Aspirin's Role in Cardiovascular Prevention With Guy Mintz, MD

Guy Mintz, MD

The news surrounding the US Preventive Services Task Force related to their draft recommendation for aspirin use in prevention of cardiovascular disease was a surprise to many in cardiology, but not because it was unexpected. In fact, many were taken aback by how long it had taken for the Task Force to address aspirin use in the wake of data refuting its benefit dating back to the early 2000s.

Released on October 12, the draft evidence review details more than a dozen randomized clinical trials used in support of their new recommendations, which considers use of low-dose aspirin for primary prevention inappropriate for most patients but underlines the benefit of the approach for secondary prevention. While cardiologists and other clinicians have been aware of the lack of net benefit associated with aspirin use for years, the reality is that many patients are ignorant to the stance change surrounding aspirin, which has been a staple in medicine cabinets for decades. Now, the priority transitions to educating patients about those still stand to benefit from use of aspirin, including those with a history of myocardial infarction, stent implantation or bypass surgery, stroke, or peripheral artery disease.

For more perspective from a practicing cardiologist, Practical Cardiology reached out to editorial advisory board chief Guy Mintz, MD, director of Cardiovascular Health and Lipidology at the Sandra Atlas Bass Heart Hospital at North Shore University Hospital and co-director of the Lipid Center, to learn how he believes the news will impact patients and clinicians.

Guy Mintz, MD, on Aspirin Guidelines for Primary and Secondary Prevention

Practical Cardiology: Where does aspirin fit into treatment algorithms of your patients?

Guy Mintz, MD: I think that's a great question. It's important for us as clinicians to sort out who really benefits from aspirin therapy. So, the first group is secondary prevention: those patients that have had coronary artery disease, whether it's a stent, an angioplasty, a heart attack, or coronary artery bypass surgery or stroke—that's secondary prevention, those people clearly benefit from aspirin therapy.

The issue, with regard to the new guidelines, circles around primary prevention patients, patients that may be at high risk for heart disease, but don't have heart disease. The question is: is there a role for aspirin therapy? Now, aspirin does work. It's a blood thinner and works by interfering with the platelets, but in various groups, you have increased risk for bleeding.

So, the benefit from aspirin is outweighed by the risk of bleeding and the costs associated with gastrointestinal hemorrhage, and so on, so forth. So, the guidelines came out and said, if you have cardiac risk factors and you're below the age of 60, you should talk to your physician about what role aspirin could play. If you're above the age 60 or above and have not been on aspirin therapy, you shouldn't be on aspirin therapy because the risk of bleeding can increase.

When we look back in time, we've been using aspirin, you know, forever. In terms of cardiac prevention, the famous saying goes "An aspirin a day keeps the doctor away". Well back down in 1988, when they had the Physicians Health Study, which actually was an aspirin every other day, it reduced heart attacks in healthy physicians. That's all we had back then. Now, fast-forward to where we are now, and we have very potent medications to lower cholesterol. Statins are main group we use for lowering cholesterol because they not only lower cholesterol, but they also stabilize plaque, they have anti-inflammatory benefits. Beyond the cholesterol-lowering effects, we have lower guidelines for controlling blood pressure and more effective medications for blood pressure control. We have medications for diabetes that low blood sugar, but they also lower cardiovascular events. So, medicine has advanced, and we have many different tools in our toolbox. When you put all these tools in the toolbox, and you lower a patient's risk, the need for aspirin therapy becomes smaller and smaller in that group. So, I think that's where the guidelines are coming from here.

PC: How prevalent do you think current aspirin use is among older patients?

GM: I think it's very prevalent and many patients are taking aspirin without a doctor's knowledge, they just decided "that's kind of the way I was brought up, but that's what I heard". And some doctors may not even have that on their list of medications for the individual patient. So, I think this guideline coming out has certainly proved to be important to move patients back to having discussions with their physicians, because I can tell you since the news broke, we've had 50, 60, 70 patients who have called within the last two days asking, "Should I be on the aspirin? Should I not be on aspirin, but I've been on aspirin for 25 years?" And I like to say we don't do phone medicine, because it's truly an individual assessment based on the patient's risk.

If you have a diabetic patient with peripheral arterial disease, that may be someone that should be on aspirin therapy. So, it's not like as quick as just saying yes or no, on the telephone, we need to really assess the risk. So, there are many patients on aspirin therapy, in practices that we don't even know they're on aspirin therapy. I think this really serves as a wakeup call to educate the patients and educate some physicians as well, should a patient be on aspirin or should they really have all their other risk factors negated, should they be on lipid lowering therapy or enhanced lipid lowering therapy, should they be on better antihypertensive therapy? So, I think that's really where the wakeup call comes in, where the patient could come in and get their cardiovascular risk re-evaluated.

PC: Do you foresee a world where aspirin no longer has a role in secondary prevention or is aspirin always going to be in the back of the medicine cabinet?

GM: That's a great question. So, when you look at what contributes to plaque or cholesterol instability within the arteries, part of that process is inflammation. Aspirin has an anti-inflammatory benefit that was actually shown in the subsequent analysis of the Physicians Health Study data. In the 1990s, they developed a high sensitivity C-reactive protein and they showed that those physicians that were "healthy” but had a higher high sensitivity C-reactive protein were more likely to go on and have a myocardial infarction. So, in terms of secondary prevention, aspirin plays a role from an anti-inflammatory benefit. When the plaque starts to rupture and platelets want to start attaching to each other, aspirin can interfere with that process. If you look at some of the newer data with rivaroxaban, they have an anticoagulant and with a dose of 2.5 milligrams twice a day and low dose aspirin at 81 milligrams per day, they had a 24% reduction in clinical events.

So, as we get more sophisticated understanding what upsets the milieu of the plaque, there's a role for antiplatelet therapy, there's a role for anti-thrombotic therapy, there's a role, as we develop newer agents, for anti-inflammatory benefit to protect patients as well, in terms of secondary prevention. We also know from primary prevention that patients with inflammatory disease such as lupus, or psoriasis, or HIV, even Crohn's disease, causes increased risk of cardiovascular disease due to increase inflammatory effect.

At this time, I don't really see aspirin going out the door for secondary prevention. So, I do think we can stick to the motto, "An Aspirin a day will keep the doctor away, for some people". But I think it's important for patients not to just take it because they think it's the right thing to do. I think maybe down the road, there'll be a better antiplatelet agent than aspirin or something comprehensive, but I think we're understanding more about the processes of preventing secondary events and certainly we'll learn more about preventing primary prevents. On the primary side, it's always about the risk factors. So, it's exciting times in cardiology. Knowledge is power and I think patients now are seeking out more knowledge on this particular topic.