Angina pectoris and heart attack (coronary heart disease)

What is coronary heart disease?

Coronary heart disease is a condition caused by anomalies in the coronary arteries that result in chest pain. Coronary heart disease can be broken down into angina pectoris and acute heart attack.

1. Angina pectoris is caused by the thickening and hardening of the walls of the arteries (arteriosclerosis or atherosclerosis), which results in the narrowing of the coronary arteries. The coronary arteries supply oxygen-rich blood to the heart muscle.
2. A heart attack or myocardial infarction occurs when a part of the heart muscle (the myocardium) dies off after the blood supply to that part has been cut off. The cause is usually a blood clot (thrombus) or a piece of arteriosclerotic plaque. The clot or piece of plaque can be dissolved within a few days but there will then usually have been irreparable damage to the heart muscle.

The risk factors for coronary heart disease are: smoking, fatty diet, diabetes, high blood pressure, high cholesterol, overweight and a previous history of heart disease or a high prevalence of cardiovascular disease in the family. ⁵¹⁶

What are the complaints associated with coronary heart disease?

Chest pain is a feature in both diagnoses. In angina pectoris, the pain usually comes on with exertion and subsides with rest. A heart attack involves sudden, severe pain in the chest that persists for a long time.

The pain may radiate to the throat, neck, arms, back and upper abdomen. Most patients suffer from respiratory distress or shortness of breath, and an oppressive and congestive sensation. In addition, there may be symptoms such as fainting, sweating, pale skin, anxiety, nausea and vomiting. ⁵¹⁶

This unpleasant experience can be expressed as a change in behaviour, especially in people who are unable to communicate adequately. A study of the symptoms of heart disease in people with intellectual disabilities showed that more than half of the patients expressed the symptoms in an atypical manner. They complained, for example, about abdominal pain and nausea, rubbed their stomachs, or said they felt dizzy or unwell, and in two people the complaints were initially mistaken for an epileptic attack. ⁵¹⁷

However, in some cases – 'silent' heart attacks – a heart attack may not produce any symptoms at all.

How common is coronary heart disease in the general population? ²²⁰ , ²²¹

On 1 January 2011, there were an estimated 604,500 people with coronary heart disease in the Netherlands. The prevalence was 4.7% for men at that point in time and 2.6% for women. Coronary heart disease is the second cause of death for men (after lung cancer). It is the third cause of death in women (after dementia and stroke). The mortality rate for cardiovascular disease has fallen sharply in the past thirty years. This is partly due to prevention (eating more vegetables and fruit and less saturated fat, stopping smoking and more exercise, losing weight) but particularly to improvements in health care, as a result of which people receive better treatment and die less often as a result of a heart attack. ⁵¹⁸

Studies are conducted in a structural way of the incidence rate for coronary disease. The incidence of coronary heart disease in people aged 50 years and over is 7.26 per 1000 person years.  ^{517   518}

How common is coronary heart disease in people with intellectual disabilities?

A Dutch study in two institutions for people with intellectual disabilities (510 clients aged 50 and over) showed that the lifetime prevalence rate for heart attack was 5.7%. In the GP population of people aged 50 years and over selected for comparison, the prevalence was 4.4%, which was not significantly different. ²²²

The incidence of coronary heart disease (heart attack and angina pectoris) in the elderly population with intellectual disabilities is the same as the rate to those in the general population of older people: 6.45 per 1000 years. ⁵¹⁷

Cardiovascular disease (including coronary heart disease) is also an important cause of death in people with intellectual disabilities. ^{517   224}

However, in this group, the mortality rate is not falling in the same way as in the general population (see above). ²²⁵

Risk factors for cardiovascular disease, including coronary heart disease, are common in this group.

Dutch surveys of older people (> 50 years) with intellectual disabilities have shown that the consumption of fruit and vegetables, and exercise, are inadequate in almost the entire population. ^{226   519   520   521}
The risk factors of overweight, diabetes, high blood pressure and high cholesterol are also common. ^{226   522   523}

In addition, people with intellectual disabilities often take medication to manage their behaviour and it has been proven that some of these drugs significantly increase the risk of heart attack.  ⁵¹⁷

People with milder intellectual disabilities who live more independently and are in a position to make more decisions of their own about groceries and cooking are exposed to more risk factors for cardiovascular disease than people who are less independent. ^{226   522   523}

Despite the high prevalence of risk factors for cardiovascular disease (including overweight and elevated cholesterol), the incidence of cardiovascular disease is surprisingly low in people with Down syndrome. ²²⁷

Arteriosclerosis is thought to be less frequent in this group due to low blood pressure, less smoking, protection associated with the additional chromosome 21 and, possibly, the beneficial effect of thyroxine as a treatment for hypothyroidism.

In addition to the risk factors listed here, cardiovascular disease is associated with epilepsy ²²⁸ and sleep disorders. ²²⁹