Introduction to Coronary Heart Disease (CHD)

Definition and Overview

Coronary arteries are branches of the body’s main artery, the Aorta. They supply blood to the heart.  Due to plaque deposition, the arteries narrow down and the oxygen-rich blood flow to the heart is reduced. This results in shortness of breath, pain, and discomfort in the chest.

In this article, we’ll go through various risk factors associated with Coronary Heart Disease (CHD), causes of  CHD, ways to manage them, and treatment options. 

Prevalence 

Coronary Heart Disease (CHD) or Coronary Artery Disease (CAD) is the most common type of heart disease worldwide.

According to the Journal of American College of Cardiology (JACC), about 315 million cases of CHD were reported globally in 2022. The highest number of cases were seen in Central Europe, Eastern Europe, and Central Asia. The lowest number of cases was seen in South Asia.¹

Unhealthy diet and lifestyle, higher smoking rates, higher stress, and limited access to preventive healthcare are major contributing factors to the huge number of CHD cases. 

In contrast, South Asia has a healthier dietary pattern, lower smoking rates, and easier access to healthcare. However, with increasing urbanisation and westernisation, there is a potential risk of a surge in CHD cases in this region. 

Mechanisms of CHD Development

Before we begin to discuss the various risk factors associated with CHD, it is important to understand how CHD develops.

The gradual plaque build-up in an artery is known as Atherosclerosis. The plaque consists of fat, bad cholesterol (), and other waste products. 

Eventually, it absorbs calcium and fibrin from the blood, resulting in hard and stiff clots. 

This narrows down the lumen (diameter) of the artery and slows or blocks the blood flow to the heart. Hence, CHD starts developing. 

Key Risk Factors

Modifiable Risk Factors

These are the risk factors that can be managed by lifestyle changes or taking medications. 

High Blood Pressure 

High Blood Pressure or Hypertension refers to the constant high force of the blood pushing against the walls of the blood vessels. This continuous force leads to damage in the inner lining of the coronary arteries, making the plaque easier to deposit and retain.  

There are no prominent signs and symptoms of Hypertension unless it is higher than 180/120 mm Hg (normal: less than 120/80 mm Hg). Hence, it is also known as Silent Killer.²

It is important to check your blood pressure regularly, get yearly health check-ups, and consult a doctor if you experience headaches, heart palpitations, or nose bleeds frequently. 

High Cholesterol Levels 

In simple terms, Cholesterol can be described as a wax-like fatty substance found in the cells of our body. It helps in maintaining the structure of cell membranes, produce hormones and bile salts, and regulate the body’s metabolism efficiently.  

There are two main types of Cholesterol:³ 

LDL (Low-density lipoproteins) cholesterol 

It is also known as the ‘Bad cholesterol’. Excess of LDL cholesterol can be dangerous for the body because it starts depositing in blood vessels giving rise to CHD. 

It is advised to avoid foods that increase LDL cholesterol levels in the blood such as:^4,5

• Full-fat dairy- cream, whole milk and butter
• Red meat-  beef, pork, and lamb
• Processed meat- ham, bacon and salami
• Deep fried food 
• Baked goods and sweets
• Sugary drinks
• Palm oil, coconut oil, butter

HDL (High-density lipoproteins) cholesterol 

It is also known as the ‘Good cholesterol’ because it helps in removing excess cholesterol from the bloodstream. It carries the bad cholesterol away from the arteries to the liver, where it is processed and excreted. 

Moderate consumption of foods that boost good cholesterol can lower the risk of CHD and stroke.³ They are:⁶

• Fatty fish like salmon
• Whole grains- such as brown rice, oats, quinoa, barley
• Nuts and seeds- such as almonds, walnuts, chia seeds
• Avocados and berries
• Extra virgin olive oil

Smoking 

Similar to blood pressure, smoking also damages the inner lining of blood vessels leading to the deposition of plaque.⁷ The narrowing of blood vessels reduces blood flow and contributes to clot formation. Also, smoking triggers the activation and aggregation of platelets which are involved in clot formation. 

