What Is Coronary Artery Disease and How Does It Develop?

Coronary Artery Disease (CAD), also known as atherosclerosis, is a condition in which the arteries that supply blood to the heart muscle (myocardium) become narrow due to plaque buildup. Lack of oxygen-rich blood to the heart muscle may result in chest pain, shortness of breath, a heart attack or permanent heart damage.

According to Mayo Clinic, CAD develops slowly over many years, often without symptoms. Plaque accumulation can be accelerated by factors such as high levels of cholesterol, high blood pressure, inflammation, smoking, diabetes, and genetics.

Impact of  Coronary Artery Disease

The American Heart Association (AHA) cites coronary artery disease as the most prevalent form of heart disease in the world. It occurs when plaque made of cholesterol, fats, calcium, and inflammatory cells accumulates inside the coronary arteries.

Over time, this plaque blocks the arteries and reduces blood circulation. Once a fragment of plaque tears, it may create a blood clot, which will completely block the artery, which is a major reason for heart attacks.

Step-by-Step Guide on How CAD Develops

CAD progresses gradually. Many people have initial atherosclerosis (chronic narrowing and hardening of the arteries due to plaque buildup) without knowing it. Here’s how CAD progresses stage by stage: 

1. Endothelial Damage (The First Event)

The inner lining of the arteries is called the endothelium. High blood pressure, smoking, diabetes, and inflammation can damage it. Once damaged, LDL or bad cholesterol slips into the artery wall.

Some common causes of endothelial injury:

• High LDL cholesterol
• High blood pressure
• Smoking or second-hand smoke
• Diabetes or resistance to insulin
• Chronic inflammation
• High-sugar, high-fat diet
• Sedentary habits
• Stress and poor sleep quality

2. Fatty Streak Formation

Immune cells rush to the site to clean up LDL particles, creating a fatty streak. According to a study published in the journal Cholesterol, this is one of the earliest visible signs of CAD. Dr Utagi notes that these streaks can be observed in adolescents.

3. Plaque Growth

With the increasing fat, cholesterol, and inflammatory cell build-up, plaque begins to form and harden. As a result, the arteries (arterial calcification) further become stiff because of calcium deposits.

4. Narrowing of Arteries

When plaques get large, arteries get narrowed and limit blood flow. “The symptoms can begin to manifest themselves during physical activity or when one is under emotional pressure,” Dr Utagi points out.

5. Plaque Rupture/ Clot Formation

The most hazardous stage is the cracking of the plaque. The body forms a clot to seal the rupture, but this clot can block the artery completely. This triggers:

• Myocardial infarction (heart attack)
• Unstable angina
• Sudden cardiac arrest

Symptoms of Coronary Artery Disease

As per the Cleveland Clinic, some people experience no symptoms until CAD is advanced. Women, in particular, may get subtle symptoms such as indigestion-like discomfort, back pain, or unusual fatigue. However, the most common symptoms include:

• Chest pain or pressure (angina)
• Pain in the arm, shoulder, neck, jaw, or back
• Shortness of breath
• Fatigue
• Nausea or cold sweats
• Dizziness
• Palpitations

Risk Factors: What Increases Your Chances of CAD?

Coronary artery disease risk factors include both modifiable and non-modifiable aspects, including:

1. Modifiable Risk Factors

The following factors can be improved with lifestyle changes and treatment:

• High LDL cholesterol
• Low HDL cholesterol
• High blood pressure
• Smoking or vaping
• Diabetes
• Obesity (belly fat in particular)
• Lack of physical activity
• A diet rich in saturated fats and sugar
• High stress
• Chronic inflammatory diseases

2. Non-Modifiable Risk Factors

On the other hand, the following non-modifiable risk factors cannot be changed:

• Age
• Early heart disease family history
• Genetics (e.g., familial hypercholesterolemia)
• Gender (higher early risk in men)

Complications of Coronary Artery Disease

According to StatPearls, a comprehensive, peer-reviewed, online medical library of clinical review articles, if untreated, CAD can lead to:

• Heart attack
• Arrhythmias
• Heart failure
• Reduced exercise capacity
• Sudden cardiac death

How CAD Is Diagnosed

Diagnosing coronary heart disease depends on your symptoms, risk factors, personal and family medical history, and heart test results. Your doctor will likely screen you during routine checkups and can even use specialised tools to calculate your 10-year risk of developing the condition. 

Dr Utagi explains that a medical practitioner can prescribe:

• Blood analyses (cholesterol, blood sugar, inflammatory indicators)
• Electrocardiogram (ECG)
• Stress test
• Echocardiogram
• Coronary CT angiography
• Cardiac catheterisation

Can CAD Be Prevented or Slowed Down?

Yes. According to a 2019 study conducted at Harvard, lifestyle modification and treatment can slow down the progression of CAD and even stabilise plaque.

Here is the ultimate prevention and management strategy, as per Dr Utagi:

• Lower LDL cholesterol (diet and medication when needed)
• Exercise regularly (150 minutes per week)
• Quit smoking
• Manage blood pressure
• Control blood sugar
• Improve sleep quality
• Reduce stress
• Eat a heart-healthy (Mediterranean or DASH) diet.

Treatment for Coronary Heart Disease

The treatment depends on the person and must be provided by a cardiologist. Medical interventions could involve:

• Statins
• Beta-blockers
• Antiplatelets
• ACE inhibitors
• Angioplasty and stenting
• Bypass surgery

Difference Between CAD and Heart Attack

Coronary Artery Disease (CAD) is an underlying chronic condition where plaque buildup narrows the heart's arteries over time. On the other hand, a heart attack or myocardial infarction is an acute, life-threatening event caused when that plaque ruptures, blocking blood flow entirely. In simpler terms, CAD is the cause, whereas a heart attack is a potential result of it.

When Should You See a Doctor?

Dr Utagi warns that certain symptoms can be the signs of a heart attack. Seek urgent medical attention in case of:

• Chest pain lasting more than a few minutes
• Pain that spreads to the arm, jaw, or back
• Sudden breathlessness
• Unexplained nausea or sweating
• Dizziness or fainting

Bottomline

Coronary artery disease develops gradually when plaque builds up in the arteries that supply the heart. Although CAD often progresses silently for years, early detection and preventive care can significantly reduce the risk of heart attacks and long-term heart damage.

[Disclaimer: This article should be considered purely informational and should not be used in place of professional medical advice. Always consult a healthcare provider for diagnosis and treatment.]