Prevention of CAD is linked with the alteration of modifiable risk factors. Primary prevention can be explained as the prevention of atherosclerosis, which is the main cause for ischaemic heart disease (IHD), ischaemic stroke, and peripheral vascular disease (PVD). Secondary prevention can be defined as the treatment of the atherosclerotic disease or its complications. The goal of prevention is to minimise the prevalence of first or repeated clinical events due to CAD, peripheral vascular disease, and stroke.
There are several major modifiable risk factors of coronary artery disease (CAD). They are,
- Cigarette smoking
- Hypertension
- Hyperlipidaemia
- Diabetes mellitus
- Unhealthy diet and obesity
Cigarette smoking
Direct or passive cigarette smoking is one of the main causes of coronary artery disease (CAD). The risk of developing CAD is two to four times higher in smokers compared to that of non-smokers. It is directly linked to the number of cigarettes smoked, specially in men. About 20 % deaths from CAD in men and 17 % of deaths from CAD in women are because of smoking. Individuals, who smoke one pack of cigarettes daily, have more than two times higher risk of developing a heart attack (myocardial infarction or MI) than non-smokers. Smoking is a strong independent risk for sudden cardiac death in people with CAD. If you already have other risk factors of CAD, cigarette smoking can significantly increase the risk for CAD. Individuals, who smoke pipes or cigars have a slightly lower risk of developing CAD compared to cigarette smokers. However, they have a significantly higher risk of death from CAD and probably stroke than cigarette smokers. Stopping smoking will lower the risk of CAD by 25 %. The risk of developing CAD from cigarette smoking drops to almost normal after ten years of cessation.
Hypertension
Hypertension is usually defined as a systolic blood pressure of 140 mmHg or above or a diastolic blood pressure of 90 mmHg or above. Both systolic and diastolic hypertension are linked with an elevated risk of CAD. Hypertension significantly raises the workload of the heart. Therefore, as an adaptation, the heart muscle (myocardium) becomes thicker and stiffer. This process is not healthy and impairs normal function of the heart gradually. It also raises the risk of heart attack (myocardial infarction or MI), heart failure, stroke, and kidney failure. If hypertension exists with one of the other risk factors of CAD such as smoking, obesity, hyperlipidaemia, or diabetes, the risk of developing a heart attack or stroke raises several times. About 14 % of deaths in men and 12 % of deaths in women from CAD are because of hypertension. Both medication and lifestyle changes like weight loss, regular exercise, and decrease in alcohol and salt intake can successfully lower blood pressure.
Hyperlipidaemia
High blood cholesterol, especially when linked with a low level of HDL (high-density lipoproteins), is strongly associated with coronary atherosclerosis. HDL cholesterol removes cholesterol from the blood via the liver. Low HDL cholesterol is also linked with a poor prognosis after a myocardial infarction (heart attack). High blood TG (triglyceride) is also independently related to coronary atheroma. If hyperlipidaemia exists with other risk factors such as hypertension and smoking, the risk of CAD raises even more. An individual’s blood cholesterol level is usually affected by gender, age, diet, and heredity.
Measurement of the fasting lipid profile should be carried out on individuals with an elevated risk of CAD.
Blood cholesterol levels can be lowered by medication, regular exercise, and dietary modifications. About 45 % deaths in men and 47 % deaths in women from CAD are because of an elevated blood cholesterol level (>5.2 mmol/L or >200 mg/dL).
Your blood cholesterol goals need to be:
- Total cholesterol: Less than 5.2 mmol/L or 200 mg/dL
- LDL (low-density lipoprotein) cholesterol:
- For people with low risk for CAD: Less than 4.1 mmol/L or 160 mg/dL
- For people with intermediate risk for CAD: Less than 3.4 mmol/L or 130 mg/dL
- For people with high risk for CAD (including people with existing diabetes or heart disease): Less than 2.6 mmol/L or 100 mg/dL
- HDL (high-density lipoprotein): 1 mmol/L (40 mg/dL) or above for men and 1.3 mmol/L (50 mg/dL) for women
- Triglycerides (TG): Less than 1.7 mmol/L or 150 mg/dL
If your blood HDL level is below 1.0 mmol/L (40 mg/dL), you need to take treatments. Exercise, not smoking, alcohol in moderation, and low-triglyceride levels increase the blood HDL level. A one per cent reduction in blood cholesterol levels lowers the risk of ischaemic heart disease by two to three per cent.
Hyperlipidaemia can be managed as follows:
Statins
Statins (e.g. Simvastatin or Pravastatin) can lower the mortality by 24-30 % in primary and secondary prevention. If the dose of statin (e.g. Atorvastatin) is adjusted to achieve a blood LDL level of less than 2.6 mmol/L (100 mg/dL), up to 50 % mortality reduction can be achieved.
