I’m continuing a discussion about tools for the early diagnosis of cardiovascular disease so that more specific and beneficial preventive measures can be initiated. Previously, I discussed the use of ultrasound to view the carotid arteries looking for vessel wall thickness and soft plaque. Today, I turn to the “coronary calcium score” which can be complementary to the cIMT or can stand alone. Coronary calcium scoring (CAC) involves a rapid CT scan which looks for calcified plaque in the heart arteries. The calcium score has been shown in excellent studies to correlate closely with the risk for future heart attack and has been found to make a significant difference in standard risk calculation.
The scoring is as follows:
- 0 – no calcium, very minimal 10 year risk.
- <100 low risk.
- 100-400 – moderate risk.
- >400 – high risk.
- >1000 – very high risk.
This test carries minimal radiation exposure (equal to 2 mammograms) and costs $100 or less. You have to go to a radiology outpatient center and put on a gown, but the test itself takes less than 5 minutes. For the last few years, CAC has been our go to diagnostic test at Trinity and has served us well. We have found both unexpected heart disease in “low risk” patients and clear arteries in “high risk” patients giving either a wake up call or reassurance. A proposed protocol for the two tests is to use the cIMT initially as it shows soft plaque which is the most vulnerable to rupture causing heart attack or stroke. It can also be followed for improvement. If the cIMT is abnormal we can assume that the CAC is abnormal. If it is normal and other risk factors are high, it is reasonable to order a CAC so that significant disease is not missed. We will work out the best protocol over time. Bottom line: I am more confident than ever in being able to accurately diagnose arterial disease before symptoms occur. This increases our ability to prevent heart attack and stroke and allows us to leave off medicines when not needed. Will discuss biomarkers and lipoproteins in coming posts.