Heart attack, also known as myocardial infarction (MI), is a life-threatening medical emergency that occurs when the heart muscle doesn’t receive enough oxygen and nutrients.

It’s a leading cause of death globally, with over 17 million fatalities each year. There are several factors that increase the risk of having a heart attack, but one of the most deadly duos is high cholesterol and high blood pressure.

Let’s explore how these two conditions can wreak havoc on your heart and what you can do to protect yourself.

What Is High Cholesterol?

Cholesterol is a waxy, fat-like substance that’s necessary for building cell walls, producing hormones, and digesting food. It’s mainly produced by the liver, but we also get it from some foods, such as meat, cheese, and eggs.

There are two types of cholesterol: low-density lipoprotein (LDL) and high-density lipoprotein (HDL). LDL cholesterol is often called “bad” cholesterol because it can accumulate in the arteries, form plaques, and obstruct blood flow.

HDL cholesterol, on the other hand, is often called “good” cholesterol because it can help remove excess cholesterol from the bloodstream and transport it back to the liver for processing.

High cholesterol, also known as hypercholesterolemia, occurs when the levels of LDL cholesterol, total cholesterol, or triglycerides (another type of fat in the blood) are elevated.

It’s a major risk factor for heart attack, stroke, and other cardiovascular diseases because it can cause atherosclerosis, which is the hardening and narrowing of the arteries due to plaque buildup. Atherosclerosis can reduce the blood supply to the heart muscles and increase the likelihood of blood clots, which can trigger a heart attack or a stroke.

What Is High Blood Pressure?

Blood pressure is the force of blood against the walls of the arteries as the heart pumps it.

It’s measured in millimeters of mercury (mmHg) and expressed with two numbers: systolic pressure (the top number) and diastolic pressure (the bottom number). A normal blood pressure reading is around 120/80 mmHg, but high blood pressure, also known as hypertension, is diagnosed when the systolic pressure is 130 mmHg or higher and/or the diastolic pressure is 80 mmHg or higher.

High blood pressure is a silent but deadly condition because it usually doesn’t cause noticeable symptoms until it damages the organs.

High blood pressure can cause several complications, such as heart attack, stroke, heart failure, kidney disease, and vision loss.

It’s a major risk factor for heart attack because it can weaken and enlarge the heart muscles, damage the blood vessels, and promote the formation of blood clots. High blood pressure can also accelerate the atherosclerosis process by making the artery walls more vulnerable to LDL cholesterol and other inflammatory substances.

How High Cholesterol and High Blood Pressure Work Together?

High cholesterol and high blood pressure are not independent risk factors for heart attack; they often coexist and interact with each other to amplify the damage.

Studies have shown that people with both high cholesterol and high blood pressure have a much higher risk of heart attack than those with only one or neither. Here are some ways in which high cholesterol and high blood pressure can work together to harm your heart:.

1. Atherosclerosis

Atherosclerosis is a complex process that involves the accumulation of lipids, immune cells, smooth muscle cells, and connective tissue in the arterial walls.

High levels of LDL cholesterol can trigger the formation of foam cells, which are macrophages (immune cells) that engulf and store lipids, especially cholesterol. Foam cells can become trapped in the intimal layer of the arterial walls and form fatty streaks, which are the earliest signs of atherosclerosis.

Over time, fatty streaks can progress to fibrous plaques, which are composed of collagen, elastin, and smooth muscle cells, and are more unstable and likely to rupture. A ruptured plaque can expose the thrombogenic (clotting) substances, such as tissue factor and von Willebrand factor, and trigger the formation of blood clots, which can totally or partially occlude the artery and cause a heart attack.

High blood pressure can contribute to atherosclerosis by several mechanisms. Firstly, it can cause endothelial dysfunction, which is the impairment of the inner lining of the blood vessels.

Endothelial dysfunction can reduce the production of nitric oxide, a vasodilator that helps relax the arteries and reduce the blood pressure. Without enough nitric oxide, the blood vessels become stiffer and more resistant to blood flow, which can raise the blood pressure even more.

Endothelial dysfunction can also promote the adhesion and infiltration of immune cells, such as monocytes and lymphocytes, into the arterial walls, which can exacerbate the inflammation and oxidation of the lipids and destabilize the plaques. Secondly, high blood pressure can increase the shear stress and mechanical forces on the arterial walls, which can damage the endothelial cells, disrupt the smooth muscle cells, and enhance the permeability of the intima.

These changes can facilitate the deposition of LDL cholesterol and other lipids in the arterial walls and promote the migration and proliferation of the smooth muscle cells, which can form the fibrous plaques.

2. Thrombosis

Thrombosis is the formation of a blood clot inside a blood vessel. It’s a natural response to injury or damage because it can prevent excessive bleeding and aid in the repair and healing process.

However, thrombosis can also be pathological when it occurs in diseased and obstructed vessels, such as those affected by atherosclerosis. Thrombosis can cause ischemia, tissue death, and organ failure, depending on the location and severity of the clotting.

High cholesterol and high blood pressure can increase the risk of thrombosis by different mechanisms.

As mentioned earlier, high cholesterol can lead to the development of unstable and rupture-prone plaques, which can expose the procoagulant substances and trigger the formation of blood clots. High blood pressure can also promote thrombosis by inducing shear stress and turbulence of the blood flow, which can damage the endothelial cells and the platelets, and activate the coagulation cascade.

