Electrocardiogram (EKG/ECG) - Records your heart’s electrical activity. Can detect old or current heart attacks, ischemia and heart rhythm problems
• Exercise stress test - Checks how your heart responds when it’s working very hard. Can detect angina and blockages in your coronary arteries¹

How can we prevent coronary artery disease

It is not possible to always prevent coronary artery disease. That’s due to some risk factors that are out of our control. However, there’s a lot you can do to lower your risk of CAD. Many approaches to lower your risk can also help maintain your condition once you’re diagnosed.

You can lower your risk of CAD and help prevent it from getting worse by doing the following:

• Commit to quitting smoking and all tobacco usage
• Eat a heart-healthy diet - avoiding foods high in saturated fat, trans fat, sugar and sodium. It also means restricting the intake of refined carbohydrates (like pasta and white bread). You can replace such foods with whole grains (like brown rice and wheat bread ). It’s also vital to learn how nutrition affects your cholesterol levels
• Get enough sleep - most adults require seven to nine hours of quality sleep per night. However many people might find this target difficult, if not quite impossible. Work schedules, parenting and other responsibilities may prevent you from getting enough rest. Talk with your doctor about strategies for getting the quality sleep you need to support your heart health
• Keep a healthy weight -talk with your doctor about what your ideal weight should be. Work with your doctor to set manageable targets until you reach your ideal weight. Refrain from short-term diets that are very restrictive
• Learn your risk for heart disease - visit your doctor for a risk screening starting at age 20. Your doctor will take some basic measurements, like your blood pressure and BMI
• Limit alcohol use - excess alcohol intake can harm your heart. Men should drink no more than two drinks per day and women should restrict their intake to one drink per day. However, drinking less is even better
• Move around more - it’s important to try to exercise for 150 minutes per week (ie. 30 minutes walks five days a week). Ultimately, the more you move, the better for your heart. Of course, check with your doctor about what level of activity is safe for you
• Intake recommended medications - medications are vital in decreasing your risk for CAD and preventing heart attacks if you’ve already been diagnosed with CAD. Many of these medications are prescribed lifelong. It’s important to understand what they do and how they prevent events and even prolong your life¹

Risk factors

Coronary artery disease is a common condition. Genetics, age, other health conditions and lifestyle preferences can affect the health of the heart arteries.

Coronary artery disease risk factors contain:

• Age - getting older increases the risk of narrowed and damaged arteries
• Sex - men are usually at greater risk of coronary artery disease. However, the risk for women grows after menopause
• Family history - a family history of heart disease makes you more prone to get CAD. This is particularly true if a close relative (parent, sibling) developed heart disease at an early age
• Smoking - if you smoke, do yourself a favour and quit. Smoking is bad for heart health. People who smoke have a significantly raised risk of heart disease
• High blood pressure - unchecked high blood pressure can make arteries stiff and hard (arterial stiffness). The coronary arteries may become narrow, slowing the blood flow
• High cholesterol - too much bad cholesterol in the blood can raise the risk of atherosclerosis. Bad cholesterol is named low-density lipoprotein (LDL) cholesterol. Not enough good cholesterol, which is named high-density lipoprotein (HDL) - also leads to atherosclerosis
• Diabetes - diabetes raises the risk of coronary artery disease. Type 2 diabetes and coronary artery disease share some risk factors, such as high blood pressure and obesity
• Overweight or obesity - excess body weight is bad for overall health. Obesity can cause type 2 diabetes and high blood pressure. Ask your doctor what a healthy weight is for you
• Chronic kidney disease - having long-term kidney disease increases the risk of CAD
• Not getting enough exercise - physical activity is essential for good health. A lack of exercise is linked to coronary artery disease and some of its risk factors
• A lot of stress - emotional stress may harm the arteries and worsen other risk factors for coronary artery disease
• Unhealthy diet - eating foods with a lot of saturated fat, trans fat, sugar and salt can increase the risk of coronary artery disease
• Alcohol use - heavy alcohol use can cause heart muscle damage. It can also worsen other risk factors of CAD
• Amount of sleep - too little and too much sleep have both been connected to an increased risk of heart disease

Risk factors often transpire together, one risk factor may trigger another.

When grouped, specific risk factors make you even more likely to develop CAD. For example, metabolic syndrome, which is a bundle of conditions that contain high blood sugar,  high blood pressure, excess body fat around the waist and high triglyceride levels - raises the risk of CAD.

Sometimes coronary artery disease progresses without any common risk factors. Other possible risk factors for CAD may contain:

• Breathing pauses during sleep (obstructive sleep apnea). This condition causes breathing to stop and start while sleeping. It can cause a sudden decline in blood oxygen levels. The heart must work harder, therefore blood pressure goes up
• High-sensitivity C-reactive protein (hs-CRP). This protein occurs in higher-than-usual quantities when there's inflammation somewhere in the body. High hs-CRP levels may be a risk factor for heart conditions. It's understood that as coronary arteries narrow, the level of hs-CRP in the blood goes up
• High triglycerides - it is a type of lipid (fat) in the blood. High levels may raise the risk of CAD, especially for women
• Homocysteine - it is an amino acid the body uses to create protein and to build and maintain tissue.  However, high levels of homocysteine may raise the risk of coronary artery disease
• Preeclampsia - this pregnancy complication causes high blood pressure and raised protein in the urine. It can cause a higher risk of heart disease later in life
• Other pregnancy complications  - diabetes or high blood pressure during pregnancy are also known risk factors for CAD
• Certain autoimmune diseases - people who have conditions such as rheumatoid arthritis and lupus, or any other inflammatory conditions, have a raised risk of atherosclerosis³

When to see a doctor

Smoking or having high blood pressure, obesity, diabetes, high cholesterol or a strong family history of heart disease makes you more likely to develop coronary artery disease. If you're at high risk of CAD, talk to your healthcare provider. You may need to do some tests to check for narrowed arteries and CAD.³

Summary

Learning you have coronary artery disease can cause a lot of mixed emotions. You may feel confused about how this could happen. You may feel upset or wish you’d done some things differently to prevent this diagnosis. Let go of any guilt or disappointment you feel. Alternatively, commit to building a plan to help your heart, starting today.

Work with your doctor to embrace lifestyle changes that feel manageable to you. Learn about treatment opportunities, including medications, and how they support your heart health. Tell your family and friends about your objectives and how they can help you. This is your journey, but you don’t have to and you shouldn’t do it alone.¹