Obesity and Physical Inactivity 

Excessive weight or obesity often arises due to an unhealthy eating pattern and inactive lifestyle. High levels of bad cholesterol, high blood pressure, and increased risk for diabetes due to obesity leads to the development of CHD.⁸

Poor Diet 

A diet high in fats and sugars and low in fiber and minerals is a poor diet. 

A poor diet not only increases the risk of CHD but also impacts daily activities by decreasing energy levels, reducing immunity, disrupting sleep quality, and increasing the risk of memory loss.⁹

Excessive Alcohol Consumption 

Alcohol has various detrimental effects on health. It is high in calories and can lead to obesity. It can increase the level of triglycerides (a type of fat) in the blood. But most importantly, it strains heart muscles and increases blood pressure leading to the risk of CHD and stroke.¹⁰ 

No alcohol or moderate consumption of alcohol is the key to minimising such risks. 

Stress and Mental Health

When our body is exposed to stress, it tries to cope by releasing a hormone called cortisol. Besides regulating the body’s response to stress, cortisol regulates blood pressure, blood sugar, metabolism, and inflammation.¹¹

However, when the stress is prolonged, the amount of cortisol released can be very high. A study shows that the mean level of cortisol released due to stress is 9 times more than cortisol released in a relaxed state.¹²

High cortisol increases blood pressure and damages arteries. It elevates blood sugar leading to the risk of developing insulin resistance and type 2 diabetes. It can cause weight gain, especially around the belly, and also promote inflammation. All of these factors contribute to developing CHD.¹³

Non-modifiable Risk Factors

These risk factors cannot be modified but can be consulted with the doctor to take necessary measures. 

Age and Gender 

People aged 45 years or older assigned male at birth (AMAB) and people aged 55 years or older assigned female at birth (AFAB) are prone to CHD.¹⁴

Family History 

In cases where cardiovascular diseases run in the family, the reasons could be genetic or similar unhealthy lifestyle. Exercise caution in genetic cases.

Race and Ethnicity

Coronary Heart Diseases are common in people of  Black race and Hispanic ethnicity.  

Emerging and Associated Risk Factors

Diabetes 

A person with Diabetes Mellitus is 2 to 4 times more likely to be affected with Coronary Heart Disease.¹⁵ It may even prove to be fatal in some cases. High blood sugar increases blood pressure, damages blood vessels, affects heart’s electrical signals, increases heart rate, and raises LDL cholesterol in blood.¹⁶

Metabolic Syndrome 

Metabolic syndrome is a group of 5 conditions that can lead to heart disease, stroke, and diabetes. They are:¹⁷

• High blood pressure
• High blood sugar
• High level of triglycerides
• Low level of Good cholesterol or HDL
• Large waist circumference or apple-shaped body.

Having 3 or more of these conditions can increase the chance of developing a severe cardiovascular disease.¹⁷

Chronic Kidney Disease (CKD)

Kidneys are the organs responsible for filtering out waste, toxins, and excess water from the body. When they are damaged, they stop functioning optimally. Chronic Kidney Disease is a long-term condition in which kidneys lose their function over time, which may result in Kidney Failure.¹⁸ 

With CKD, the risk of cardiovascular diseases such as CHD increases due to increased blood pressure, blood sugar, cholesterol, and kidney infections.¹⁸

Inflammatory Conditions (e.g., Rheumatoid Arthritis)

Chronic inflammatory conditions such as Rheumatoid Arthritis (an auto-immune disease with joint pains) share the risk factors with CHD. High blood pressure, metabolic syndrome, obesity, and smoking are various shared factors. A person with Rheumatoid Arthritis is twice as likely to suffer from heart conditions.¹⁹

Consequences of Untreated CHD

Untreated CHD can lead to various complications such as:

• Heart Attack 
• Heart Failure 
• Irregular heartbeat or Arrhythmia  
• Sudden Cardiac Arrest

Prevention and Risk Management

Lifestyle Modifications:

Diet 

A healthy diet is the first step towards preventing or managing CHD. Doctors emphasise consuming diets such as the Mediterranean diet and DASH diet.