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High blood pressure can also impair the fibrinolysis, which is the process of dissolving the clots and preventing their enlargement and persistence. Fibrinolysis is mediated by plasmin, an enzyme that breaks down the fibrin strands that hold the clots together. Plasminogen, the precursor of plasmin, is activated by tissue-type plasminogen activator (tPA), which is produced by the endothelial cells.

High blood pressure can reduce the secretion and availability of tPA, which can compromise the fibrinolysis and enhance the thrombosis.

3. Hypertensive Heart Disease

Hypertensive heart disease is a term used to describe the structural and functional changes that occur in the heart in response to high blood pressure. The heart is a muscular organ that works as a pump to circulate the blood throughout the body.

It’s composed of four chambers: the right and left atria and the right and left ventricles. The atria receive the blood from the veins and transport it to the ventricles, which contract to propel the blood to the arteries and distribute it to the organs and tissues.

The heart also has four valves that regulate the blood flow and prevent backflow. The heart requires a continuous supply of oxygen and nutrients to function properly, which is provided by the coronary arteries, the blood vessels that wrap around the heart muscles.

High blood pressure can damage the heart by several mechanisms. Firstly, it can increase the workload and the resistance of the heart muscles, which can make them hypertrophied (enlarged) and less compliant (stiff).

Hypertrophied and stiff muscles require more oxygen and energy to contract and relax, which can strain the coronary arteries and reduce the blood flow to the heart. Hypertrophied and stiff muscles can also impair the filling and emptying of the heart chambers, which can lead to heart failure or arrhythmia (abnormal heartbeat).

Secondly, high blood pressure can cause endothelial dysfunction in the coronary arteries, which can reduce the vasodilation and increase the vasoconstriction, and impair the blood supply to the heart muscles. Thirdly, high blood pressure can increase the risk of atherosclerosis in the coronary arteries, which can cause angina (chest pain), myocardial ischemia (heart muscle damage), or a heart attack.

How to Prevent or Control High Cholesterol and High Blood Pressure?

The good news is that high cholesterol and high blood pressure are preventable and controllable with lifestyle changes and medical treatments. Here are some tips that can help you keep your heart healthy:.

1. Adopt a heart-healthy diet

Eat a balanced and varied diet rich in fruits, vegetables, whole grains, lean protein, and healthy fats, and low in saturated and trans fats, added sugars, and sodium.

Choose foods with high fiber, vitamins, minerals, and antioxidants that can promote a healthy heart and a low LDL cholesterol level, such as nuts, legumes, fish, olive oil, avocados, and berries. Limit your intake of red meat, processed meat, cheese, butter, and fried and fast foods that can raise your LDL cholesterol and blood pressure.

If you have high blood pressure, try to reduce your sodium intake to less than 2,300 milligrams per day, or less than 1,500 milligrams if you’re over 50 years old, African American, or have other risk factors.

2. Exercise regularly

Aim for at least 150 minutes of moderate-intensity aerobic exercise or 75 minutes of vigorous-intensity aerobic exercise per week, or a combination of both.

Moderate-intensity exercises include brisk walking, cycling, swimming, or dancing, while vigorous-intensity exercises include running, playing basketball, soccer, or tennis, or doing high-intensity interval training (HIIT). Exercise can help lower your LDL cholesterol, decrease your blood pressure, improve your insulin sensitivity, reduce your stress and anxiety, and boost your mood and energy.

3. Stop smoking

If you smoke or use tobacco products, quit as soon as possible. Smoking can damage your blood vessels, reduce your HDL cholesterol, increase your blood pressure, and promote atherosclerosis and clotting.

Smoking can also increase your risk of other health problems, such as cancer, lung disease, and infections.

4. Maintain a healthy weight

Try to achieve and maintain a healthy body weight that’s appropriate for your age, height, and sex.

A BMI (body mass index) between 18.5 and 24.9 is considered healthy, while a BMI of 25 or more is classified as overweight, and a BMI of 30 or more is classified as obese. Excess weight, especially around the waist, can increase your LDL cholesterol, blood pressure, and insulin resistance, and worsen your other risk factors for heart attack.

5. Manage your stress

Find healthy ways to cope with your stress, such as meditation, yoga, tai chi, deep breathing, or socializing.

Stress can raise your blood pressure, increase your cortisol (stress hormone) level, and promote inflammation and oxidative stress in your body. Chronic stress can also lead to unhealthy behaviors, such as overeating, smoking, or drinking, that can further harm your heart.

6. Take medications as prescribed

If you have high cholesterol or high blood pressure, your doctor may prescribe medications to lower them.

Common medications for high cholesterol include statins, which reduce the production of cholesterol in the liver, and PCSK9 inhibitors, which enhance the removal of LDL cholesterol from the bloodstream.

Common medications for high blood pressure include diuretics, which decrease the fluid volume in the blood vessels, beta-blockers, which reduce the heart rate and contractility, ACE inhibitors, which block the vasoconstrictor effect of angiotensin II, and calcium channel blockers, which relax the arterial walls and reduce the resistance.

Conclusion

High cholesterol and high blood pressure are two of the most dangerous risk factors for heart attack.

They can interact with each other to damage the heart muscles, arteries, and blood vessels, and promote atherosclerosis, thrombosis, and hypertensive heart disease. Fortunately, they are also modifiable risk factors that can be prevented or controlled with lifestyle changes and medical treatments.

By adopting a heart-healthy diet, exercising regularly, quitting smoking, maintaining a healthy weight, managing your stress, and taking medications as prescribed, you can reduce your risk of heart attack and live a longer, healthier life.