Primary Prevention for CAD/PAD

Experts in the field of CAD/PAD management discuss the ACC and AHA guidelines and lifestyle recommendations for primary prevention of coronary and peripheral artery disease.

James Groce III, PharmD: Paul, could you discuss the primary prevention for coronary heart disease [CAD] and peripheral artery disease [PAD], as recommended by the American College of Cardiology [ACC] and American Heart Association [AHA] guidelines?

Paul Dobesh, PharmD: Sure. Primary prevention is hard. It really is kind of preventing disease from ever happening in the first place, which is what we’d love to do. Really, what it comes down to is identifying those patients, like you said, who are at risk. If we remember that this is atherosclerotic disease, then what are the risk factors for atherosclerosis? Many of us are familiar with these, right? It’s the smoking, it’s diabetes, it’s dyslipidemia and hypertension, those things that we can modify. So we know, right? If somebody smokes and they stop smoking, their risk of mortality goes down. If someone has high blood pressure and we get them to goal blood pressure, they live longer. If you have dyslipidemia, give them a statin. These are all highly proven therapies. Diabetes, right, we want to try to keep their glycated hemoglobin A1C to less than 7.0, and possibly even new therapies now in diabetes are potentially having an impact on cardiovascular events. So really, for primary prevention, it is going after those risk factors for atherosclerosis. Obviously, diet and exercise play a part in that, going against obesity and other things like that, so we try to control those things we can.

There are other things we can’t do, right? We all get older, and regardless of your gender, eventually you are going to have risk based on your age. You can’t beat your genes, right? So, if you have a family history of early-onset disease, you might have a genetic predisposition to early-onset disease. But there are definitely a number of things that we can address from a risk factor standpoint, and hopefully with these patients, when we treat their hypertension, dyslipidemia, smoking cessation, things like that, we really have an impact on them never coming down with coronary artery disease or peripheral artery disease or any atherosclerotic consequence.

James Groce III, PharmD: Paul, what is the role of aspirin in primary prevention?

Paul Dobesh, PharmD: That’s rapidly evolving. If we were having this conversation 3 or 4 years ago, the answer probably would be different. Regarding the data right now, a couple of big studies just published in the last few years, a number of them in the New England Journal of Medicine, showed that aspirin for primary prevention probably doesn’t have as much of a role as we used to think it did. We used to say, “Oh, yeah, once your patients get over 50 or 55, it’s not a bad idea to take a baby aspirin every day,” and some of the newer data are suggesting that because of the work we’re doing with hypertension and lipids and things like that, the addition of low-dose aspirin doesn’t really seem to provide the benefit we had hoped it would. There is obviously risk, even though it’s a little itty-bitty pill that you can chew. There’s risk of bleeding when you give patients anticoagulant agents. So the role of aspirin in primary prevention, especially for coronary disease, just seems to be limited.

In peripheral artery disease, it’s a little bit different. The recommendation is that it’s a lower-level recommendation, but it’s not been taken out of the guidelines. That’s one of the wonderful things about doing something what we call an ankle-brachial index [ABI]. Pretty much any clinician who is listening to this, I bet, can do one. It’s not overly complicated. You need an ultrasound type of machine that does it, but you take the blood pressure in the brachial artery, which is the way you take blood pressures all the time. You get a blood pressure in the posterior tibial artery. It’s a closed system; the pressure should be pretty similar throughout. But if you have a drop in the blood pressure in the leg, that’s actually very high sensitivity and specificity for diagnosing atherosclerosis noninvasively. There are some data that suggest that even for patients who had asymptomatic PAD based on simply an ABI, the aspirin might have some benefit. It’s not as great as if you have the disease, but that still does show up in the recommendations as a possibility.