Heart Screening

Heart disease and diseases of the circulatory system are the leading cause of death in the UK, with one third of all deaths occurring from cardiovascular disease. Heart disease is the largest cause of death within this group, mostly due to myocardial infarction (heart attack), which is caused by the rupture of a fatty plaque within a coronary artery followed by clot (thrombus) formation which blocks the artery, starving the heart muscle of blood and oxygen. It carries a high mortality, with 50% of heart attack patients dying within 28 days, and 75% of these deaths occurring within the first 24 hours.

The cost to the UK health care system is vast, estimated at £14.4 billion in 2006; in the same year production losses due to death and illness associated with cardiovascular disease cost the UK over £8.2 billion.

There are frequently no warning signs that a patient has cardiovascular disease, and a heart attack may be the first symptom and occur completely out of the blue. There are, however, several risk factors which predispose to heart disease, such as:

• Smoking
• High cholesterol
• Diabetes
• High blood pressure
• Obesity
• Lack of exercise
• High alcohol intake
• Excessive mental stress

Many of these can be modified by changes in lifestyle (for example, by eating more healthily, maintaining an ideal body weight, exercising and giving up smoking) and, if necessary, medication (statins to lower cholesterol and drugs to lower blood pressure, for example). Most of these risk factors can be readily identified by a doctor undertaking a thorough medical history and examination, together with a simple fasting blood test. This information helps to determine the likelihood that a patient will develop heart or other cardiovascular disease in years to come, and so to what extent the various risk factors could and should be modified. Unfortunately this approach will fail to identify a significant number of patients at risk of heart disease, and likewise it will also misclassify a proportion of patients as “at risk” when in fact they are not.

With more modern non-invasive techniques it is now possible to look for the very beginnings of coronary artery disease and carotid artery disease with simple tests such as the coronary artery calcium score and carotid artery intima media thickness assessment.  This has taken screening to a more detailed and personal level such that a patient’s risk can be far more accurately defined and treatment individualised rather than inferred from population statistics which will of course carry an inherent inaccuracy.      

Screening is not just undertaken to look for coronary artery disease, but in certain circumstances may also be used to look for a number of other cardiac conditions. For example, if one family member is born with a heart abnormality (known as congenital heart disease) or is found to have a heart muscle abnormality known as a cardiomyopathy, there is a risk that other family members may be similarly affected. Screening for such conditions will usually involve an ECG and some form of imaging, such as echocardiography in the first instance, with a view to more sophisticated investigations such as 24 hour Holter monitoring and cardiac MRI (CMR), or even genetic testing, as necessary.