Prevention, lifestyle and dietary advice
Cardiovascular disease (defined as diseases of the heart and blood vessels) is the leading cause of death in the UK and worldwide. In the UK, 1 in 3 deaths is attributable to cardiovascular disease (CVD). CVD includes conditions such as angina, heart attacks, heart failure, stroke and blood pressure. The incidence of CVDis higher in men than women before the menopause. After menopause, this association nolonger exists, and the incidence as well as the rate of progressionof CVD is similar in both sexes. CVD increase with age and predominantly affects people over the age of 50 years.
The major contributor to cardiovascular disease is coronary artery disease (CAD). This occurs when cholesterol and other substances are deposited in the arteries of the heart resulting in plaques that narrow the coronary arteries. This disease process is known as atherosclerosis in the medical literature. The narrowed arteries result in less oxygen-rich blood being delivered to the heart muscle, during periods of physical or mental stress, culminating in chest pain (angina pectoris). If the plaque ruptures with ensuing clot formation on top that completely blocks the artery, then a myocardial infarction (heart attack) occurs. Myocardial infarction with the devastating complication of sudden death can sometimes be the first presentation of patients with underlying CAD, which can often be asymptomatic.
Although chest pain on exertion is the commonest symptom and is often described as a heaviness or pressure like pain, some patients may experience only breathlessness or present with abnormal heart rhythms. Furthermore, the description of chest pain can often be difficult to explain, which can result in a delay in diagnosis. Many risk factors can contribute to the development of CAD that include: a family history, hypertension, high cholesterol, poor diet, sedentary lifestyle, diabetes mellitus and smoking. Anyone with a history of exertional chest pain, particularly with risk factors, should seek medical advice. Anyone without symptoms but has a strong family history of heart disease should be assessed for risk factors, and have their estimated 10-year CVD risk calculated. This will allow effective preventative measures to be instituted (see section on preventative cardiology).
Diagnosing Coronary Artery Disease
The likelihood of coronary artery disease can be determined from risk estimate tables taking into account symptoms, clinical assessment, the electrocardiogram (ECG) and further diagnostic testing. These diagnostic tests include exercise stress testing, calcium scoring (a test used to determine the quantity of calcium in the arteries of the heart, which correlates with the amount of atherosclerosis), and the use of other specialised imaging tests. The gold standard (definitive) test to confirm CAD is coronary angiography. This is performed by inserting catheters (specialised tubes) into the coronary arteries either from the groin (femoral approach) or the wrist (radial approach).
Treatment options for patients diagnosed with CAD include: risk factors modification and reduction, commencing medication, angioplasty/stent insertion (a balloon is used to dilate the narrowed artery followed by the insertion of a metal tube – a stent) or coronary artery bypass surgery. Each patient is managed individually according to the patients’ expectations, degree of symptoms, coronary anatomy and associated medical conditions.
Prevention is better than cure and general healthy living will reduce the risk of the development and progression of CAD. It is recommended that people older than 40 years should have their CVD risk estimated (determined from risk tables), on a regular basis. If the estimated 10-year risk is 20% or greater, then life style alteration and risk factor modification should be promptly instituted (including consideration for starting a tablet to lower cholesterol). Preventative measures should include:
- A healthy diet. This can have a great impact on health and will help control weight, cholesterol, and blood pressure. A healthy diet should include: (i) 5 portions of fruits and vegetables a day. (ii) two portions of fish per week with at least one portion being an oily fish such as salmon, mackerel, trout, sardines and fresh tuna. (iii) Reducing the total amount of fat intake particularly saturated fats. This should be replace with monounsaturated and polyunsaturated fats. (iv) A reduction of salt intake particularly people with borderline, elevated or a family history of blood pressure.
- A reduction of alcohol intake complying with recommendations (less than 14 units for females and 21 units for males per week). A unit of alcohol is roughly equal to: half a pint of ordinary strength beer, lager or cider; a pub measure (25ml) of spirits; or a standard pub measure (50ml) of wine, sherry or port.
- Exercise. It is important to try and get at least 30 minutes of exercise 5 days or more a week. The exercise programme should involve a sustained level of activity sufficient to make breathing heavy but not puffing or panting.
- Stop smoking. A year after discontinuation the risk of a heart attack falls to about half that of a smoker.
- Avoid stress. Stress can cause blood pressure elevation that can predispose to cholesterol plaque rupture and heart attacks. Avoidance of stressful situations or engaging in activities to reduce or manage stress such as exercise, yoga, breathing and relaxation techniques can often be beneficial. Furthermore, stress can lead to adverse coping behaviour such as smoking, overeating and excess alcohol intake that can further increase the risk of cardiovascular disease.
- Measure a cholesterol level. Cholesterol is important to maintain the integrity of all cells in the body. It is also needed to manufacture hormones and vitamins. However, too much cholesterol is associated with heart, stroke and circulation diseases. The total cholesterol level should generally be less than 5 mmol/l. If there is a history of angina/heart attacks, stroke, circulation problems or diabetes, then the cholesterol level should be less than 4 mmol/l. By far the commonest reason for an elevated cholesterol is dietary causes. However, there is a condition called familial hypercholesterolaemia that is found in 1 in 500 of the population. This condition is associated with significantly elevated cholesterol (more than 7.5mmol/l) and premature heart attacks less than 55 years in men and 60 years in women. Once diagnosed immediate treatment with a tablet to lower cholesterol (a statin) and lifestyle changes are recommended.