Coronary heart disease (CHD)

Coronary artery disease is a serious disease of the heart in which circulatory problems occur in the coronary arteries. These arteries are also called coronary arteries or coronaries. They are arranged in a ring around the heart muscle and ensure the supply of oxygen and nutrients.

Coronary heart disease includes a feeling of tightness in the chest (angina pectoris) as well as heart attack or sudden cardiac death. The cause of coronary heart disease is arteriosclerosis of the coronary vessels (coronary sclerosis), which is characterised by a build-up of blood fats, blood clots (thrombi) and connective tissue on the inner walls of the vessels. CHD is considered a disease of affluence. Factors that increase the risk of disease are:

• Obesity (and here mainly abdominal fat).
• Diabetes
• High blood pressure
• High blood fat levels
• Little exercise
• Smoking

Coronary heart disease has been the number one cause of death in Germany for years and is therefore one of the most important widespread diseases. Men are affected earlier and more frequently by CHD than women.

People suffering from coronary heart disease suffer from impaired blood flow to the heart muscle. The reason for this is a narrowing of the coronary vessels as a result of fatty or calcium deposits on the vessel walls (arteriosclerosis).

In coronary heart disease, the heart muscle receives too little blood and thus too little oxygen and nutrients. As a result, there is a disproportion between the oxygen demand and the oxygen supply, which is particularly noticeable under heavy strain. If the diameter of the coronary arteries decreases by half, circulatory problems usually occur as well.

The following risk factors increase the risk of developing coronary heart disease:

• Unhealthy diet: foods rich in fat and high in energy density lead to obesity and high cholesterol levels.
• Obesity: as a result of years of unhealthy eating.
• Lack of exercise: regular exercise leads to lower blood pressure, improved cholesterol levels, and increased insulin sensitivity in muscle cells.
• Male sex: Before menopause, women are at lower risk of developing CHD due to protection provided by female sex hormones.
• Genetic predisposition: Since there is an increased incidence of cardiovascular disease in some families, it can be assumed that genes play a role.
• Smoking: Substances contained in tobacco smoke (cigarettes, cigars, pipes) favour the formation of unstable deposits (plaques) in the vessels, which can pose a risk.
• Increased blood pressure (hypertension): hypertension directly causes damage to the inner walls of the blood vessels.
• Elevated cholesterol: Elevated LDL levels and low HDL levels promote plaque formation.
• Diabetes mellitus: If diabetes mellitus is poorly controlled, high blood sugar levels occur, which in turn damage the vessels.
• Age: An increase in the incidence of the disease can be observed in men from the age of 45 and in women from the age of 50.

The symptoms of CHD depend on the degree of narrowing of the coronary arteries and the location of the narrowing. Minimal narrowing is asymptomatic in many cases, but severe narrowing often causes symptoms.

• Chest pain: Coronary artery disease is often manifested by chest pain or a feeling of tightness in the chest (angina pectoris). This is especially true when there is an increased need for oxygen, i.e. during physical or mental stress. The pain of angina pectoris often radiates into the left arm, but in some cases also into the neck, throat, back, jaw or upper abdomen.
• Acute heart attack: Symptoms of an acute heart attack include shortness of breath, sweating, nausea and fear of death.
• Cardiac arrhythmias: In many people, cardiac arrhythmias represent the first sign of CHD.
• Diabetics often without symptoms: Some people, mainly diabetics, often have no symptoms. If this is the case, it is called silent ischemia (lack of blood flow). It may be that the heart nerves are so damaged as a result of diabetes that they can no longer transmit pain signals (diabetic neuropathy). The damage to the heart muscle therefore occurs unnoticed.

To diagnose coronary heart disease, the doctor first asks about the nature of the symptoms. Of particular interest are the type, duration and severity of the symptoms and when they occur. The medical history (anamnesis) and a physical examination further indicate the disease, as there are a variety of diseases that have chest pain or shortness of breath as symptoms.

