Why is this study important?
The majority of heart attacks or strokes occur in people who are considered low or medium risk for cardiovascular disease. Since they are low or medium risk, they would not receive intensive preventive care. More and more preventive care options are available. These range from lifestyle issues, such as weight loss and exercise, to drug therapy. The pharmaceutical options include over-the-counter treatments, such as low-dose aspirin, and a broad range of prescription drugs, which range from low cost statins (oral drugs that reduce lipid levels) to expensive new injectable treatments. One way to summarize the issue is: that we have many options but do not know who needs what.
Certain lipids in blood, best known as LDL-cholesterol (LDL-C) or “the bad” cholesterol, play a critical role in the development of plaques in your vessel wall, known as atherosclerosis. Preventing atherosclerosis or slowing down its progression means lowering LDL-C. In 1978, a product named Mevacor (lovastatin) was launched, followed by a number of related drugs known as “statins”. Lipitor (atorvastatin) was the best-known member of this drug class. These highly effective statins are now generic and the cost has fallen to as low as $0.15/day. In 2015, the FDA approved a new class of injectable drugs that would allow LDL to be reduced even more. These drugs are known as PCSK9 inhibitors. In combination with a statin, they can reduce LDL to levels previously not imagined possible. Injectable PCSK9 inhibitors are expensive and may cost close to $40/day. In other words, the treatments are there, but we now need to improve in deciding who needs what treatment and when to start.
What About Risk Factors?
Until now, reducing the risk of heart disease has been done by looking for risk factors and trying to reduce them. The most famous risk algorithm is called the Framingham Risk Score. It estimates the risk of getting a heart attack in 10 years. The algorithm uses age, gender, whether you are a smoker, your LDL-C (bad cholesterol), HDL-C (good cholesterol), your blood pressure (systolic BP), and whether you are on blood pressure medication. The most important risk factors are age and gender, neither of which can be changed. So that leaves smoking, blood lipids, and blood pressure. Risk factors contribute to getting plaque disease and plaque disease exposes the person to risk. Instead of relying on risk factors, it is better to look for early plaque disease – getting one step closer to the problem. This is what our effort is for. Our goal is to develop a safe and economic way to look for and score plaque in the major blood vessels. This, in combination with risk factors, offers a better way to find those at the highest risk. Once we identify a person with more plaque than is normal for his or her age, intensive preventive measures can be started. Time is important and finding people early provides the best result. For example, a 55-year old male with slightly elevated blood pressure and LDL-C levels would normally be considered at medium risk. However, if we find plaque in both carotid arteries, which is very abnormal at his age, this man would receive a much more intensive form of preventive care.
Many people with low or medium risk are having a heart attack or stroke, often with serious and permanent consequences. Our BioImage studies aim to develop a new, safe, and economical method for routine use in finding individuals who have more plaque disease than average for their age. These men and women can then receive intensive preventive measures, which, in some cases, may involve expensive drugs.