(December 2, 2008 - Insidermedicine) On a recent trip to Boston, we caught up with Dr. Sekar Kathiresan, MD, who is an Assistant Professor at Harvard Medical School, and the Director of Preventive Cardiology at the Mass General Hospital Heart Center. Dr. Kathiresan's clinical focus is on primary prevention of myocardial infarction (MI) in individuals with a family history of heart attack and his research focus is on finding genes that put people at risk for heart attack.
If I had a family history of heart disease…
If I had a history of family heart disease, I would start by assessing risk factors for heart disease. An individual with family history has about a two-fold increase risk of having a heart attack compared to those who don’t have a family history, and specifically risk factors cluster in individuals with a family history. The risk factors that cluster are things like high cholesterol, or risk for diabetes, or risk for blood pressure. It is very important to have screening for these risk factors if you have a family history, and the screening should start very early. The recommendation for cholesterol screening in adults is starting at the age of 20, and at least once every five years. If the cholesterol level is abnormal on that initial measurement, then it should be yearly (there is a separate set of guidelines for children; this is for adults). Screening for cholesterol should be done, but also for risk factors like high blood pressure and diabetes risk because all of those things go together when you have a family history of heart attack.
Whom should I see to be screened for heart disease?
Typically, the screening can be done by a primary care physician or a family doctor. If there are abnormalities, there are specialty clinics that are often supervised by cardiologists or endocrinologists. I, myself, for example, direct a specific clinic focused on patients with a family history where we do risk factor screening and additional testing that might be necessary to assess risk and then make a set of recommendations to reduce the risk, because it is not just important to assess risk, but of course to do something about it, if you find that there are risk factors. Doing something about it could involve either lifestyle changes, with/without medication.
Are most patients referred from a family doctor?
Many patients are referred to our specialty clinic by a family doctor, but a good number now self-refer based on knowledge from the internet or other places where they may find out about our program. We specifically assess risk based on three dimensions, one is what is what are called ‘traditional risk factors’, and these are things shown over the years to predict risk for heart attack, and they include diabetes, blood pressure, cholesterol, smoking, and a family history. There is a second domain which is blood tests, and these are called blood biomarkers. These are things in the blood which can measure risk for heart attack. The third domain which we assess, in some patients, only as needed, is specialized testing like a CT scan or an exercise treadmill test, so these are typically imaging tests that might give additional information, but again this is only done in people that merit such investigation. Lastly, genetic markers may, in the coming years, become a part of this set of factors to assess risk.
Based on that set of factors, we assess somebody’s risk, and specifically derive a quantitative estimate of their risk of having a heart attack or dying from heart disease in the subsequent ten years, and based on that risk profile the recommendations flow.
What diagnostic tests might be recommended?
The specific tests that we do, in terms of blood tests, are cholesterol panel, a glucose check, and a blood c-reactive protein level. In some patients we will do some additional specialized lipoprotein testing called lipoprotein(a) or lipoprotein particle concentrations measured by nuclear magnetic resonance. These are some of the blood tests, but this all starts with measuring someone’s blood pressure, asking them about their risk for diabetes, asking about their smoking history, etc.
What is the management for patients who are at risk?
Based on the testing that’s done, we can derive a quantitative risk assessment. The quantitative risk assessment can break people down into three risk categories; low risk, intermediate risk, or high risk: Low risk is less than 10% risk of having a heart attack or dying from heart disease in the subsequent 10 years. Intermediate risk is 10-20%, and high risk is greater than 20%. The specific cholesterol goals for an individual vary based on that risk estimate. For those who are greater than 20%, typically the goal is somewhere between 70-100 mg/dl of LDL cholesterol, those who are of intermediary risk ranging from 100-130 mg/dl, and those who are low risk can tolerate up to 160 mg/dl.