In addition, a blood test will allow the doctor to determine other possible risk factors for coronary artery disease, such as high blood cholesterol or blood sugar levels. In addition, the blood pressure is measured, questions are asked about how often one smokes, how one eats and how often one exercises.

These technical examinations are also helpful in the diagnosis:

• The basic examination is the resting ECG. If, after the examination, a valvular defect or cardiac insufficiency is suspected, a cardiac ultrasound (cardiac echo) is performed.
• If, after the examinations, there is a suspicion of narrowing of the coronary arteries, the doctor will arrange for an exercise ECG. In this type of examination, the heart is either artificially stressed by medication or the patient attempts to ride a bicycle while lying down. In addition to stress echocardiography, myocardial scintigraphy and special magnetic resonance imaging (MRI) of the heart are alternatives that also reveal the blood flow to the heart muscle.
• If a stress test is considered too dangerous for the patient, for example because the resting ECG has already shown typical changes, a cardiac catheter examination is often carried out directly. This examination is also carried out if the stress test has shown indications of a CHD.
• If there is a suspicion of an acute coronary syndrome, for example a heart attack, an ECG and special blood tests (cardiac troponin) are carried out immediately. Acute coronary syndrome refers to various phases of acute circulatory disorders of the coronary vessels, which can be life-threatening.
• In order to exclude other diseases, in some cases an X-ray examination of the chest is also performed.
• As a further examination method, coronary angiography can be performed, which makes the coronary vessels visible.

Coronary heart disease cannot be cured. Therefore, the therapy aims to improve the quality of life of those affected and to prevent a progression of the disease. Normally, the symptoms, such as angina pectoris, are easily treatable and secondary symptoms, such as a heart attack, are therefore avoidable. Thanks to optimal treatment, those affected usually have the same quality of life and life expectancy as healthy people.

Often there can also be psychological side effects, such as depression, which have a negative impact on the disease. For this reason, therapy also attempts to treat the accompanying psychological symptoms.

Medications:

Medications range from those that both relieve the symptoms of CHD (such as angina attacks) and prevent complications and increase life expectancy.

• Medications that lead to improved prognosis and prevent heart attacks include

Anticoagulants:

Antiplatelet drugs (blood thinners) stop the deposition of platelets and thus prevent blood clots (thromboses). Acetylsalicylic acid (ASA) is usually used as the active ingredient.

The most common side effects include hypersensitivity to the active substance, an increased risk of stomach ulcers and bleeding, and asthma attacks may occur more frequently in asthmatics. If there is intolerance, the active ingredient clopidogrel can be used.

Beta-blockers:

Beta-blockers have the effect of lowering blood pressure. They slow down the heartbeat, reduce the oxygen demand of the heart and thus lead to a relief of the heart. After a heart attack or in CHD with heart failure, beta blockers have been shown to reduce the risk of death. Beta-blockers can also be beneficial for hypertensive patients.

The main side effects include: Headache, dry mouth, dizziness, slow pulse rate, low blood pressure, sleep disturbances with nightmares, cardiac arrhythmias. Asthmatics may experience clustered asthma attacks.

Cholesterol-lowering drugs:

Statins have the effect of lowering cholesterol levels, leading to a slower progression of atherosclerosis. Patients who have normal blood lipid levels also benefit from taking them.

The main side effects are constipation, bloating, nausea, muscle pain, rash in combination with itching. Special care should be taken when statins are taken with other blood lipid-lowering agents (for example, fibrates or nicotinic acid derivatives). In this case, severe side effects may occur.

• Medications that fight the symptoms of CHD.

Nitrates:

Nitrates cause the blood vessels of the heart to dilate, resulting in an improved oxygen supply. In addition, the blood vessels throughout the body dilate. Because of this, blood flows back to the heart more slowly. As a result, the heart does not have to pump as much and requires less oxygen.

