The 2018 ACC/AHA cholesterol guidelines: New guidance in prevention

  • Aviva Schwartz
  • Clinical Essentials
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Dr. Seth Martin, Associate Professor of Medicine and the Director of the Advanced Lipid Disorders Program of the Ciccarone Center for the Prevention of Cardiovascular Disease at Johns Hopkins, discusses two key elements of the new guideline: the role of calcium scoring and the importance of shared decision-making.

What, in your opinion, is the most practice-changing element of the guidelines? 

Dr. Martin: There are a couple of key things. In primary prevention, there’s been expanded guidance with respect to shared decision-making. There’s also a stronger recommendation for coronary artery calcium scores. 

In the prior guidelines, coronary calcium (CAC) had been given a IIB recommendation and if a patient had a score of ≥300 (or ≥75th percentile), that could favor statin therapy. Now the guidelines have brought that number down to 100 to favor using statin therapy. A CAC score of zero has also been given prominence. “The power of zero,” as we call it, really confers a low risk of cardiovascular disease over 10 years and can aid in the decision to withhold pharmacotherapy and focus on lifestyle. Patients with a CAC of zero should be followed over 5-10 years and then reassessed.

The “power of zero” has gained traction based on studies like MESA; some of the work there has helped us understand the power of coronary calcium as an integrator of risk. 

But CAC is not a blanket screening test and should not be used as such, correct?

Dr. Martin: That’s a key point, that it’s not a blanket screening test. It’s a decision aid; it helps resolve uncertainty surrounding decision-making.

What kind of clinical scenario would call for CAC scoring? In other words, which patients warrant this test?

Dr. Martin: If you have a middle-aged patient without diabetes who has an estimated 10-year risk between 7-20% [based on the Pooled Cohort Equation], you can look at certain risk-enhancing factors like family history, how high their LDL is, what their lipoprotein(a) is, whether they have kidney disease or metabolic syndrome, etc. If you’re still uncertain about how to proceed, coronary calcium can be the best “tie-breaker” to help determine next steps.

The average cost of a CAC scan is typically $100 out-of-pocket. Do you think insurance companies will start covering this test?

Dr. Martin: Certainly, these guidelines would support more insurance coverage. And if it does need to be an out-of-pocket expense, the typical price is somewhere in the $70 to $200 range. In Maryland, where I live, the typical price is below $100.

Should primary care providers be ordering CAC tests or is specialist referral warranted? 

Dr. Martin: It depends on the level of comfort that the provider has. I hope that CAC scoring will become more commonly used over time in the primary care community. Coronary calcium is a fairly straightforward, simple test that gives you one number back and, as the guidelines have highlighted, it can lead you to treat or not to treat. This is something that I do envision will grow outside of the specialty community and more into primary care over time. 

And when a patient has a number that’s above the zero threshold , i.e., borderline risk, is that a definite indication to start statin therapy?

Dr. Martin: Yes. When the CAC score is 1 to 99—so it’s positive, but not >100—that would favor statin therapy, as long as the clinician-patient risk discussion is in line with that treatment decision. If the patient has a strong preference to avoid medical/pharmacotherapy, then we still might defer a statin. So, there’s some room for budging within this group, although with a CAC of 1 to 99, we know there’s plaque buildup; those folks would have a net benefit from statin therapy. In the 100+ category, patients have a risk that’s really at the secondary prevention level, which much more strongly favors a statin. 

The clinician-patient risk discussion is strongly emphasized in the new guidelines, which we saw in the last iteration of the guidelines, too. This guideline provides substantive recommendations about what to include in that discussion. Do you think our current medical milieu supports this discussion? How should the discussion unfold when you have 15 minutes to see a patient? 

Dr. Martin: The clinician-patient risk discussion is a beautiful thing in the sense that it opens up the opportunity for personalizing care and really, I think, empowers patients to make the decision that’s best for them—but it may take time. It all depends. Some clinicians and patients may quickly arrive at a treatment decision. The patient may have a strong family history and come in knowing that they want to do everything they can to prevent the same thing that happened to their mom, dad, or other family member from happening to them. Other patients may not arrive at a decision as quickly, and this might be the type of thing that won’t happen in one sitting. You may start the conversation, the patient might go home and read more, think more about the options, and come back to continue the conversation. And that’s perfectly fine. In fact, that’s a good thing because a thoughtful, shared decision is being made.

The clinician-patient discussion doesn’t have to be overly prescriptive or one size fits all. I think, given the flexibility of it, and the reality that we’re making a long-term decision where the benefits really occur over time, it’s not a big deal if you decide today, tomorrow, next week, or a month from now. The bigger deal is that the patient makes the right decision for them and sticks with it over the long term. 

We as cardiologists may engage in discussion with the patient, as well as our primary care colleagues, and there’s an opportunity to further leverage the entire care team—the nurses, the pharmacists, the dieticians that work with us—and have them add perspectives and information that’ll help guide the patient to make the best decision for them.

So, it’s really a multidisciplinary approach.

Dr. Martin: Yes, I think that’s the ideal model. This should be a discussion between the patient and their care team, not just a one-on-one thing with their clinician.

So, to wrap up, what do you think are the major takeaways from this guideline, particularly for primary care providers?

Dr. Martin: I would say the big takeaways are to really dedicate that time to focus on cardiovascular risk with your patients. At every visit, even if it’s very briefly, reinforce the importance of a heart-healthy lifestyle. Discuss intensification of LDL-lowering therapy with your secondary prevention patients. Have the discussions with your primary prevention patients about their risk and next steps. Get familiar with CAC if you can. 

When it comes to therapy, take a closer look at whether a patient who’s at high risk and has an LDL cholesterol of 70 or more should be adding on a nonstatin. 

Work closely with your care team to implement these guidelines with patients. These are robust guidelines that give folks a lot of options. It’s going to take a multi-disciplinary care team approach to get these implemented successfully.

Finally, I would say that these guidelines provide a lot of flexibility to personalize care—take advantage of that and really partner with your patients to figure out what is best for them.