Secondary Prevention for CAD/PAD
Tags: CAD,PAD,Cardiovascular Disease
Two experts review the current recommended treatment algorithm for CAD/PAD.
James Groce III, PharmD: If you could, please, discuss the secondary prevention for CAD [coronary artery disease] and PAD [peripheral artery disease]. What’s the current recommended treatment algorithm in managing a patient who has coronary artery disease and/or peripheral artery disease? That is to say, what are the current guidelines by the ACC [American College of Cardiology] and AHA [American Heart Association]?
Paul Dobesh, PharmD: Sure. In a patient who has had a coronary event, if a patient has an acute coronary syndrome, it’s a little different. After an acute coronary syndrome, dual antiplatelet therapy is a grade 1A recommendation. It’s the highest thing we should do. It’s nonnegotiable; we should be doing that for a year. That’s really what the guidelines say: for the first year, dual antiplatelet therapy. It doesn’t matter what type of stent you get. It doesn’t matter if you get a stent or not; even if you’re medically managed, bypass surgery, dual antiplatelet therapy after an ACS [acute coronary syndrome] event is clearly indicated for that first year.
After that, most of the things we do are, once again, going after the same risk factors that gave us the disease: treating them with a high-intensity statin; getting their blood pressure under control; if they smoke, getting them to stop smoking. For other things like giving ACE [angiotensin-converting enzyme] inhibitor therapy or ACE inhibition therapy, it doesn’t probably matter of it’s an ACE inhibitor or an angiotensin receptor blocker [ARB]. Several studies have shown that they have what we call a vasculo-protective effect—so, adding those to the regimen.
Of course, then there are agents that try to reduce recurrent chest pain episodes, and that’s where it kind of spills over into the patient who has stable ischemic heart disease. Stable ischemic heart disease patients don’t need necessarily dual antiplatelet therapy, but they definitely should be on aspirin. They definitely should be on the ACE or ARB. They definitely should be on a high-intensity statin. Smoking cessation and blood pressure control are probably going to help get some of that with your ACE or ARB. It’s about controlling the episodes of the chest pain, which is usually using something that lowers the heart rate, like a beta-blocker or a verapamil-diltiazem type of calcium channel blocker, to continue to try to control chronic episodes of chest pain. Other agents then could be added, such as long-acting nitrates, dihydropyridine calcium channel blockers, or even ranolazine. So from a medical perspective, that’s kind of where we are in the management of coronary artery disease.
Chronic PAD has been, unfortunately, very woefully, poorly studied. Aspirin right now is the only thing we’ve ever had that’s been shown to reduce cardiovascular events. Again, remember that if you get atherosclerosis in your peripheral arteries, especially enough to give you symptomatic disease, you probably have it in your coronaries, even though you may not have symptoms, and you probably have it in your cerebral vessels. It’s a systemic disease. Really, all we really have right now is aspirin in those patients.
As far as trying to control symptoms, the literature has shown that there are many studies. Really, the drug that’s had the best effect that I’ve seen as I reviewed this literature and had a chance to publish on it is cilostazol. Cilostazol doesn’t change the cardiovascular events, though; cilostazol basically helps improve walking distance. It’s mixed. Many people will swear that it’s the best thing that they’ve ever had to help improve their walking distance, and I’ve had other clinicians tell me they think it’s like a placebo. But it does seem to have the best data. But after that, many of us who grew up in the days of pentoxifylline—it doesn’t work. Other things have been used—carnitine, propionyl-L-carnitine, just all kinds of different things have been attempted, but really nothing to improve the symptoms. So really, it’s like aspirin and cilostazol are about it for peripheral artery disease patients. There’s really not much there.
Patients may get procedures, just like in their peripherals, just like they may in their coronaries, but as for what we do after those procedures, there’s not really a, quote, unquote, guideline to follow. You’ll see that some people will get dual antiplatelet therapy; some people will be put on anticoagulants. Realize, I had the opportunity to present some of the data on this at the PICAT meeting just a few years ago, and the largest study you’re going to find in this area is less than 100 patients. There’s just not good evidence about what to do in this setting, and really, I think the PAD patients have really been neglected when it comes to trying to find a way to better their outcomes.
James Groce III, PharmD: We know patient care is tremendously complex. If there were a means of prioritizing or creating a hierarchy or a rank order within your institution or for your own clinical practice, what would that look like for you, Paul, as a practitioner and someone who is so involved in this patient population?
Paul Dobesh, PharmD: Especially when it comes to secondary prevention, I think we’re making sure that they have adequate antithrombotic therapy as it exists today. I think that’s one of the first things we try to do. After that, with coronary disease, we focus a lot on beta-blocker therapy, statins, and ACEs and ARBs. For the peripheral artery disease patient, unfortunately, it’s aspirin, and maybe we can get you into an exercise program or something like that. It may work, but many times these programs are not paid for. Unfortunately, for the peripheral artery disease patients, there’s not much of a hierarchy we really have besides making sure that they get their aspirin therapy.