Landmark clinical study: aspirin is as effective as commonly used blood thinners

Patients undergoing fracture repair surgery typically receive an injectable blood thinner, low molecular weight heparin, to prevent life-threatening blood clots, but a new clinical trial has found that over-the-counter aspirin is just as effective
.
The findings, presented today at the annual meeting of the Society for Plastic Trauma (OTA) in Tampa, Florida
, may prompt surgeons to change their practice and give aspirin to these patients.

This multicenter randomized clinical trial studied more than 12,000 patients at 21 trauma centers in the United States and Canada, and is the largest for orthopedic trauma patients to
date.
The trial was co-led
by the Department of Orthopedics at the University of Maryland School of Medicine (UMSOM) and the Major Limb Trauma Research Consortium (METRC) at the Johns Hopkins Bloomberg School of Public Health.

Robert V.
O'toole, M.
D.
, lead researcher of the study, said, "We hope that what we have found from this large-scale trial will have important implications for clinical practice and may even change the standard of
care.
" Robert V.
O'toole, M.
D.
, is the Hansjörg Weiss Medical Foundation's Professor of Orthopaedic Trauma at UMSOM and head
of the school's Department of Orthopaedic Traumatology.
"Orthopedic trauma patients are often prescribed the blood thinner low molecular weight heparin to prevent thrombosis in
the weeks after surgery.
Not only does this drug require injections, but it is also quite expensive
compared to aspirin.
”

According to the Centers for Disease Control (CDC), blood clots cause up to 100,000 deaths
each year in the United States.
An estimated 1 million fractures in the United States each year who require surgery have an increased risk of developing blood clots in the veins, including fatal pulmonary embolism, or blood clots
in the lungs.
Current guidelines recommend prescribing low molecular weight heparin (enoxaparin), although studies of total joint replacement have shown the potential benefits
of aspirin as a cheaper, broader option.

Dr.
O'toole, who is also the director of orthopedics at the University of Maryland Medical Center (UMMC) R Adams Cowley Shock Trauma Center, presented the results of
this landmark clinical trial at the OTA Annual Meeting.
The $12 million study was funded by the Patient-Centered Outcomes Institute (PCORI) (PCS-1511-32745), an independent, nonprofit organization that funds research to help patients and clinicians make more informed health care decisions
.

The study enrolled 12,211 patients with leg or arm fractures that required surgery or pelvic fractures
regardless of specific treatment.
Half of them were randomly assigned to receive 30 mg of injectable low molecular weight heparin
twice daily.
The other half took 81 mg of aspirin twice a day
.
Postoperative follow-up for 90 days
.

The main finding of the study was that aspirin was "no worse" or "not worse" than low molecular weight heparin in preventing death from any cause — 47 patients in the aspirin group died compared to 45 patients in
the heparin group.
Secondary outcomes did not differ
in non-fatal PE.
The incidence of bleeding complications and all other safety outcomes were similar
in both groups.
One potential difference worth noting in all the findings was that there were fewer
blood clots in the legs in the low molecular weight heparin group.
This relatively small difference is caused by clots in the lower part of the leg, but the clinical significance is unclear
.

Andrew Pollak, M.
D.
, said: "Based on data from more than 12,000 patients, this study provides clear evidence that aspirin is a viable option
for preventing lung thrombosis and death in patients requiring surgery due to orthopedic trauma.
" Andrew Pollack is the James Lawrence Knan Professor and Chair of the Department of Orthopaedics at UMSOM and Senior Vice President and Chief Clinical Officer
of the University of Maryland Health System (UMMS) at 11 hospitals.

This test is called prevention of blood clots in orthopedic trauma, or prevention of blood clots
.
Patients enrolled in the trial were treated
at UMMC's R Adams Cowley Shock Trauma Center and 20 other trauma centers in 15 states, as well as 2 trauma centers in Canada.
Recruitment started in April 2017 and continues until 2021
.
Deborah Stein, MD, M.
P.
D.
, M.
P.
, PROFESSOR OF SURGERY AT UMSOM AND DIRECTOR OF ADULT INTENSIVE CARE SERVICES AT UMMC, AND Renan Castillo, PhD, associate professor of health policy and management at the Johns Hopkins Bloomberg School of Public Health, are co-principal investigators
.

Mark T.
Gladwin, M.
D.
, vice chancellor for medical affairs at the University of Maryland, Baltimore, and John Z.
and Akiko K.
Bowers Distinguished Professor and Dean of the University of Maryland School of Medicine, said, "This exciting trial, the largest ever conducted in orthopedic trauma patients, provides surgeons with important guidance to help them prevent potentially fatal blood clots after fracture surgery by using a drug that is both inexpensive and easy to manage
。 ”