Transcript

Dr. Frank Domino:

Sheila is a 51-year-old teacher who comes in today for routine follow-up of her type two diabetes. She has been well controlled on diet, exercise and metformin. Her most recent A1C is 6.1. She doesn't smoke and her blood pressure is well controlled without any medication, today it's 110/70. Her labs prior to today's visit show that her total cholesterol is 190, with an LDL of 122, and an HDL of 44. Many of her friends are taking a statin and she wonders if she should as well.

Hi, this is Frank Domino, Professor in the Department of Family Medicine and Community Health at the University of Massachusetts Medical School. Joining me today to discuss the new cholesterol guidelines is Alan Ehrlich, Associate Professor in the Department of Family Medicine and Community Health at the University of Massachusetts Medical School and Executive Editor at DynaMed. Hi Alan.

Alan Ehrlich:

Hi, Frank.

Dr. Domino:

So, these guidelines are quite detailed and they've done a great deal of expanding the data they look at to help come up with them. Can you talk about what the new guidelines speak to regarding primary and secondary prevention?

Alan Ehrlich:

Sure, so the new guidelines were developed by the American Heart Association, American College of Cardiology, and they brought in actually a lot of other guideline groups to make sure that there was broad representation of various interests. And what they have done is they have kept some things similar to before, and some things have changed. What is kept similar is the risk groups, which include for primary prevention, anyone ages 20-75 who has an LDL greater than 190, any patient who's 40 to... Well, 74 up to 75 who has an LDL over 70, if you're diabetic, and then for people who aren't diabetic or have an LDL less than 190, then it gets down into looking at risk groups. So for people who are not diabetic and their LDL is less than 190, then you're going to wind up calculating their 10-year risk and determining whether they're low risk, which would be less than 5% chance of a cardiovascular event over 10 years. They have a borderline category which is 5%-7.4%, intermediate risk is 7.5%-19.9%, and high risk is anyone 20% risk or greater.

So they have those risk categories and within those risk categories if you're going to treat, first-line therapy is still statins, the difference is there is now treating to target and the target is based on LDL reduction. Typically, you wanna see an LDL reduction of greater than 50%, and you wanna get that LDL less than 100% and for many conditions you want that less than 70%.

Dr. Domino:

So, for even primary prevention they want an LDL reduction of greater than 50% or less than a 100%?

Alan Ehrlich:

It varies based on what your baseline is. So for instance, if your initial LDL reduction would typically be 30% for a routine patient, but if you had... If you were high risk, and your 10-year risk is over 20%, then they do want that LDL reduction to be over 50%.

Dr. Domino:

Okay, great. Well, that's going to expand both the number of people we become a bit more aggressive with, with regard to treatment, in particularly trying to get those LDL levels lower. How do we decide which patients we should be aggressive with, with regards to treatment with medication?

Alan Ehrlich:

So I think it's a mixed message from the guideline group. It isn't that we need to be more aggressive with all patients. But, first of all, if you do have someone for whom you think you want to treat, then yes, go ahead and try and treat to these more aggressive goals, which includes adding the non-statin therapies, particularly as it may be, as the first line second agent. But, one of the things the guidelines did is they emphasized the importance of shared decision making in deciding who should be getting treatment in the first place. And for people who aren't high risk, particularly that intermediate risk group, there's a lot more nuance there in these guidelines and emphasis on talking to patients about what is the benefit, and the absolute benefit is often quite small. It may be statistically significant, but you're absolute risk reduction may just be 1% or 2%. And so they've looked at a lot of other factors that might help influence that decision as to whether or not to in fact start therapy.

Dr. Domino:

It makes intuitive sense that we become aggressive with folks who are very high risk. And for secondary prevention, I think many of us are already in that world. I do wonder how I help someone like Sheila, now she has diabetes, but she's active, her diabetes is under good control, her LDL and total cholesterol seem pretty good. How do we decide with her what our treatment goal should be?

Alan Ehrlich:

So, if you were to calculate her 10-year risk it's relatively low, but because her LDLs over 70 and she has diabetes, the guideline to recommend that she get treated and that's the end of the story for that. For other... If she didn't have diabetes, she would probably not need treatment. So there are particular things that can make a big difference.

One of the things to focus in on in terms of counseling patients, are these, what they call risk-enhancing factors. And these are new in this guideline. Previously they had looked at certain biochemical parameters around things like CRP, or other factors that are not considered primary for making decision but can help influence, and what they've done with the risk-enhancing factors is to add a lot of clinical history factors that might make a difference. So for instance, a woman who has a history of preeclampsia that would increase your tendency to think about she should be treated with statins, it would certainly put her at higher risk. The same thing if someone's got chronic kidney disease, or they've got Peripheral Vascular Disease as evidenced by decreased arterial brachial index. So there are things like that.

Another category is anyone with a chronic inflammatory condition, such as psoriasis or rheumatoid arthritis. These are all people for whom these extra factors might tip you towards encouraging them towards a statin.

One last thing that the new guidelines do that would enter into this shared decision making, is there's more information about different ethnic groups. For instance, people from South Asia tend to have higher risk for cardiovascular events, whereas East Asians may have a lower risk, and much of how we calculate risk based on the pooled cohort equations, are primarily based on a Caucasian population. They do have separate analysis for blacks, but there isn't really the breakdown for other ethnic groups.

Dr. Domino:

Alan, can you just please summarize what our treatment goals are based upon classification?

Alan Ehrlich:

Okay, so the goal is going to be based on whether we're talking about primary or secondary prevention. For primary prevention there's the group of patients who start out with very high LDLs, you wanna get their LDLs less than 100, if you can. So if they're over 190, get it less than 100. If you have diabetes, or if you have elevated risk based on the pooled cohort equations and you're going to be treated, your initial target is gonna be a 30% reduction in LDL. If you're risk is over 20%, that target should be a 50% reduction. If you have already established cardiovascular disease, then the target is a 50% reduction in LDL, and the goal is to get that LDL less than 70%.

Dr. Domino:

So, Alan, you've given us those very clear cut goals, what if patients taking high dose statins cannot reach goal?

Alan Ehrlich:

So the first line drug will be as it to maybe for most patients, the guidelines talk about using the PCSK9 inhibitors and they do recommend adding those if necessary to achieve goal, particularly in patients with either a family history of severe hypercholesterolemia or in patients who need secondary prevention. The one thing they do point out is that they're very expensive and they consider these to be a low value treatment. If the cost were to come down substantially, such as by two-thirds, then this would alter how the committee viewed it but for now they recommend considering it, but acknowledging the value may be low and the absolute risk reduction of using them is not great in many of the populations.

Dr. Domino:

Alan, thank you so much. Practice pointer: For prior prevention of cardiovascular disease, the American Heart Association's new guidelines gives us clear parameters about what our treatment goals should be for lowering patient's cholesterol.