Largest-ever study to compare medications to prevent life-threatening clots in orthopaedic trauma patients

To reduce the risk of these clots, doctors have for years prescribed low molecular weight heparin, a blood thinner, to many fracture patients. Is that the most effective option? Some researchers argue that aspirin may be just as effective at preventing clots in these patients.

A comprehensive new study led by researchers at the University of Maryland School of Medicine (UM SOM) will try to resolve this important question. The five-year, $11 million project will partner with 10 other trauma centers around the country and will include 13,000 patients, all of whom have suffered fractures. It will be the largest study of this question ever undertaken.

"This is an important question, and we just don't know the answer," said Robert V. O'Toole, MD, the Hansjörg Wyss Medical Foundation Endowed Professor in Orthopaedic Trauma, at UM SOM, head of the school's Division of Orthopaedic Traumatology and Chief of Orthopaedics for the University of Maryland Medical Center's R Adams Cowley Shock Trauma Center.

"I think this study, with its depth and breadth, will go a long way toward giving us useful information that will help us treat patients more safely and effectively," added Co-Principal Investigator on the study Deborah Stein, MD, the Chief of Trauma at the R Adams Cowley Shock Trauma Center.

Half of the patients will receive injectable low molecular weight heparin, while the other half will receive aspirin. While aspirin can be taken as a pill, low molecular weight heparin must be injected.

The researchers will seek to establish which approach works better at preventing clots and reducing deaths from clots. They will also look at whether one medicine is linked to fewer complications that require further treatment for the fracture. Some researchers suspect that low molecular weight heparin may be associated with surgical complications and increase bleeding more than is necessary, but this is currently not proven.

Overall, blood clots cause about 300,000 deaths in the U.S. annually. Injuries that break certain bones, like the hip or thigh bone, which are common, are also associated with a high risk of clots. The issue is complicated because medications to prevent blood clots can also increase the risk of bleeding or other complications from the fracture.

The research will be funded by the Patient-Centered Outcomes Research Institute (PCORI), an independent, nonprofit organization authorized by Congress in 2010. Its mission is to fund research that will provide patients, their caregivers, and clinicians with the evidence-based information needed to make better-informed healthcare decisions.

"This project was selected for PCORI funding not only for its scientific merit and commitment to engaging patients and other stakeholders, but also for its potential to fill an important gap in our health knowledge and give people information to help them weigh the effectiveness of their care options," said PCORI Executive Director Joe Selby, MD, MPH. "We look forward to following the study's progress and working with Dr. O'Toole and his colleagues to share the results."

The study will be managed in partnership with the Major Extremity Trauma Research Consortium (METRC, www.metrc.org), centered at the Johns Hopkins Bloomberg School of Public Health. The participating hospitals include the University of Maryland's R Adams Cowley Shock Trauma Center, Carolinas Medical Center, Harborview Medical Center, Indiana University Health Methodist Hospital, Massachusetts General Hospital, Rhode Island Hospital, San Antonio Military Medical Center, University of Pittsburg Medical Center, University of Texas Health Sciences Center at Houston, Vanderbilt University Medical Center and Wake Forest Health Sciences.

"Once again, our researchers are leading the way both scientifically and clinically," said UM SOM Dean E. Albert Reece, MD, PhD, MBA, who is also vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor. "This study is a fantastic example of cutting-edge 21st century research, combining multiple specialties -- orthopaedics, trauma care, and cardiovascular medicine -- in innovative, ambitious ways. I look forward to seeing the results."