By Hawthorne Haywood
Many people think of the heart as an extremely delicate and complex organ. Yet Dr. John William McEvoy (Bill), a cardiologist at the Johns Hopkins University School of Medicine, explains that the heart is a fairly straight-forward pump.
To learn more about how this pump functions and overall heart health, we sat down with Dr. McEvoy and discussed common myths about the heart, heart disease preventive care, and new guidelines produced by the American Heart Association. Dr. McEvoy graduated from the National University of Ireland, UCC School of Medicine in 2004. In 2008, Dr. McEvoy joined Hopkins’ residency program, and in 2011, as a fellow, completed training in cardiac prevention, cardiac imaging, and cardiac epidemiology at Johns Hopkins. Currently, Dr. McEvoy is an assistant professor of medicine in the division of cardiology
at Johns Hopkins.
What inspired you to become a cardiologist?
As a medical student, I was always inspired by the cardiologists I worked with. Cardiologists were some of the most passionate doctors with whom I worked, not only in Ireland but also when I came to the U.S.
I find cardiology to be one of the most exciting and dynamic of all the medical fields. The field is the fastest growing in terms of new technologies, devices and drugs. There is always new science and developments.
When a patient is sick with cardiovascular disease, you can do a lot very quickly to improve their health. That’s very tangible feedback. You can see a patient getting better, and it’s rewarding in that aspect.
What are some common myths about the heart?
People think the heart is very complicated, like it is a delicate organ. It is to a point, but it is not that complicated. It is simply a pump. Without a pump or battery, the body is not going to work. It is reasonably simple to understand what to do when there is heart failure.
A common myth that is important for public health is that men have a higher risk of cardiovascular disease (CVD) than woman. That is overrated or over advertised. In fact, women have just as high a risk of CVD as men do. Men just tend to present symptoms earlier and women don’t present in the typical way men do. Women can have just as many problems as men. Cardiologist are getting better, but there is still room for improvement. There are lot of undertreated woman. Classic, massive heart attacks are most typical among later middle age men, but valve issues, atrial fibrillation, strokes, and high blood pressure are just as common in women as in men.
You are involved in developing new guidelines for the American Heart Association. Can you tell us about that?
My mentor, Roger S. Blumenthal, who is the director of the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, is chair of the new guidelines being developed by the American Heart Association. It is a national effort but we are fortunate that Roger is a thought leader in preventive cardiology. The most recent guidelines are from 2013; new blood pressure guidelines will be updated later this year.
One change is that when we prescribe statins, which lower cholesterol, we are doing so based on a patient’s risk of cardiovascular disease.
We look at age, blood pressure, cholesterol, smoking status, diabetes, and hypertension to calculate a patient’s estimated risk over 10 years. Different than in the past because we are not looking at just cholesterol. If the risk is over a certain threshold, we recommend statin drug based on guidelines. This is a change because we are not just looking at cholesterol level.
To measure risk, we use a regression, a statistical technique and mathematical model. If over 7.5 percent, the guidelines recommend a cholesterol lowering statin, even if a patient’s cholesterol is low.
One thing that has become more evident in the last couple of years is the lower the cholesterol, in particular LDL cholesterol, which is the bad cholesterol, the less likely a patient will have a CVD event.
What can people do to lower their cholesterol who don’t take medication?
Dietary guidelines have been a source of confusion. I am not sure that science and nutritional epidemiology is good enough to be fully relied upon. We don’t have a lot of high quality studies in that area.
Recent studies have focused on carbohydrates rather than fat. The fat you eat doesn’t necessarily translate into what fat is in the blood. We still recommend that you avoid saturated fats. There is controversy about other types of fats as related to cholesterol levels. It is less clear that what you eat directly relates to cholesterol levels.
That being said, a diet high in vegetables, fruits, fish oils, fiber and nuts is associated with healthier outcomes.
Weight loss is crucial. A Mediterranean diet, along with exercise and activity, can help.
The problem in the Western world is to find the time to eat healthy when we are in an environment with unhealthy food all around us.
In our culture, we need to allow people more time to be active and time to eat healthy. In America, you can get a lot of bad food for relatively cheap.