This transcript has been edited for clarity.
Salim S. Virani, MD, PhD, FACC: Hello. I'm Salim Virani from Baylor College of Medicine. I'm joined today by my two colleagues Dr Erin Michos, from Johns Hopkins School of Medicine, and Dr Donna Arnett, from the University of Kentucky College of Public Health. We were all involved in the development of the updated American College of Cardiology (ACC)/American Heart Association (AHA) guideline for primary prevention of cardiovascular disease (CVD). We are discussing that today for our clinicians in internal medicine and family practice.
Dr Arnett, can you explain to us which segment this guideline applies to?
Donna K. Arnett, MSPH, PhD: This guideline is primarily intended for all adults in the United States for primary prevention of CVD. Essentially, this guideline applies to everyone who has not had an overt cardiovascular event.
Virani: Dr Michos, what cardiovascular events are we talking about?
Erin D. Michos, MD, MHS: Not only are we trying to prevent atherosclerotic CVD (ie, coronary heart disease events and strokes), but these guidelines also emphasize the prevention of heart failure and atrial fibrillation for a more global prevention approach.
Virani: Perfect. Let's start out with some lifestyle factors. What are some of the key messages for our clinicians if they want to impart changes related to diet or physical activity for their patients?
Arnett: Eighty percent of CVD is preventable, and it's preventable through these lifestyle measures. Our diet recommendations emphasize a diet that is rich in fruits, vegetables, legumes, nuts, fish, and whole grains as a baseline diet for everyone to follow. Limit the intake of red meat, processed meats, sodium, and cholesterol. Those are the major components of our diet recommendation.
Interestingly, we have for the first time a harm recommendation around trans fats. We should eliminate trans fats from our diet.
Virani: What about physical activity recommendations? Have they changed or stayed the same?
Arnett: Physical activity recommendations are the same, which is 150 minutes of moderate physical activity (eg, a brisk walk) or 75 minutes of vigorous activity (eg, jogging or swimming) per week. One addition is that we want to emphasize that activity is important. We do not want our patients to think they have to exercise or go to a gym or restrict their activities to those kind of things; we want them to be more active. If they cannot meet those recommendations of 150 or 75 minutes per week, they should do something, because every little bit of movement away from the couch is beneficial.
Virani: There is a curvilinear association showing that increasing physical activity by 10-15 minutes daily has a lot of benefits, at least when we look at coronary heart disease events. Should clinicians be aware of anything on sedentary behavior?
Arnett: We do have a recommendation that it may be reasonable to not be sedentary. There are some early indications that standing may be of benefit. We do have a recommendation about that, and I think as the evidence grows, that level of evidence and recommendation will grow stronger.
Managing Major Risk Factors
Virani: Dr Michos, can you summarize some of the recommendations related to management of major risk factors or disease conditions, such as diabetes, hypertension, and cholesterol? What is the first step we should take when we see a patient in the clinic?
Michos: We heard from Dr Arnett that lifestyle is still the foundation of prevention. But when we start thinking about drug therapy, it's important to estimate one's absolute risk. We do this using pooled cohort equations to get a 10-year risk. We calculate this because we want to maximize the anticipated benefit of any drug therapy, but minimize harmful overtreatment.
When it comes to cholesterol, we would calculate that 10-year risk. Note that for individuals with diabetes and a low-density lipoprotein (LDL) cholesterol level > 190 mg/dL, you do not need to do that risk assessment; you would just treat with the statins. Among individuals who are above the 20% 10-year risk, you would treat with a statin. But for individuals who are borderline or intermediate risk, often risk is uncertain, so we want to consider risk-enhancing factors. These are clinically available factors that were outlined in the cholesterol guidelines.
If risk is still uncertain after we consider those factors and we are on the fence about whether or not to start a statin, a coronary calcium score can be a tie-breaker. Individuals with a calcium score of zero might be at sufficiently low risk that statins could be postponed or deferred if that is what the patient wishes. On the other hand, for those with a coronary calcium score > 100, we generally recommend statin therapy.
