Calcification is only one aspect of coronary artery disease. It is rarely the only condition a physician considers for a patient with potential heart problems. However, the role of calcium in atherosclerosis has inspired researchers to develop tests to measure the amount of calcium in the arteries. The idea is to measure how much plaque is present in the arteries by how much calcium is present. However, because calcium is not always involved in atherosclerosis, these tests have limitations. In addition, these tests are still being refined, so it remains difficult to accurately and consistently measure arterial plaque without more invasive testing, such as a coronary angiogram. Nevertheless, some tests can provide useful information, even when they have been developed to identify other problems, and they are relatively inexpensive and quick. These tests include:  

• Ultrafast computed tomography (ultrafast CT or electron beam computed tomography [EBCT]) scans. These noninvasive imaging tests take multiple views of the heart and measure the calcium in the arteries. The results of this test can be expressed in several ways, including an Agatston score (the most common), calcium volume score or calcium mass score. This test can sometimes identify atherosclerotic heart disease before symptoms become apparent because it can detect growing plaque lesions before they begin to narrow the artery, thus restricting the flow of blood.
  
  Studies have shown that coronary artery calcification (CAC) scores are positively correlated with the degree of atherosclerosis, and that a complete lack of CAC is highly associated with a lack of atherosclerosis. Thus, patients with elevated CAC scores are likely at increased risk of heart attack caused by coronary artery disease, even if symptoms aren't present. This test may also be of value in an emergency room setting. Studies indicate that the CAC score can help physicians quickly determine which patients require further cardiac testing and which patients are not suffering from cardiac-related conditions. 
  
  

  It is important to note that CT "calcium score" testing is currently being promoted by alternative health practitioners in out-patient settings, often without a physician's referral. These tests can provide valuable information, and may be of some value in predicting future risk for heart attack, especially when combined with other markers of cardiac risk such as the Framingham coronary risk profile and inflammation as measured by a C-reactive protein test. However, treatment decisions are rarely based on CAC scores alone. If an elective CT score finds an elevated CAC score, patients are urged to take these results to a cardiologist for further testing and evaluation, if warranted. A cardiologist will likely assess for symptoms and signs of heart disease, perform an EKG, and order a stress test or CT angiogram. 

  The following Agatston CAC scores are used to classify the degree of calcification:

• • 0 - no artery disease

  • 1 to 99 - mild coronary artery disease

  • 100 to 399 - moderate coronary artery disease

  • over 400 - severe coronary artery disease

Hoping to clarify the situation, the American College of Cardiology Foundation and the American Heart Association in 2007 issued recommendations for the use of CAC scoring. These included:

• Asymptomatic patients with intermediate risk, according to the Framingham criteria, may consider CAC scoring, which sometimes results in risk reclassification.
  
  
• CAC scoring is not recommended for patients in the low risk category, according to the Framingham criteria. As a result, population-wide screening of low-risk people is not recommended.
  
  
• CAC is not recommended for patients in the high risk category because they are likely already being intensively treated and there is no evidence that CAC scoring will change their treatment plan.
  
  
• In patients who have a high CAC score, of more than 400, additional testing is not recommended because, among patients in the high risk category, intensive therapy is already recommended, and among patients in the low risk category, a negative exercise test would confirm the low likelihood of disease.

Beyond coronary artery disease, researchers are continuing to uncover new applications for CT scanning. For instance, CAC scores may also be helpful in differentiating between various kinds of cardiomyopathies. In addition, multiple CAC tests may be able to help monitor the progress of coronary artery disease or the effectiveness of medication, although more studies are needed.

• Dental x-rays. New panoramic dental x-rays have been reported to reveal arterial calcification in the carotid artery, which supplies most of the blood to the head and neck. Panoramic dental x-rays are less expensive than some other methods and expose patients to less radiation. Further research is needed to determine whether they will become a routine screening tool. 
  

• Mammograms. These tests screen for the presence of breast cancer and studies suggest that they may help to detect calcification within the breast artery. The technology behind these tests continues to evolve, and may one day offer routine screening for calcification in this area of the body.

It is important to point out that physicians are not currently using these tests to diagnose heart disease or, in most cases, recommend a course of action. Rather, the presence of calcium as indicated by one of these tests may prompt the physician to recommend more thorough testing, including nuclear stress test and cardiac catheterization.

In the future, as the understanding of atherosclerosis improves and the tests become more sensitive, their role may expand to include:

• Routine screening (such as an annual physical).
  
  
• Patients who experience episodes of chest pain despite a normal nuclear stress test. The ultrafast CT is already used for this in some cases.
  
  
• Patients who have a number of risk factors but no symptoms. The ultrafast CT is already used for this in some cases.
  
  
• Patients whose progress needs to be monitored to determine whether treatment is successfully reducing built-up plaque. Treatment may include lifestyle changes such as an increased level of exercise or taking cholesterol-reducing drugs such as statins. The ultrafast CT is already used for this in some cases.