While medications have clearly had an impact in reducing death in patients with known cardiac disease, the question remains how do we treat people with borderline risk factors and no history of heart disease.  In preventing heart attacks the disease we are treating is arteriosclerosis of the coronary arteries. In recent years there have been a number of advances in lab testing that give us greater insight to the underlying biochemistry of cholesterol metabolism and help us access risk. These include VAP testing, NMR testing, cardiac CRP etc. Unfortunately while they help us better access risk they do not tell us if arteriosclerosis is present in the coronary arteries. With arteriosclerosis we have both hard and soft plaque. The hard plaque is calcified but it is the soft plaque that is of concern as this can rupture forming a site for a blood clot to develop which can then block the artery and cause a heart attack. The general school of thought is that we are at significant risk for this happening when we have a 70% blockage or greater in one of our coronary arteries.I recently met with Dr. Mark Baganz and Dr. Anthony Lloyd of Chesapeake MRI to discuss some of the newer cardiac imaging technologies and how they might impact on our decision making.

 

Cardiac calcium scoring is a great tool for looking at calcifications in the coronary arteries. Calcifications are indicative of hard plaque.  The technology was originally developed in the late 1990's by Dr. Arthur Agatstan of South Beach Diet Fame. At this time it was experimental. By 2002 with the improvements in CAT scanning it became widely available. As we discussed previously it is soft plaque that we generally worry about, not hard plaque and this had been the knock against this technology. However "wolves travel in packs" and where there is hard plaque there is soft plaque. One can generally grade these in three categories ( 0 calcium, mild to moderate calcium, severe calcium)  A calcium score of zero correlates with a very low likelihood of coronary disease. So if one is on the fence about going on a lipid lowering medicine and the calcium score is zero it is hard to make an argument in favor of using a statin drug. Lifestyle management should be the key intervention. However if one has any calcium present they have coronary disease and in my view should be on a statin medication in addition to lifestyle management. If one has a severe calcium score more testing is needed to determine how extensive the disease is. No decision should be made without consultation with your physician.

 

CAT scan angiogram is a newer technology in which an angiogram can be done of the coronary arteries.  This gives wonderful pictures and is able to diagnose both soft and hard plaque. It is very good at picking up lesions of 70% stenosis or greater but may overestimate the severity of lesions less that 70% I looked at some of these pictures and they are amazing. If any of you are "Oprah"fans this is the technology Dr. Oz has demonstrated on the T.V. show. The radiation exposure from this is minimal and the major risk is if you are allergic to dye or have underlying kidney disease. However the dye loads and radiation exposure are significantly less than a conventional angiogram. We have found this technology to be useful in patients who have a negative stress thallium or stress echo but we still think there may be significant heart disease or in patients we think may have a false positive stress thallium. Both stress thallium and stress echo's will miss about 5-10 % of people with significant coronary disease. It is still unclear how the use of this technology fits in the current medical mainstream.  However it is my belief that in the future this will become one of the dominant tools in diagnostic cardiology especially as the imaging quality of CAT scans gets better and better.