Have you ever wondered what leads to coronary heart disease (CHD)? If so, you are reading the right article. CHD is a widespread health issue that affects people all over the world, but by knowing its stages and how it progresses, you can work to stop or deal with it well. This article will outline the stages of CHD and what causes it so that you can be aware of how to prevent it.

Introduction

The coronary arteries deliver blood to the heart muscles. This blood is rich with oxygen, which the heart needs to function well. The coronary arteries are located on the surface of the heart and have many small branches that, together, supply blood to all of the heart’s cells. The importance of these arteries cannot be understated - a lack of supply of oxygen-rich blood to the heart can cause it to not function properly. Coronary heart disease (CHD), also known as coronary artery disease (CAD), is a condition caused by inflammation and the build-up of fatty deposits (plaque) within the coronary arteries. These plaques can start to form in life and develop over time without you knowing. Eventually, the plaques cause the arteries to narrow - reducing, or outright blocking, blood flow to the heart. This is known as atherosclerosis.¹

What are the symptoms of coronary artery disease?

The symptoms of CAD may vary from person to person, depending on their condition.¹ Some common symptoms include:

• Angina (chest pain)
• Feeling sick (nausea)
• Feeling tired/ weak
• Pain throughout the body
• Shortness of breath²

However, some people may not have any symptoms. If blood (and oxygen) flow is partially restricted, you may experience mild angina. If blood flow (and oxygen supply)  completely stops, you may experience a heart attack as the heart muscle will begin to die.¹ Therefore, you must seek medical attention if you have experienced these symptoms.

Stages of coronary heart disease

CHD progresses gradually over time. By understanding the different stages of the disease, you can take steps early on to slow or even stop its development.

Stage 1 - initial damage to artery walls

CHD is initiated by damage to the coronary artery walls. Many factors can increase the risk of this damage occurring. These are known as risk factors and include:³

• Age: in individuals assigned male at birth (AMAB), the risk for CHD begins to increase around the age of 45 and in individuals assigned female at birth (AFAB), the risk begins to rise from the age of 55. For individuals With FAB, this has been linked to hormonal changes caused by menopause. However, arterial plaques also build up as we age - further increasing our risk of developing CHD as we age
• Environmental factors: living in places with higher air pollution increases your risk of CHD. Air pollution can also worsen other conditions, such as high blood pressure and inflammation, which contribute to the development of CHD. Exposure to toxins, radiation, stress, sitting for long periods, and working for long periods without enough or regular sleep also increase the risk of CHD
• Family history and genetics: if you have a family member that has or had CHD, the risk of you developing CHD is increased. This is because there has been research to show that families can pass on through certain genes
• Lifestyle habits: unhealthy habits can increase the risk of plaque formation in the arteries. These include eating foods with high saturated fats and refined carbohydrates, which could lead to obesity and an increase in bad cholesterol in the blood. Being physically inactive can also have the same effect. Smoking can damage the arteries directly. Regular, healthy sleep reduces the stress on your heart as it gives it the time it needs to slow down and recover. Without this, it may increase blood pressure and lead to symptoms of CHD

With age and sex being factors we cannot control, knowing what changes you can make in your daily life can be instrumental in stopping the progression of the condition. Simple changes to our eating habits are recommended to reduce the risk of CHD.³

Stage 2 - plaque formation (atherosclerosis)

Damage to the inner lining of arteries triggers an immune response - causing white blood cells to travel to the site of injury and cause the area to become inflamed. A type of white blood cell known as foam cells continues to build up at this site, consuming cholesterol to try to get rid of it. These cells die here, contributing to the formation of fatty deposits alongside other molecules. These deposits can cause further damage to the artery walls.

Eventually, a fibrous cap (made from muscle cells) forms a hard layer on the top of the plaque, preventing it from breaking off. Eventually, this process narrows the coronary artery, reducing blood flow. Over time, this may get worse, further narrowing the arteries. This formation of plaque within the arteries is known as atherosclerosis.⁴

Stage 3 - coronary artery blockage

Atherosclerosis is very common. It forms gradually, meaning that people may not show any symptoms until the condition has already advanced significantly. However, the long-term narrowing of the arteries and reduced blood flow to the heart may lead to angina (chest pain). This is a typical warning sign that you could be at risk of a heart attack or other serious complications. There are two main types of angina which affect the way you manage your symptoms: stable and unstable angina. Stable angina is more common. It is triggered by stress or physical exercise and will stop once stress reduces. Unstable angina tends to cause more serious attacks, which may not have a trigger.⁵

As the arteries continue to narrow, the plaque may rupture, creating a blood clot. A blood clot may completely prevent blood from following to the heart, resulting in heart attacks.⁴

Stage 4 - myocardial infarction (heart attack)

A heart attack - also known as a myocardial infarction - is a very serious medical emergency. It is caused by a sudden stop in the heart’s blood supply. When the blood supply is stopped, the heart no longer receives oxygen, and the heart tissue begins to die. Symptoms of a heart attack include angina, pain in other parts of the body, dizziness, nausea, coughing, sweating and/or shortness of breath. However, these symptoms may vary from person to person. It is important to note that angina may not always be severe (it has been compared to pain from indigestion). Seeking medical attention significantly improves the chances of a successful recovery.⁶

Stage 5 - heart failure

After a heart attack, the heart becomes weaker and may need help pumping blood. This is known as heart failure. Common symptoms of heart failure are shortness of breath and swelling of the lower body. Options for treatment are lifestyle changes, such as regular exercise, surgical implants like a pacemaker, and medication to regulate normal heart rhythm.⁷

Summary

Coronary heart disease (CHD), also called coronary artery disease (CAD), happens when the coronary arteries become inflamed and clogged with fatty deposits, known as plaque. CHD is a slow-progressing disease as it involves plaque formation, which occurs over time. As such, it may take years to reach this critical point. Arterial plaque formation causes the coronary artery to narrow, reducing blood flow to the heart, and resulting in the heart getting less oxygen. Complete blockages of blood flow may cause a heart attack. 

Understanding the stages of coronary heart disease and the risk factors affecting its development can help you take control of your heart health. Whether you want to prevent CHD or manage an existing condition, there are many steps you can take, such as implementing a healthier lifestyle, reducing stress levels and improving sleeping patterns. This is especially important for those at a higher risk of developing CHD, such as the elderly, those with CHD running in the family, and people with obesity.