Coronary artery disease (CAD, also called coronary heart disease, or CHD) is caused by the narrowing of arteries that supply the heart with oxygen. The symptoms can vary greatly, depending on how long the arteries have been narrowed and how constricted they are. It can lead to complications such as heart failure and heart rhythm problems. If a coronary artery suddenly becomes completely blocked, it can result in a heart attack.
CAD symptoms can range from breathlessness to chest pain of varying degrees. This kind of pain is called angina. Angina is usually associated with chest tightness or fear, and it may extend into the arms, back of the neck, back, upper abdomen or jaw.
Stable angina means that the pain is usually caused by physical activity, and goes away quickly. Sudden chest pain that starts when someone is at rest and not engaged in any physical activity is called “unstable angina” or “acute coronary syndrome.” Unlike stable angina, this is an emergency: there is a risk of heart attack because the artery may become fully blocked without any warning.
CAD is caused by arteriosclerosis. Arteriosclerosis develops from minor inflammations in the walls of blood vessels. Cells, fats and other substances stick to the walls there and form deposits called plaques. When they are just developing they are not very noticeable.
If these plaques build up too much inside of a coronary artery, they may start affecting the flow of blood though the blood vessel more and more, and keep part of the heart muscle from getting enough oxygen. Physical activity or emotional stress can then lead to discomfort and pain in the chest (stable angina).
But it is also possible for these deposits to suddenly break off and form a blood clot that blocks the blood vessel almost entirely. If this happens, chest pain can occur without any previous physical strain (unstable angina). If one of the arteries is blocked completely (infarct), part of the heart muscle will die if no immediate action is taken.
The risk of developing CAD and possible complications varies greatly from person to person. One group of risk factors includes age and sex. These are factors that cannot be changed. The other group includes factors that are influenced by your lifestyle and environment, such as smoking, being overweight, and high cholesterol or blood pressure levels. Also, other diseases like diabetes can increase your risk of CAD.
There are no exact figures available for how many people in Germany have CAD, but there are estimates of the number of heart attacks: Each year about 1 to 2 out of 100 women between the ages of 25 and 74 have a heart attack. This risk is higher for men of the same age group: about 4 out of 100 men have a heart attack each year.
CAD is typically a chronic disease. Someone may first notice that they have it after experiencing angina symptoms, but CAD can also cause a heart attack without any previous symptoms. In some cases even the heart attack itself goes unnoticed: this is called a silent heart attack. People who have nerve damage due to diabetes, for example, might not feel the typical symptoms of a heart attack.
The severity of angina can vary, regardless of how much the supply of oxygen to the heart muscle has been affected. There are four grades of severity:
|Grade||Severity of symptoms|
Chest pain only in response to sudden physical or emotional strain, but not during basic everyday activities like walking or climbing stairs
Chest pain during more intense activities like walking quickly, walking uphill and climbing stairs after eating, when it is cold or when also emotionally stressed
Chest pain even during low-intensity physical exertion like walking or getting dressed
Chest pain when at rest or during slightest physical exertion
Chest pain is often caused by CAD, but it may have any number of other causes, such as a heart muscle inflammation, or diseases affecting the lungs or food pipe (esophagus). So further testing may be needed to diagnose CAD with any certainty.
The most important is an electrocardiogram (ECG, or EKG). This test is done either while you are resting or while you are exercising. It is also possible to do an ultrasound scan of the heart (echocardiography) or use another imaging technique to examine the heart. Age, existing conditions, and the type of symptoms will determine what additional testing might be needed in any individual case.
To get an idea of the risk of complications and make a treatment plan, your doctor may suggest having more tests. Standard diagnostic testing includes:
- Medical history: Your doctor will ask you about the type, duration and severity of your symptoms, about cardiovascular disease in your family, and about your lifestyle – whether you smoke, are physically active, or what your diet is like. These answers will help to get a better idea of your risk of complications.
- Blood pressure: Blood pressure is measured because high blood pressure is a key risk factor for complications of CAD.
- Physical exam: Tests such as listening to the heart or feeling the liver can help find out whether you might have other conditions such as heart failure or heart valve problems.
- Test for metabolic disorders: Your blood might be tested to look for metabolic disorders such as type 2 diabetes. Type 2 diabetes can greatly increase the risk of developing complications.
In Germany, people covered by statutory health insurance are entitled to a general health check-up every two years from the age of 35 onwards. The aim of this check-up is to detect early signs of cardiovascular disease, diabetes and kidney problems. It involves things like having your blood pressure taken, and blood and urine tests.
Treatment of CAD has two aims. The first is to reduce the symptoms and disruptions to everyday life caused by angina to a minimum. This will include general steps like changing your diet, getting more exercise, or quitting smoking. Medication is typically used to help relieve the symptoms too. Cardiac catheterization is often used to widen a narrowed coronary artery if the symptoms are persistent and severe. If there are many narrowed passages, or if several blood vessels are affected, bypass surgery may be an option. As the name implies, a bypass allows the flow of blood to be redirected around the narrowed artery.
The second goal is to prevent complications of CAD, such as a heart attack or heart failure.
People who have CAD can participate in cardiac rehabilitation. This aims to increase physical endurance, improve quality of life, and prevent complications.
Different cardiac rehabilitation programs may involve doing different things. They are often a combination of exercise, learning how to deal with the disease and risk factors, as well as psychological support. Rehabilitation is directed by a team of specialists from the fields of medicine, physiotherapy, nutritional sciences and psychotherapy. Research has shown that cardiac rehabilitation that includes exercise as one component is worth doing: it can improve quality of life and increase life expectancy.
Cardiac rehabilitation is strongly recommended when someone has had a heart attack, when CAD has already led to heart failure, or when symptoms are severely affecting normal everyday activities. Your doctor can help you submit an application for cardiac rehabilitation to the appropriate payer. In Germany this will typically be a statutory health insurer or pension fund.
Some people who have CAD may feel guilty because they think they should have done more for their health. But individual lifestyle is just one of several factors that influence your overall risk. It can also be difficult to change basic habits once you've been diagnosed. It can sometimes help to make changes step by step.
Anyone with CAD who has statutory health insurance in Germany can participate in a structured disease management program (DMP). These programs are meant to improve the quality of life of people who choose to be part of a DMP, and to help lower their risk of complications.
The best way to sign up for a DMP is to contact your health insurer.
Bundesärztekammer (BÄK), Kassenärztliche Bundesvereinigung (KBV), Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF). Nationale Versorgungsleitlinie Chronische KHK – Langfassung. Version 1.13. July 2012
Anderson L, Thompson DR, Oldridge N, Zwisler AD, Rees K et al. Exercise-based cardiac rehabilitation for coronary heart disease. Cochrane Database Sys Rev 2016; (1): CD001800.
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