Fibrates
Fibrates (e.g. Bezafibrate, Fenofibrate, Ciprofibrate, Gemfibrozil) can reduce the number of CAD events significantly in diabetes and people with low HDL and high triglycerides (TG).
Diet
Mediterranean diet can lower 75 % of CAD events in people, who had a myocardial infarction (heart attack) before.
Lowering the blood cholesterol slows the advancement and causes regression of the coronary atherosclerosis. Lipid lowering with statins can reduce the mortality, new CAD events, as well as the need for revascularisation.
Diabetes mellitus
Diabetes mellitus is strongly linked with atherosclerosis hence CAD. Diabetes considerably raises the risk of developing CAD. Even when blood glucose is controlled well, diabetes increases the risk of stroke and CAD. If diabetes is not under control, the risk is even higher. If you don’t control blood sugar, you are more prone to develop CAD earlier compared to other people. Pre-menopausal women with diabetes have an increased risk of CAD because, diabetes destroys the protective effect of Oestrogen. Men have two- to four-fold higher annual risk of CAD, and women have three- to five-fold greater annual risk of CAD, if they have type 2 diabetes mellitus. Diabetes can increase the effect of other risk factors for CAD like hyperlipidaemia, hypertension, obesity, and smoking. At least 65 % individuals with diabetes die from some form of cardiovascular disease. Controlling Blood sugar and other risk factors is really important to manage CAD. Healthy diet, regular exercise, and medications can manage diabetes. Keeping up your body weight within the normal range will also help control blood-sugar level.
Unhealthy diet and obesity
Diet
Diet rich in saturated fat is linked with 31 % of ischaemic heart disease and 11 % of stroke. Low intake of antioxidant rich foods such as fruit and vegetables increases the risk of CAD further. Up to 30 % deaths from CAD events are because of unhealthy diets. Reduced-fat intake (specially saturated fat, trans fat, and cholesterol), reduced-salt intake, reduced-refined sugars, and increased complex carbohydrate intake will help reduce the number of CAD events. It is better to take nutrient rich, low-calorie diet. Vegetables, fruit, fish, lean protein, nuts, whole-grain, foods rich in fibre, and low-fat or fat-free dairy products are good options. The daily consumption of fruit and vegetables should be about 400 g (0.9 lbs or at least five portions). Modification of the diet significantly lowers the risk of CAD in the primary and secondary prevention. A healthy diet also helps control other risk factors for CAD such as hyperlipidaemia, hypertension, diabetes, obesity, and overweight.
Body weight
Obesity and being overweight raise the risk of CAD. About five per cent deaths in men and six per cent deaths in women from CAD are because of obesity. If you are obese or overweight with fat, mainly in the abdomen and waist (central obesity), the risk of stroke and CAD will be higher even without other risk factors. Excess body weight can raise the work load of the heart, increasing the blood pressure. It also increases blood cholesterol, triglyceride, and lowers HDL cholesterol. Obesity and being overweight is linked with diabetes too. Central obesity can be recognised by a high waist/hip ratio. If you lose the bodyweight by even 10 %, you can lower the risk of CAD. Eating a healthy diet and regular exercising decrease the body weight hence the risk of ischaemic heart disease significantly.
Exercise
Weight loss by a healthy diet and regular exercise lowers the incidence of CAD as well as diabetes. Exercise improves the action of insulin by inhibiting insulin resistance. Regular physical activities help control blood sugar, cholesterol, hypertension, as well as obesity. About 36 % of deaths in men and 38 % of deaths in women from CAD are due to lack of exercise. Individuals, who do not exercise, have higher death and CAD rate than people, who participate in even mild to moderate physical activities. More vigourous exercises are linked with more health benefits. Regular aerobic exercises help achieve maximum benefits. Aerobic physical activities should involve all muscle groups, including in the arms, legs, and back rhythmically and steadily. They increase the heart rate and breathing considerably. Therefore, aerobic exercises strengthen the heart and lungs. It is recommended to participate in at least moderate intensity physical activities such as brisk walking, climbing the stairs, and cycling for a minimum of 30 minutes on five or more days a week.
Related Links:
What Is Ischaemic Heart Disease?
Process of Atherosclerosis and Thrombosis
Complications of Atherosclerosis
Introduction: Risk Factors of Atherosclerosis
Non-modifiable Risk Factors of CAD
Other Risk Factors of CAD
Cardiovascular Disease (CVD) Prevention Policy
No comments:
Post a Comment
We hold the right to delete or edit any of your comments for any reason. Please, add your valuable comment decently. If you add your comment for the purpose of spamming, profanity or ad hominem attacks, your comment will be banned and deleted.