A myocardial infarction, commonly known as a heart attack, occurs when blood flow to the heart becomes blocked. This blockage is usually caused by a buildup of fat, cholesterol, and other substances that form plaque in the coronary arteries (the vessels that supply the heart). Sometimes the plaque can rupture and form a clot that obstructs blood flow. Once circulation is interrupted, part of the heart muscle can become damaged or die. A heart attack, or myocardial infarction, can be fatal.
High levels of low-density lipoprotein (LDL) cholesterol—the “bad” cholesterol—are the most common cause of artery narrowing. Elevated triglycerides, a type of blood fat linked to diet, also increase heart attack risk. Therefore, cholesterol is one of the key risk factors for myocardial infarction.
Cholesterol helps your body build new cells, insulate nerves, and produce hormones. Normally, the liver makes all the cholesterol the body needs. But cholesterol also enters your body from food, such as animal-based foods like milk, eggs, and meat. Too much cholesterol in your body is a risk factor for heart disease.
There are two forms of cholesterol that many people are familiar with: Low-density lipoprotein (LDL or "bad" cholesterol) and high-density lipoprotein (HDL or "good" cholesterol.) These are the forms in which cholesterol travels in the blood. LDL is the main source of artery-clogging plaque. HDL actually works to clear cholesterol from the blood.
Triglycerides are another fat in our bloodstream. Research is now showing that high levels of triglycerides may also be linked to heart disease.
High cholesterol itself does not cause any symptoms, so many people are unaware that their cholesterol levels are too high. Therefore, it is important to find out what your cholesterol numbers are. Lowering cholesterol levels that are too high lessens the risk for developing heart disease and reduces the chance of a heart attack or dying of heart disease, even if you already have it.
Some recommend that everyone over age 20 should get their cholesterol levels measured at least once every 5 years. The test that is performed is a blood test, that includes:
Total cholesterol level
LDL (the "bad" cholesterol)
HDL (the "good" cholesterol)
Triglycerides
Here's how to interpret your cholesterol numbers:
Total Cholesterol
Less than 200 - Desirable
200 – 239 - Borderline High
240 and above - High
LDL Cholesterol
Less than 100 - Optimal
100 – 129 - Near optimal/above optimal
130 – 159 - Borderline high
160 – 189 - High
190 and above - Very high
HDL*
60 or more - Desirable - helps to lower risk of heart disease
Less than 40 - Major risk factor -- increases the risk for developing heart disease
*HDL (good) cholesterol protects against heart disease, so for HDL, higher numbers are better
Triglycerides
Less than 150 - Normal (desirable) heart disease
150-199 - Borderline high
200-499 - High
>500 – Very high
Anyone can get high cholesterol, and it can be caused by many different things. Some things you can control like lifestyle habits, others you can’t. As long as you take care of the things you can control, you’ll help lower your risk. Factors that can affect your cholesterol levels include:
Diet. Saturated fat, trans fat, carbohydrates, and cholesterol in the food you eat increase cholesterol levels. Reducing the amount of saturated fat, trans fats and sugars in your diet helps lower your blood cholesterol level. Increasing the amount of fiber and plant-derived sterols can also help lower LDL cholesterol.
Weight. In addition to being a risk factor for heart disease, being overweight can also increase your cholesterol. Losing weight can help lower your LDL, total cholesterol levels, and triglyceride levels, as well as raise your HDL.
Exercise. Regular exercise can lower LDL cholesterol and raise HDL cholesterol. You should try to be physically active for 30 minutes every day.
Age and Gender. As we get older, cholesterol levels rise. Before menopause, women tend to have lower total cholesterol levels than men of the same age. After menopause, however, women's LDL levels tend to rise.
Heredity. Your genes partly determine how much cholesterol your body makes. High blood cholesterol can run in families.
Medical conditions. Occasionally, a medical condition may cause an elevation of cholesterol levels in the blood. These include hypothyroidism (an underactive thyroid gland), liver disease and kidney disease.
Medications. Some medicines, like steroids and progestins, may increase "bad" cholesterol and decrease the "good" cholesterol.
Smoking. It can lead to high cholesterol levels, and the build-up of tar it causes in your arteries makes it easier for cholesterol to stick to your artery walls.
Your risk of heart and circulatory disease is increased if you have high cholesterol as well as other risk factors, such as:
smoking
high blood pressure
being physically inactive
being overweight
having diabetes
family history of premature coronary heart disease (before 55 for men and before 65 for women)
being of South Asian origin
The more risk factors you have, the higher your risk of developing a heart or circulatory disease such as a heart attack, stroke or vascular dementia.
The main goals in treating high cholesterol are to lower your LDL levels and lower your risk of cardiovascular disease. To lower cholesterol, eat a heart-healthy diet, exercise regularly, and maintain a healthy weight. Some may also need to take cholesterol-lowering drugs.
Doctors determine your "goals" for lowering LDL based on the number of risk factors you have for heart disease. Based on your risk, your doctor will determine the intensity of LDL reduction you need, and prescribe a medication accordingly.
Including whether you are also diagnosed with cardiovascular disease. Many health care providers recommend treating anyone with CVD with high-dose statin therapy. This includes those with coronary heart disease and who have had a stroke.
For those who do not have CVD, treatment is determined by your individual risk for developing heart disease. That risk can be estimated using calculators which factor your age, sex, medical history, and other characteristics. If your risk is high (such as a 7.5 or 10 percent risk of developing CVD over 10 years), your doctor may start you on treatment preventively. They generally keep in mind your preferences towards taking medication in general. For those people whose risk is unclear, a coronary artery calcium score, which is a screening test looking for calcium (an indication of atherosclerosis) in the arteries, can help determine the need for statins.
For both those who have CVD and those who do not, when the decision is made to start medication, the first choice is usually a statin.
Other special groups who may need treatment:
People with high triglyceride levels may benefit if they have other risk factors
People with diabetes: are at high risk
Older adults
Cholesterol-lowering drugs include:
Statins
Cholesterol absorption inhibitors
PCSK9 inhibitors
Niacin
Fibric acid derivatives
Bile-acid resins
Cholesterol-lowering medicine is most effective when combined with a healthy diet and exercise program.
Some people with high cholesterol achieve the best results with combination drugs. These drugs treat cholesterol problems and are sometimes combined with medications like blood pressure drugs in one pill.
The side effects of cholesterol-lowering drugs include:
Muscle aches*
Abnormal liver function
Allergic reaction (skin rashes)
Heartburn
Dizziness
Abdominal pain
Constipation
Decreased sexual desire
Memory problems
*If you have muscle aches, call your doctor immediately. This could be a sign of a life-threatening condition.
https://www.mayoclinic.org/diseases-conditions/heart-attack/symptoms-causes/syc-20373106
https://www.webmd.com/heart-disease/guide/heart-disease-lower-cholesterol-risk
https://www.bhf.org.uk/informationsupport/risk-factors/high-cholesterol
