Q&A with Dr. Hazen about Coronary Artery Disease Prevention

Podcast Transcript

Announcer: Welcome to Love Your Heart, brought to you by  Cleveland Clinic's Sydell and Arnold Miller Family Heart and Vascular Institute, These podcasts will help you learn more about your heart, thoracic and vascular systems, ways to stay healthy and information about diseases and treatment options. Enjoy.

Dr. Stan Hazen: Hi, my name is Dr. Stan Hazen. We just finished a web chat describing and answering questions about preventive cardiology, and we had many interesting questions and I thought I'd go over some of those answers for those of you who are listening to this. So one of the questions that was asked is when should someone go to a preventive cardiology clinic? And the truth is is that's can happen in any middle aged individual, for example, to get an idea about what their global cardiac risk is. But the answer also could be different for someone who has a strong family history of heart disease or known risk factors for heart disease.

We often will see patients at a much earlier age or younger age when they have a strong history of heart attack, stroke or even sudden death in the family. And it's very common for unfortunately for someone to have a serious illness or death in the family that's cardiac in nature, and then multiple family members, brothers, sisters, and even sometimes the kids who might be college age will come on in and be evaluated to see whether or not they are at increased risk than might otherwise be expected, for example, by traditional risk factors.

What do we do in a preventive clinic? We actually try to globally assess a person's risk. That means looking at multiple things, but we focus on the lipid levels such as cholesterol and triglycerides. We focus on nutrition efforts and diet, which plays an important role in a person's cardiovascular health. We also focus on exercise programs, because we see that these and others have seen that these can play a significant role in a person's overall cardiovascular health. But we actually look at many things, blood pressure control, smoking cessation, we call it cardiovascular behavioral health for people who have issues with anxiety or depression or just recently were diagnosed with heart disease and are depressed, we will actually help them see, whether it be a psychologist or psychiatrist, and so we do a whole array of programs including weight reduction programs and others to try to globally reduce their cardiac risk.

And what we will also focus on is trying to individualize or tailor the program for each subject. So in one individual it may include concerns about sleep and needing to get a sleep study and working worries about sleep apnea. Another person, it might actually be focused more on blood pressure control, but in everyone we try to touch on each of the major risk factors and potential contributors to cardiac risk and to get the help that's needed, if it is needed in terms of other healthcare providers to more globally help to prevent either the development of heart disease or the progression of existing heart disease. About a third to a half of the patients who we see in our program have no known heart disease, and the majority though have existing or documented heart disease.

Another question that was asked had to do with what kind of tests do we order in preventive cardiology clinic? And we do the routine ones such as a fasting lipid profile, or a basic metabolic panel that looks at kidney function and electrolytes and fasting glucose and looks for issues related to diabetes. But we also will look at more specialized tests to help identify people who are at heightened risk for developing cardiac disease or progression of their cardiac disease, such as various markers of inflammation. One of the tests that we will also look at, especially at least once, is something called a Lipoprotein a or LPa. This is a test that is actually linked to premature development of heart disease. It often runs in families, so people who have a strong family history of heart disease, we're always thinking about looking for an elevated LPa when we see that.

We focus on globally more aggressive risk reduction efforts and we actually move the goal posts to more aggressive goals than what might otherwise be recommended by typical national guidelines. We also, when we see that level is elevated, we'll focus on not only risk reduction in the patient we're seeing, but we also make some recommendations about screening for heart disease risks in first degree family members, so siblings and even children, to help identify those that are at heightened risk for the development of cardiac disease who might otherwise not have been recognized by traditional risk factors.

Another test that was asked about is the calcium score. When do we use it? How do we interpret it? First, what is a calcium score? It is a radiologic or radiographic test that actually measures calcification in the degree of that in the coronary vascular bed. A high level of calcium score does indicate a heightened risk for cardiac disease. What we have to realize though is that an elevated calcium or a low calcium score does not exclude the possibility of having cardiac disease. That's because calcification of the vessels is a very late stage of the atherosclerotic process, and it can actually be seen as more of a healing over or a scarring of the atherosclerotic plaque. The calcified plaque is a more stable form of atherosclerosis than the noncalcified lipid rich and inflamed plaque. And so if someone has an elevated calcium score, that is a score over 100, that suggests increased risk and we move to more aggressive preventive efforts.

