A simple “calcium” scan could screen people for heart disease – decades before symptoms have started, say scientists.
It looks for the build up of tiny amounts of calcium in the arteries which can increase risk of developing the illness years into the future.
This would allow doctors to recommend lifestyle changes – such as improving diet, quitting smoking and doing more exercise – to protect patients.
Called a CAC (coronary artery calcium) scan is quick, painless and non-invasive and looks for white specks or streaks on the x-rays.
Deposits of calcium can build up on artery walls as part of plaques in a process called calcification and is an early sign of heart disease.
It narrows and hardens arteries – eventually leading to blockages that could trigger a heart attack.
Calcification becomes more likely as we age.
The higher the calcium score worked out by a computer programme the more likely heart disease.
A score of zero puts a patient at very low risk – but even one indicates they should be adopting healthier behaviours.
Cardiologist Professor Alan Rozanski, of Mount Sinai St. Lukes Hospital in New York, said: “The CAC scan can detect heart disease even decades before the symptoms of heart disease may first appear.
“Additionally, using current state-of-the-art scanners, CAC scans are associated with only very low radiation exposure, similar to that of a mammogram, and they are less costly than all other types of imaging.
“Given these advantages, there is increasing interest in determining whether the use of CAC scanning could lead to earlier and more effective treatment of heart disease.”
A CAC scan is a type of computed tomography (CT) – a technique that can use images of the heart to show build-up of dangerous coronary plaques which restrict the flow of blood.
The study published in JACC: Cardiovascular Imaging said it’s often referred to as a “calcium scan” and could be particularly useful when screening for coronary artery disease.
People are screened for many types of diseases such as breast, bowel and lung cancer even when no symptoms are present.
But there’s currently no consensus among doctors regarding when to use cardiac imaging to screen for heart disease – which kills more than 73,000 Britons each year.
Instead a patient is typically assessed using a combination of historical data and a standard blood test to measure fat and glucose in the blood to arrive at a risk score.
Increasing data indicates a CAC scan is far more accurate for this purpose.
Research has shown in about 40 to 60 per cent of cases the first time heart disease is discovered is when a heart attack or death occurs.
Prof Rozanski said: “By using imaging for screening we can detect problems early on which gives the patient an opportunity to make lifestyle changes to help avoid developing heart disease – such as by improving nutrition, starting to exercise or quitting smoking.
“We believe this will not only help improve and save lives but that it can ultimately contribute to lower health costs since the earlier adoption of positive health habits can reduce patients clinical risk and potentially eliminate the need for more costly interventions later on.”
In the study his researchers reviewed five clinical trials with 4,615 participants who were not showing signs of heart disease.
One involved cardiac stress imaging, three CAC scanning and another an alternative X-ray technique called non-invasive coronary CT angiography.
Collectively, the trials showed because modern therapies have dramatically reduced the frequencies of heart attacks it may be difficult to prove the use of imaging techniques reduce cardiac deaths in clinical trials.
But in one of the trials – the EISNER – the use of CAC scanning was shown to improve cardiac risk profiles without increasing overall medical costs, but more studies in this area are needed.
Prof Rozanski said: “There is now sufficient evidence to support the routine use of CAC scanning for screening in clinical practice.
“Importantly, the CAC score has become one of our most robust predictors of patient risk.
“Patients are at very low risk when the CAC score is zero and at high risk when the CAC score is highly elevated.
“Any degree of CAC abnormality, however, even a CAC score of one or above, is sufficient reason for patients to adopt more heart-healthy behaviours.”
In the UK about one in six men and one in ten women die from coronary heart disease (CHD).
There are an estimated 2.3 million people living with it and around two million people affected by angina – the most common symptom.