Coronary artery disease (CAD), the leading cause of death for men and women worldwide, is the accumulation of plaque within the walls of the arteries which supply the heart with oxygen and nutrients. Hard plaque is the buildup of calcium, fats and abnormal inflammatory cells within the walls of the arteries. Over time, this plaque can harden which can lead to narrowing of the artery wall (called stenosis).
Normally, the coronary arteries do not contain calcium; therefore, a standard measurement of CAD is the Calcium Score test. However, soft plaque does not contain calcium and has been dubbed the silent killer as it is “hidden” inside the artery walls and can cause sudden death if it ruptures. Soft plaque rupture is responsible for up to 75% of acute coronary events.
The good news is that advanced imaging can identify soft plaque. Over the past 15 years, advances in imaging technology have given clinicians a non-invasive way to evaluate the coronary arteries using Computed Tomography (CT). The Coronary Calcium Score and the Coronary CT Angiogram are both CT exams, so let’s take a look at their individual use.
Coronary Calcium Score
Coronary Calcium Score is a test to measure the presence and amount of calcification in the walls of the coronary arteries. This exam will identify the location and the amount of calcified plaque in a particular coronary artery. It will not identify the areas of arteries that may have blockages, but it can be used to determine if a patient has CAD and to estimate its severity. This exam is most beneficial for people with an intermediate risk of CAD. Physicians use the Calcium Score to determine follow-up testing and behavior modification, if necessary. This exam should not be used for people with a low or high risk of CAD, or those who are experiencing chest pain, as it does not show soft plaque or areas of blockage.
Coronary CT Angiogram
This exam is a more detailed look at the coronary arteries as well as the chambers and valves of the heart. It can also identify areas of blockage. A contrast agent is administered which fills the coronary arteries and identifies plaque, both hard and soft. This exam is helpful in assessing a wide range of heart conditions, including coronary artery disease, diseases of the aorta and other structural heart problems. This exam is appropriate for people who have multiple risk factors, are experiencing chest pain, or have had an inconclusive stress test. It may also be used to see if stents are open or if coronary bypass grafts are functioning normally. This test is often performed for screening patients prior to non-cardiac surgeries. A normal result from this study means there is a 99% assurance that there is no coronary artery disease.
Risk factors for developing CAD include family history of heart disease; men over the age of 40 and postmenopausal women; high blood pressure; high cholesterol; smoking; obesity; diabetes; and physical inactivity. A healthy lifestyle can help alleviate your chances of developing coronary artery disease.