We do not get serial calcium scores once you have a positive calcium score. You can think of a calcium score as being like a pregnancy test. Once it's positive, testing it and getting more information to see is it even more positive is not helpful. It has no prognostic value, the interval change in calcium score once it's positive. And so we don't use the calcium score routinely in everyone, but we do sometimes as an adjunct to helping to identify who is at increased risk amongst primary prevention patients, especially where we haven't other reason to think that they're at increased risk, and other tests are normal and if the subject is still really concerned, we sometimes can go ahead and get a calcium score to see is there any other reason to think a person's at risk we might otherwise not be recognizing.

One of the tests that we sometimes will perform is something called TMAO stands for Trimethylamine N-oxide. This is a metabolite that's made by gut microbes. It actually is a very strong predictor of the development of heart disease and for thrombotic events like heart attack and stroke. It also tracks with mortality risk quite well. Elevated levels of TMAO are linked to, not only cardiac risk, but they also tend to go up depending upon what a person eats. And that's because this compound is made by the metabolism of nutrients that are abundant in animal products, and in particular red meat. A very recent study that just came out from our group showed that individuals who eat a diet that is rich in red meat for their protein source can have a TMAO level that's on average three fold higher than if they were to switch their diet to the protein source coming from white meat or non-meat sources of proteins such as vegetables.

And so if a person has a high TMAO, what do we do? We recommend more global preventive risk reducing efforts. We lower things like LDL goal. Because it's associated with platelets, stickiness and clotting risk, we look to see whether or not addition of low dose aspirin to their regimen will be helpful, and make sure that there are no clear contraindications though before starting a low dose aspirin. And the other thing is as we look to their diet and see whether or not some changes in the diet might be beneficial in helping to reduce TMAO levels. And just like one can follow a cholesterol level or a triglyceride level or a glucose level with dietary changes and help to tailor a person's diet, you can also follow TMAO levels with diet changes. And recent studies have shown that when one switches from a predominantly red meat diet to, as I mentioned, a white meat or non-meat protein source diet, within a month, the TMAO levels will come down on average three fold in most subjects. And so a, it is a addressable or intervenable a risk factor.

Another question that was asked was, are there any other tests that we perform? What tests do we routinely do and do we do stress tests in patients who are seen in preventive cardiology? And the answer is it really depends on the patient's history, their risks and their symptoms. We don't routinely, for example, get stress tests in every single patient, but if the symptoms suggest that there may be a concern or an issue, then we go ahead and get an exercise stress test. Oftentimes what we will do for a high risk patient is also do an exercise stress test as part of our development of the exercise program to actually evaluate what is a safe amount for them and whether or not it is safe for a higher risk patient to be doing the type of exercise program that we want.

And lastly, you may be asking, and one of the questions that was asked is how much exercise? And on average what we recommend is that someone do three to five days of sustained cardio based type of exercise per week. And that each session should be anywhere from 30 to 45 minutes, and it can be just simply walking at a brisk pace, but it can be anything that's comparable to that level of activity. So whether one wants to hike or bike or swim or Pilates or Jazzercise, there are questions about yoga. I will say that you want to have the amount of effort that is comparable to a brisk walk. So walking on a treadmill, that would be walking at a three to three and a half mile per hour pace continuously without stops for a 30 to 45 minute period. And whatever the choice of exercises that is comparable to that is really all that is needed.

As patients tend to get up in age, we also sometimes then start suggesting addition of weightlifting or things to help tone and maintain muscle mass and fitness. But that is not really a cardio benefit. That's really maintaining vitality and just strength issues. And from a cardio standpoint, it's getting the heart rate up and doing a continuous level of exercise. That tended to be the topics that we covered during the web chat. And if you have any questions or concerns, we're welcome to seeing you in the preventive cardiology program here at the Cleveland Clinic.

Announcer: Thank you for listening. We hope you enjoyed the podcast. We welcome your comments and feedback. Please contact us at heart@ccf.org. Like what you heard? Please subscribe and share the link on iTunes.