A Mediterranean diet consists of plenty of fruits, vegetables, whole grains, beans, and legumes. Olive oil is the only source of fat. Dairy products, eggs, and fish are consumed in moderation.²⁰

The DASH (Dietary Approach to Stop Hypertension) diet focuses on consuming a fat-free, low-salt, and low-dairy diet with vegetables and fruits.²¹ 

Regular Physical Activity 

Regular exercises as simple as walking, dancing, or swimming can effectively reduce the risk of developing CHD. Make sure that you don’t over-exercise. Training under a professional with appropriate equipment can reduce the risk of injury.

Smoking Cessation 

Quit smoking, vaping, or using any other tobacco products. You can try various quit-smoking products such as Nicotine patches, gums, lozenges, sprays, and inhalers..²² Consult a healthcare professional for an effective strategy combined with a quit-smoking product.

Passive smoking, meaning breathing in other people’s smoke, is also harmful and should be avoided.  

Weight Management 

Maintaining a healthy weight can reduce many risk factors such as obesity and type 2 diabetes. Consult your healthcare team to know your healthy weight. You can calculate your Body Mass Index (BMI) here by inserting your height and weight. 

Stress Management Techniques

Taking time for simple stress management techniques like deep breathing or positive self-talk can do wonders. The best practices for a calmer mind are Meditation and Yoga.
(Read more here: 3 Tips to Manage Stress)

Medical Interventions:

Medications  

To manage CHD, certain medications can be prescribed by doctors:²³ 

• Statins help in lowering cholesterol levels and reducing the risk of further complications 
• Beta-blockers help in lowering the blood pressure 
• Low-dose aspirin helps in preventing clotting by thinning the blood 
• Nitrates help in widening blood vessels by letting more blood pass and lowering blood pressure 

Surgical Procedures (Angioplasty, Bypass Surgery) 

Surgical procedures such as angioplasty, bypass surgery, or heart transplant can be performed based on the severity of the condition.²³

• Coronary Angioplasty involves using a small balloon to push the fatty tissue out of the narrowed vessel followed by placing a metal stent (a wire mesh tube) to hold it open. 
• Coronary Artery Bypass Graft (CABG) involves inserting (grafting) a healthy artery from another part of the body and using it to bypass the blockage, allowing better blood flow to the heart. 
• Heart Transplant involves replacing a severely damaged heart with a healthy donor heart. 

Regular Health Screenings

A person at risk of heart disease such as CHD must go for health screening regularly. A health screening is done to check for potential diseases or conditions in the absence of the symptoms. 

Psychological Support and Rehabilitation

Besides medicines and surgeries, psychological support and rehabilitation are equally essential for the emotional well-being and long-term health of the person experiencing CHD.

It helps in managing anxiety and stress associated with the condition.
Rehabilitation programs provide education on heart-healthy living and supervised exercises. 

Recent Research and Future Directions

Recent research and ongoing studies focus on innovations in treatment such as:

• Genetic and Personalised Medicine- involving genetic risk assessment, new drug therapies like PCSK9 inhibitor drugs, and targeted treatments based on genetic profile. 
• Role of AI and Technology in CHD Management- AI-based wearable technologies can help in predicting and monitoring risk factors timely and accurately. 

Summary

Coronary Heart Disease is a condition involving the narrowing of coronary arteries by fatty deposits called plaque. It presents as shortness of breath, chest pain, and discomfort. It can be prevented and managed by lifestyle modification and medicines. Severe cases involve surgery. Support and rehabilitation help in managing the emotional and mental well-being of the patient. Various studies and research are going on for early detection and symptom-targeted management of this condition.