January 15, 2019
Amit Khera, MD, director of Preventive Cardiology and a Professor of Medicine at UT-Southwestern Medical Center in Dallas, explains how patient outcomes impact primary and secondary prevention and related treatment costs. Stay tuned for part 2 coming soon!
Thank you. This is Dr. Amit Khera. I am Director of Preventive Cardiology and a Professor of Medicine at UT-Southwestern Medical Center in Dallas. I'm also President of the American Society of Preventive Cardiology.
The conversation today is about lipid management, lipid screening, and about preventing heart attacks and strokes. The context here is new guidelines came out in November of 2018 from the American Heart Association, College of Cardiology on cholesterol management.
We'll pause for a second and talk a little bit about the relevance of cholesterol and the opportunity in cholesterol management for preventing heart attacks and strokes.
The neat thing about cardiovascular disease -- and specifically heart attacks and strokes -- is that so much of it's preventable. Now to put a number on that some data suggests that about 80-percent of it's preventable with controlling risk factors and lifestyle.
We really have such an opportunity. I think one of the problems is how to screen people appropriately and to get people on the right treatments and doing the right lifestyle things to take advantage of the opportunity of cutting down that 80-percent risk.
In terms of prevention, a couple of concepts that we're learning over time -- it almost sounds obvious today -- but the earlier you start, the better.
A lot of genetic models have shown that even doing a little bit -- for example, if your cholesterol's a little bit lower from birth -- you get a much greater return on that, meaning maybe an 85-percent reduction in heart attacks and strokes over your lifetime.
A little big from birth is far better than waiting till you're 60 or 70 and then trying to put the genie back in the bottle, as they say. Your ability to reduce people's risk is less than doing a little bit early in life. One big opportunity there is detecting people early that have risk factors like high cholesterol and addressing it early in life and really trying to change their life course.
There's two parts to prevention. We talk about primary prevention and secondary prevention. Primary prevention is avoiding the development of heart attacks and strokes in people who do not have them. That's the majority of the population obviously. Secondary prevention is reducing the chance of having a recurrent heart attack or stroke in those that have had them.
In terms of the United States, about 16 million people or so have coronary artery disease and roughly 5 or 6 million have had a stroke, so that's a sizable amount of people that are in secondary prevention. I'm going to start talking about secondary prevention first. I'm not saying either one is more important but they're just a bit different.
The reason secondary prevention is different is because the first part is we've already easily identified someone who's at high risk for another heart attack and stroke.
For example, if someone has had a heart attack in the past, their chance in the next 10 years of having another heart attack or dying of such is somewhere between 20- to 50-percent depending on additional risk factors. These people are not hard to find. There's no secret here. The part though is being aggressive about lowering that chance of having a recurrent event.
In cardiology, in secondary prevention, we have tons of data and literature. We know exactly what we're supposed to do. The issue is actually implementation of that. Every patient gets on aspirin, exercises, sees their doctors, takes their medicines, but as it comes to cholesterol, cholesterol management has a critical role.
We do know that every patient in the old guidelines and the new guidelines that just came out, every patient with atherosclerotic cardiovascular disease -- heart attack and stroke -- is supposed to be on a high-intensity statin.
A strong dose of a statin -- what we call Lipitor 80 milligrams, or Crestor about 20 or 40 milligrams -- that's what a high-intensity statin is. It's really not much to think about. There's good data to suggest that people on the high-intensity statin do better than on lower doses in terms of reducing heart attacks and strokes.
It makes a big difference. On a high-intensity statin, we can lower the recurrent risk by about 30- to 50-percent, so that's meaningful. You have a high-risk patient. If you can cut the risk down by 30- to 50-percent that's meaningful.
It's meaningful because it's obviously morbid for them to have another heart attack and stroke. But from a cost prevention perspective, we can avoid a very costly recurrent heart attack or stroke which is a big deal.
Secondary prevention is quite easy if someone's high-risk, you know it because they've had a heart attack and stroke. They need to be on a high-intensity statin, regardless actually of their cholesterol levels because statins lower risk. Wherever you're starting cholesterol is you'll cut your risk by 30- to 50-percent.
What's new though since the last guidelines in 2013, we've had a couple of new drugs that have come out with more evidence -- one is called Zetia, or ezetimibe. On top of statins, Zetia can lower LDL, your bad cholesterol by about 20-percent further.
Zetia can be helpful in lowering cholesterol. It's not quite as expensive as another drug I'm about to tell you about. It now is generic, so it's not necessarily cheap, but it's not terribly expensive.