The effectiveness of nitrates is particularly rapid, which is why they are preferred as emergency medication for acute angina pectoris attacks.

Special care should be taken to ensure that nitrates are never used in combination with drugs for impotence (phosphodiesterase-5 inhibitors). If this nevertheless occurs, it can lead to a life-threatening drop in blood pressure.

The best-known side effects are headache, flushing, reddening of the skin, nausea and vomiting, severe drop in blood pressure, skin rash with itching.

• Other treatment options

ACE inhibitors:

ACE inhibitors cause relief of the heart by dilating blood vessels and lowering blood pressure. Patients suffering from heart failure or hypertension have a better prognosis by taking ACE inhibitors.

Irritable cough is known to be the most common side effect.

Angiotensin I blockers:

They are mainly used when there is intolerance to ACE inhibitors.

Side effects that may occur include headache, fatigue, abdominal pain, nausea and diarrhea, dizziness, cough.

Calcium channel blockers:

Also like ACE- inhibitors, they cause the blood vessels to dilate, lowering blood pressure and thus relieving the heart.

If the patient cannot tolerate beta blockers, calcium channel blockers should be given as a second choice. Side effects include headache, severe drop in blood pressure, water retention in the ankle area (edema), cardiac arrhythmias, skin rash with itching.

Catheters and surgery:

If medication does not achieve the desired effect and the symptoms persist, a dilatation of the coronary arteries (PTCA) or bypass surgery may also be considered. To prevent the dilated area from narrowing again, a stent is inserted.

These methods should also be used if several coronary vessels are affected or if the narrowing is located at the beginning of a large vessel. Which method is used depends on the individual. However, the main factors are the findings, concomitant diseases and age.

Lifestyle also plays an important role in the success of the therapy. Factors that counteract a worsening of the CHD are:

• Quitting smoking
• If you are heavily overweight, you should try to lose weight. Even a few kilos have a positive effect.
• A healthy diet is essential. This should include lots of fresh fruit and vegetables, plenty of fish, little meat, and olive oil as the main source of fat (Mediterranean diet).
• Regular exercise is advisable. The ideal is at least 15 minutes of moderate exercise three to seven times a week. It does not matter whether jogging, swimming or cycling is chosen. If there is a lack of time, a brisk walk can also be a substitute.
• The prescribed medication must be taken regularly, even if one feels in good health.
• There should be an annual flu shot. Pneumococcal vaccination should be given every five years.

Patients suffering from CHD should keep regular check-ups with the doctor (quarterly to half-yearly).

If high blood cholesterol levels are diagnosed, these values should also be checked regularly.

The prognosis of CHD depends on the number of constrictions in the coronary vessels and where they are located. It also depends on the stage of the disease and how far it has progressed.

The following factors are important:

• Concomitant diseases, such as high blood pressure, diabetes, chronic liver disease, arterial circulatory disorders in other organs (brain, kidney, legs), chronic obstructive pulmonary disease, chronic inflammatory diseases, cardiac muscle weakness, and malignant tumors
• Extent of the symptoms in the case of angina pectoris
• Heart attack or previous severe angina pectoris attacks
• Age and sex
• Mood and state of health: Lonely living situation, depressive mood and withdrawal from normal life have a negative effect

Usually, the symptoms can be improved with the help of medication and, if necessary, by removing the constriction. If CHD is treated well, most sufferers can lead a life free of symptoms similar to that of healthy people.

Improvement over time also depends on lifestyle and whether it has been changed. This includes abstaining from nicotine, plenty of exercise, avoidance of excessive weight and a balanced diet. In addition, the prescribed intake of medication and the control examinations in the prescribed intervals.

If the disease is only diagnosed at a late stage or if it is not treated adequately, heart failure can sometimes develop, leading to a worsening of the prognosis.

The best methods to counteract CHD have already been mentioned several times in the text. A heart-healthy lifestyle is essential, which includes quitting smoking, maintaining a healthy weight, exercise, and screening.