Aspirin proves just as effective as blood-thinning injections for surgery patients

COLLEGE PARK, Md. — If you need emergency surgery to repair a bone fracture, doctors will inject you with a blood thinner to prevent blood clots. Now, a groundbreaking clinical trial reveals over-the-counter aspirin is just as effective as injectable blood thinners in preventing clots. The trial, conducted across 21 trauma centers in the U.S. and Canada and involving over 12,000 patients, marks the largest-ever study in orthopedic trauma patients. The findings challenge the current practice of administering heparin as a standard blood clot prevention measure, potentially leading surgeons to switch to aspirin for these patients.

“Many patients with fractures will likely strongly prefer to take a daily aspirin over receiving injections after we found that both give them similar outcomes for prevention of the most serious outcomes from blood clots,” said the study’s principal investigator Robert V. O’Toole, MD, in a university release. “We expect our findings from this large-scale trial to have an important impact on clinical practice that may even alter the standard of care.”

Blood clots pose a severe risk to patients, causing thousands of deaths every year. Individuals who undergo surgery for fractures, estimated to be around one million people annually in the U.S., are particularly susceptible to developing blood clots in their veins, including potentially fatal pulmonary embolisms. Current guidelines recommend low-molecular-weight heparin, but research in other surgical procedures has suggested that aspirin could be a more affordable and accessible alternative.

The clinical trial randomly assigned half of the patients to receive injectable low-molecular-weight heparin twice daily, while the other half received 81 mg of aspirin twice daily. The 90-day follow-up period after surgery revealed that aspirin was on par with heparin in preventing death from any cause. There were no significant differences in non-fatal pulmonary embolism cases, bleeding complications, or other safety outcomes between the two groups. While the heparin group showed slightly fewer blood clots in the legs, the clinical significance of this finding remains uncertain.

These results provide robust evidence that aspirin is a viable option for preventing blood clots and death in orthopedic trauma patients. The implications of this study could lead to a significant shift in clinical practice, benefiting patients by reducing costs and simplifying treatment regimens.

The trial, named PREVENT CLOT (PREVENTion of CLots in Orthopaedic Trauma), was funded by the Patient-Centered Outcomes Research Institute (PCORI). Patients from the University of Maryland Medical Center’s R Adams Cowley Shock Trauma Center and 20 other trauma centers across the U.S. and Canada participated in the study. The research team hopes that these findings will guide surgeons in preventing potentially fatal blood clots after fracture surgeries using a medication that is both cost-effective and easy to administer.

The study is published in the New England Journal of Medicine.

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