Again, it's not very strong, so it doesn't lower cholesterol that much. There has been a study that when you add Zetia to a statin drug in patients who've had heart attacks, you can further lower the risk of heart attacks and strokes but very modestly.
The new guidelines said if you're on a high-intensity statin, which everyone should be on, if your bad cholesterol LDL is above 70 -- so it's not quite as good as we'd like it to be -- it's reasonable to add Zetia, so that's a new change in the guidelines.
The second part to that though is another class of drugs called PCSK9 inhibitors. These are new drugs that were FDA-approved in 2015.
It's an injection that you give yourself every other week, and it drops your cholesterol by 50-percent. They're very strong and potent and they can markedly lower LDL.
Since the last set of guidelines, there have been two big studies showing that when you add these shots on top of a statin in patients who have heart disease, you can further lower the risk of a heart attack and stroke.
The issue though is those drugs are pretty expensive. They were $14,000 a year. There's two manufacturers. One company dropped the price to $5,800 a year, but that's still quite expensive.
When you get the cost effective analysis -- and that was in the guidelines by our QALY, quality-adjusted life-years -- at $14,000 a year, they're not cost effective, being more than $150,000 for every quality-adjusted life-year. Even at $5,800, they still don't quite make what we would consider good cost effectiveness.
That's the challenge. They work, they're beneficial, but they're pretty expensive. The guidelines say that if your LDL is above 70, or you're on a high-intensity statin and going on that Zetia, ezetimibe drug, it's reasonable to use these PCSK9 inhibitors.
They're not for everybody. It's a trade-off between us trying to be aggressive with cholesterol-lowering but appreciating the cost incurred in achieving that. That's secondary prevention. I'm going to pivot a little and talk about primary prevention.
Primary prevention again is looking at avoiding the first heart attack in someone's lifetime. Now there are many things that we think about, not just cholesterol management.
If you really wanted to be effective in prevention, it's not just cholesterol, but it's smoking, diabetes, high blood pressure, exercise, nutrition, all those things. For this discussion, I'll talk about cholesterol.
In primary prevention, the old guidelines in 2013 said if your risk of having a heart attack or stroke in the next 10 years is above 7.5-percent then you should consider being on a statin. Interestingly, or maybe confusingly, that didn't necessarily depend on your cholesterol level which sounds a little unusual.
The reason that is, is because we know statins lower risk. If your risk is higher -- above 7.5-percent -- if you're on a moderate-intensity statin, you'll lower your risk by a third. The guidelines said that was the number needed to treat about 39 people over 10 years to reduce one cardiovascular event.
That was deemed to be in some analysis cost effective. I want to be careful because cost effective -- meaning cost less than 50,000 or less a year for one quality-adjusted life-year -- that's different than cost savings where it actually on net reduces cost, but it seems to be cost effective.
The one issue is that by using this risk calculator -- and saying if you're above that percent you should be on a statin -- it turns out that in 2013 when that information came out and those recommendations, it increased the amount of people in the United States that should be on a statin from 46 million to 58 million. It increased by 12 million the number of people in the United States for statins recommended.
What the new guidelines did in 2018 is say, well, can we be more precise about people's risks? That 7.5-percent came from an accrued calculator that we used using age and blood pressure and cholesterol and things like that.
A new test has come out called coronary calcium scanning -- maybe not that new, but has been more frequently used -- which is a CAT scan of the heart.
It's a quick and simple one, costs about $99 or less. Essentially, if you have calcium in the arteries, you have atherosclerosis or build-up.
They said the following -- what if you're on the fence? Your risk calculator says your risk is a little higher, but we're not sure if it really is, and you're not sure you want to take the medicine, so realizing patient preference a little bit more.
It turns out that when patients have a score of zero, if they have no calcium then maybe the risk isn't that high and they can defer and not take a statin.
There was a paper done which showed out of all patients where statins were recommended, half of them had a score of zero, maybe didn't need to be on one. This is in primary prevention, by the way.
The take-home points are the guidelines said, well, if you're on the fence -- if your risk is between 7.5- to 20-percent, and you're not sure if you want to take a statin or not -- after having a good discussion with your physician, you can consider doing this scan to more precisely determine if you need one or not. If you score 0, probably not, if it's above 100, probably should.
That may be helpful to target the treatment of statins more effectively to the people who need them more, avoiding it in those who it would be less beneficial, but providing it to those who are higher risk where it would be more cost effective.
The primary prevention, the new parts of the guidelines are more shared decision-making and more tools to help in that shared decision-making for statins. That is the summary in general of the new guidelines and some of the highlights and topics that were found in them.