The 10-year risk estimate also carries through to the blood pressure guidelines. For individuals who have blood pressures > 130/80 mm Hg but are also at elevated risk above the 10% 10-year risk, we generally recommend pharmacologic therapy on top of lifestyle. For individuals who are lower risk (< 10% 10-year risk), we do not consider drug therapy until blood pressures are > 140/90 mm Hg consistently.
We actually do not use that risk calculator to make decisions about aspirin in this guideline. On the basis of trials in the past year, aspirin is deemphasized. Generally, most healthy adults who do not have established CVD do not need aspirin for primary prevention. A few patients might still benefit because they are at high enough cardiovascular risk, and that requires a discussion with their doctors. Also, for aspirin, we have some harm statements in the guideline. One of the pivotal trials last year was the ASPREE trial of aspirin in older adults for primary prevention. Not only did it not show benefit, but it showed harm of bleeding and increased risk for death. Because of that, we have a class III recommendation that says: Don't use aspirin in adults over the age of 70 years. We also said: Don't use aspirin in adults of any age who are at increased risk for bleeding.
For diabetes, we again emphasize lifestyle and statins. If lifestyle is not enough, and we're talking about glucose-lowering drugs, metformin is the first line, and then some of those newer classes of medications can be considered, such as a sodium-glucose cotransporter 2 inhibitor or a glucagon-like peptide-1 receptor agonist. These have been mostly used for secondary prevention, but emerging evidence has shown some support for primary prevention. We gave it a IIb recommendation in that it may be considered for primary prevention, and this recommendation may get stronger in the future as we get more data on this new class of medications.
Virani: That was a very good summary. And once treatment starts, the target for blood pressure remains < 130 mm Hg systolic and < 80 mm Hg diastolic. I would remind our viewers that there are some other video discussions available for both the hypertension guidelines as well as the cholesterol guidelines, so if you want to get more details, you can refer to those.
Social Determinants of Health
Virani: The other aspect of this guideline that is extremely important, which a lot of effort has gone into, is the concept of social determinants of health and making it a team sport. What can clinicians take as some of the messages out of those sections of the guideline?
Arnett: We have three specific overarching recommendations that really transcend all of our recommendations that you heard about with diet all the way up through aspirin use. The first is that a team-based approach to primary prevention of CVD is really essential. There is a lot of pressure on the physician to do everything, and having a team that can help us with recommendations for diet or physical activity could be helpful.
The second is that the patient should be at the center of all of these discussions and be working with a physician to make sure that they are making decisions together. That improves adherence and, I think, the outcome for the patient.
Finally, there are social determinants. We have known for a long time how to prevent CVD, and we're not doing a great job in our population. The real reason is because we are not meeting patients where they are. We tell them to eat a healthy diet, but do we know whether or not they can afford fresh fruits and vegetables, or even have access to fresh fruits and vegetables if they live in the inner city? We recommend that they get physically active, but do they have a safe neighborhood they can be active in? For every one of these domains, we want to be asking the patient before making recommendations about these issues.
Virani: It looks like it's very comprehensive and a lot of topics have been covered, but we have to look at the context a little bit more as well when we're giving these recommendations and discussing them with our patients.
Virani: What would be the two or three key takeaways that clinicians should remember from this guideline?
Arnett: I'll start where I just ended. Addressing the social determinants of health in our patients will allow us to create and tailor interventions for primary prevention specific to those patients.
Michos: I agree. It's just as important to realize that social inequalities are a key determinant of cardiovascular risk, so we have to address that.
I want to emphasize again the shared decision-making approach. We have the scientific evidence from the trials that form the basis of the guidelines, and we have our clinical judgment about the patient that is sitting in front of us. Then we have to take in patient preferences and values and meet the patient where they are at. It's the intersection of these three spheres that really has these guidelines emphasize a patient-centered approach to comprehensive primary prevention.
Virani: This has been a great discussion. I thank you both for your time. And to our viewers, thank you.
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Cite this: CVD Primary Prevention Guideline Puts Patients Center Stage - Medscape - Apr 11, 2019.