Reducing aspirin use in patients treated with common blood thinners prevents bleeding complications

If you’re already taking a blood thinner, increasing research suggests you may not need to take a second dose.

In fact, when patients who commonly take blood-thinning medications stop taking aspirin, their risk of bleeding complications drops dramatically, a Michigan Medicine study found.

Researchers analyzed more than 6,700 people treated at anticoagulation clinics across Michigan for venous thromboembolism, as well as atrial fibrillation, a heart rhythm disorder that can cause stroke. The patients were treated with blood-thinning warfarin but also took aspirin despite having no history of heart disease.

We know that aspirin is not a panacea as previously thought and can actually lead to more bleeding in some of these patients, so we’ve worked with clinics to reduce aspirin use among patients for whom it may not be necessary. . “

Jeffrey Barnes, MD, senior study author and cardiologist at the University of Michigan Frankel Cardiovascular Center

During the study period, aspirin use among patients decreased by 46.6%. With less common use of aspirin, the risk of bleeding complications decreased by 32.3% -; It represents one major bleeding event prevented for every 1,000 patients who stop taking aspirin. The results are published in . format JAMA Network is open.

“When we started this study, there was already an effort by clinicians to reduce aspirin use, and our findings showed that accelerating this reduction prevents serious bleeding complications which in turn could save patients’ lives,” Barnes said. Associate Professor of Internal Medicine at UM College of Medicine. “It’s really important for clinicians and health systems to be more aware of when patients with blood clots should and shouldn’t use aspirin.”

This decline in aspirin use is based on the many studies that have found regarding links between concurrent use of aspirin and various blood thinners.

One study reported that patients taking warfarin and aspirin for atrial fibrillation and VTE experienced more major bleeding episodes and had more ER visits for bleeding than those taking warfarin alone. Similar results occurred for patients who took aspirin and direct oral anticoagulants – who were found to be more likely to bleed but not less likely to develop a blood clot.

“While aspirin is a very important drug, its role is less frequently used than it was a decade ago,” Barnes said. “But with each study, we see that there are far fewer cases where patients who are already taking anticoagulants see a benefit by adding aspirin on top of this treatment. And the blood broth they are taking actually provides some protection from clot formation.”

For some people, aspirin can be a life saver. The drug benefits many patients with a history of stroke or heart attack or a stent placed in the heart to improve blood flow – as well as those with a history of cardiovascular disease.

The challenge comes when some people take aspirin without a history of cardiovascular disease them too It was described by first author Jordan Schaefer, MD, a hematologist at UM Health and clinical assistant professor of internal medicine at UM College of Medicine.

“A lot of these people were probably taking aspirin for primary prevention of heart attacks or strokes, which we now know is less effective than previously thought, and no one turned away from it when they started warfarin,” Schaefer said. “These results show how important it is to only take aspirin under your doctor’s supervision and not start taking over-the-counter medications like aspirin until you’ve reviewed it with your care team if the expected benefit outweighs the risks.”


Journal reference:

Schaefer, J.K., and others. (2022) Evaluation of an intervention to reduce prescribing aspirin to patients receiving warfarin for anticoagulation. JAMA Network is open.