AHA 2018 — Expert commentary on the 2018 ACC/AHA cholesterol guideline: critical changes for your daily practice

  • Aviva Schwartz
  • Clinical Essentials
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An excerpt from a presentation by Seth Martin, MD, MHS, FACC, FAHA, FASPC.

Dr. Martin is an 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.

What’s most practice-changing about these guidelines?

I would say that numbers are back, specifically with relation to LDL cholesterol, which is now used as a threshold to drive optimization of therapy. In our highest-risk patients with established cardiovascular disease—those patients who’ve had heart attacks and strokes previously—the new guidelines really emphasize the importance of maximizing risk-reducing therapy based on the latest randomized controlled trials.

Of course, we’ll maximize their heart-healthy diet and exercise, and their statin therapy. Nothing is new there; that’s what we have been doing for years and since the prior guidelines. But what is new are the results from trials like IMPROVE-IT with ezetimibe, and the FOURIER and ODYSSEY Outcomes trials, showing us that on top of statin therapy we can get additional risk reduction by lowering the LDL level to optimize cardiovascular risk. In those trials, an inclusion criterion, for example in the PCSK9 trials, was an LDL cholesterol of 70 mg/dL or more. And so, the guidelines have highlighted that as a threshold to consider additional therapy. The first step is to add ezetimibe, follow the patient up with lipids 4-12 weeks later, and if LDL is still 70 or more, to then consider adding a PCSK9 inhibitor.

The guidelines also give a Class IIA recommendation to using newer assessments of LDL cholesterol that we have developed at Johns Hopkins, which avoid the underestimation by the Friedewald equation. So, look for that; talk to your labs if they’re not already doing it to avoid that underestimation by older methods.

New guidance in primary prevention

The new guidelines also give us more guidance in our primary prevention patients. So, in the folks that don’t have prior cardiovascular events, that don’t have diabetes, we’re still advised to use the Pooled Cohort Equations to estimate 10-year cardiovascular risk. But now we have this new categorization where patients less than 5.0% are considered low risk; if 5.0-7.5%, they’re considered borderline. And we have this broad 7.5 to less than 20% group that’s considered intermediate risk, and then anything 20% or more is considered high risk.

The clinician-patient risk discussion is key

That broad intermediate risk may represent half or so of our patients that we’re assessing in primary prevention, and the guidelines really give a lot of opportunity for personalized therapy in this group through the clinician-patient risk discussion or shared decision-making.

This may happen in 1 visit or it may happen over multiple visits in your practice. You can take a team-based approach using other folks on your teams—your nurses and pharmacists that work with you in clinic. Have a conversation with the patient about their risk, and see if it’s clear if statin therapy should be initiated.

Risk-enhancing factors are a new addition

If there’s uncertainty, the guidelines give a number of risk-enhancing factors, such as metabolic syndrome, chronic kidney disease, family history, measures if they are available, such as apo-B or Lp(a), that would push towards statin therapy.

CAC scoring has new prominence

If the risk-based decision is still uncertain despite considering those factors, the guidelines now give a more prominent role to subclinical atherosclerosis imaging, particularly with the coronary artery calcium score. It has a IIA recommendation in the new guidelines.

What’s considered a high score has been lowered from 300 down to 100, or above the 75th percentile. That would strongly favor statin therapy. A score of 1-99 would also favor statin therapy, but maybe it would be more moderate than high-intensity. Now, a score of 0 could be used to delay therapy while focusing on lifestyle. Consider reassessing the patient in about 5 years and seeing where you’re at; you may consider repeating a calcium score at that time.

So, this power of 0 contained in the calcium score, which can be present in about half the patients that you do a calcium score in, is really featured in the new guidelines and represents a big change since the last iteration of the guidelines. So, I’d say, if you’re not familiar with coronary calcium, read a bit more about it in the new guidelines. Start talking to your colleagues and thinking about how you could integrate that into your practice.

These were just some of the features of the guidelines that stood out to me, but really, these guideline additions can better inform discussions with your patients and help you decide on more effective and personalized therapy.