What Causes Coronary Artery Disease (CAD)?

Coronary artery disease (CAD) occurs when the arteries (heart's blood vessels) become too narrow, making it difficult for blood to flow in and out of the heart.

The most common cause of CAD is a heart condition called atherosclerosis, or the buildup of cholesterol plaque in arteries. Over time, the plaque can restrict blood flow to the heart, cause blood clots to form, and raise the risk of a heart attack.

Who Gets CAD?

Anyone can develop coronary artery disease, but certain factors can increase the risk:

• Age: Older adults have a higher risk of developing CAD
• Sex: Males over 45 and females over 55 are more likely to develop the condition
• Ethnicity: CAD can affect any ethnic background but tends to be more common among white people (11.5%), Black people (9.5%), Hispanic people (7.4%), and Asian people (6.0%)
  

Is Coronary Artery Disease Hereditary?

People who have a family history of coronary artery disease have a higher risk of developing the condition themselves, indicating that there is a genetic component to this disease. Specific genetic conditions that are strongly tied to an increased risk of CAD include familial hypercholesterolemia (FH):

Familial Hypercholesterolemia (FH)

Familial hypercholesterolemia occurs due to a mutation in the LDL receptor that leads to very high levels of low-density lipoprotein (LDL) cholesterol. LDL cholesterol is often known as "bad cholesterol" because of its association with atherosclerosis and heart disease.

FH is autosomal dominant, meaning you only need one copy of the genetic mutation from one of your parents to develop the condition. Those with two copies have higher LDL cholesterol and a higher risk of developing CAD at a younger age.

Lipoprotein(a), or Lp(a)

Lipoprotein(a) is a type of fat in your blood that mimics the structure of LDL cholesterol. Elevated levels of Lp(a) can increase your risk of CAD. Researchers believe that your genetics determine 70-90% of this protein.

Risk Factors

Underlying health conditions, lifestyle habits, and environmental factors can increase your likelihood of developing coronary artery disease.

High Cholesterol

High cholesterol increases your CAD risk. Various lipoproteins (lipid-protein particles) carry cholesterol in the body. A lipid profile blood test can provide information about specific lipoproteins.

Dyslipidemia (abnormal lipid levels in the blood) can take many forms, and the following cholesterol levels are specifically tied to CAD risk:

• High low-density lipoprotein (LDL) cholesterol: Also known as "bad cholesterol," high levels of LDL can increase your risk of CAD and other heart-related complications like heart attack and stroke.
• Low high-density lipoprotein (HDL) cholesterol: Otherwise known as "good cholesterol," too little HDL can also increase your risk of heart disease.
• High triglycerides: These molecules are the most common type of fat in your body, and excess triglycerides in the blood can raise CAD risk.

High Blood Pressure

High blood pressure is a common condition that affects nearly half of all adults in the United States. It's also a strong risk factor for coronary artery disease and other cardiovascular disease.

Normal blood pressure is less than 120/80 millimeters of mercury (mmHg), and elevated numbers can raise your risk of high blood pressure. Keeping your blood pressure under control through diet, exercise, and medications can help lower your risk of heart disease.

Diabetes

Diabetes occurs when you have elevated blood sugar levels. This excess sugar can affect your heart and blood vessels.

Researchers estimate that diabetes nearly doubles your risk of heart disease, and it can also raise your chances of developing other CAD risk factors, such as high blood pressure and high cholesterol. If you receive a diagnosis of diabetes, keep your blood sugar levels in a normal range through lifestyle habits and medications to prevent this.

Lifestyle Factors

Lifestyle factors can also raise your chances of experiencing CAD. You may be at increased risk if you:

• Smoke tobacco or vape
• Inhale secondhand smoke from someone else's cigarettes
• Live a sedentary lifestyle by not getting enough physical activity in your daily routine
• Eat a diet that is high in sodium, trans fats, refined sugars, and processed foods
• Drink excess alcohol
• Experience chronic stress and don't use healthy coping mechanisms to reduce it

These risk factors are considered "modifiable," meaning you have control over changing them.

For example, if you're not exercising enough, consider incorporating more physical activity by going on a daily walk or practicing yoga. If you use alcohol or tobacco frequently, talk to your healthcare provider about cessation programs or support groups that can help you reduce your intake.

Environmental Factors

Certain environmental factors can also increase your risk of heart disease, among other health conditions. Researchers found that the most common environmental exposures associated with CAD include:

• Air pollution
• Noise exposure
• Nighttime light pollution
• Chemical pollutants like PFAS
• Climate change
  

A Quick Review

Coronary artery disease is the most common type of heart disease, and it occurs when your heart's arteries narrow, causing difficulties in blood flow. CAD occurs due to atherosclerosis, a term for plaque buildup in the arteries.

Several factors can raise your risk of atherosclerosis and, thereby, CAD. These include older age, high blood pressure, smoking, chronic stress, and climate change. Some of these risks are modifiable, so healthy lifestyle changes can help reduce your CAD risk.