Have you heard about the United States Preventive Services Task Force (USPSTF) official announcement that patients over 60 years old are advised against starting aspirin to prevent heart disease? The April 2022 advisory states that people over 60 years old who do not have any previous history of cardiovascular disease should not start taking low-dose aspirin in order to prevent a future heart attack or stroke.
The formal recommendation states, “The USPSTF recommends against initiating low-dose aspirin use for the primary prevention of cardiovascular disease (CVD) in adults 60 years or older.” But before you toss your bottles of low-dose aspirin in the trash, let’s first find out if this applies to you.
Understanding the difference between primary and secondary prevention
There’s an important distinction between “primary prevention” and “secondary prevention”. Primary prevention is an intervention or action that is designed to prevent the first event from happening. So if you don’t have known heart disease or stroke but you would like to do something to keep from ever getting these cardiovascular diseases (CVD), then you would want to use primary prevention.
However, if you already have had coronary artery disease (suffered “angina” or have had a stent or bypass surgery) or you have had a prior clot in your brain (ischemic stroke) and you would like to avoid further heart disease or stroke problems, then you would use “secondary prevention” tactics. Because having a history of cardiovascular disease markedly increases your risk of having another, secondary stroke or worsening of coronary artery disease. You are more likely to have a benefit (versus a risk) from doing something that lessens your chance of further disease occurrence.
Because aspirin has risks of bleeding (in the stomach, the brain, or elsewhere), the benefit associated with prevention needs to be great enough to outweigh the bleeding risk. In patients over 60 years, with no history of CVD, the chance of having a CVD event is lower than the risk of bleeding. In patients over 60 years with a prior known history of CVD who are at higher risk of having a second CVD event, the benefit of decreasing the likelihood of CVD outweighs the risk of having a serious bleed.
Evaluating the benefits and risks to provide general health and medical recommendations
Every recommendation in medicine reflects a balance between the benefit one hopes to gain from intervention and the risk of suffering an adverse effect from that intervention. The recommendations on a population level are formed by groups of experts who have looked at millions of data points to determine the likelihood of benefit versus the risk.
In the last two decades, many of our official recommendations have been based on huge trials with lots of carefully-screened participants. The amount of benefit and risk is weighed, and the experts decide if the benefits are significantly greater than the risks, and make their recommendations accordingly.
Because people vary and situations are not completely applicable to everyone, there are population-level recommendations that we tend to use to advise our patients. Several factors go into figuring out the benefits and the risks including:
- the characteristics of the people enrolled in the original studies (over age 60, with/without known CVD)
- the intervention (dose of aspirin, type of aspirin pill)
- the outcomes looked at (stroke, heart attack, death from CVD, GI bleed, brain bleed)
As you might imagine, the effect on each individual patient cannot be determined with certainty. Almost every medical recommendation is an educated attempt to apply what we know about how similar people responded to similar interventions to an individual’s situation.
For primary prevention, it appears that the risk of bleeding is greater than the benefit of reduction in CVD for patients over 60 years with no history of CVD. Therefore do not start aspirin in an attempt to prevent the first occurrence of CVD.
For secondary prevention, the advice for patients over 60 years is to continue to take low-dose aspirin because these people are a high likelihood of CVD worsening or recurring, and the risk of serious CVD is greater than the risk of bleeding from aspirin.
Please consult with your physician about whether you can safely continue or discontinue the use of aspirin. This decision should be made after a careful review of the risks and benefits of your individual care. If you found this information helpful, please let us know by leaving a comment below.
