Local researchers changing the game

Dr. Dunbar and Dr. Anderson
Dr. Dunbar (left) and Dr. Anderson (submitted).

A Nova Scotia Health Authority, QEII Health Sciences Centre physician, in partnership with Dalhousie University Dean of Medicine and Dalhousie and NSHA researchers, are changing the way we prevent blood clots (venous thromboembolism) after hip and knee replacement surgery.

Dr. David Anderson’s (Dalhousie University Dean of Medicine) and Dr. Michael Dunbar’s (NSHA Orthopedic Surgeon, Researcher and QEII Foundation Endowed Chair in Arthroplasty Outcomes) study, published in the New England Journal of Medicine, found that there were no significant differences between widely available and inexpensive Aspirin and the current standard prescription drug (called Rivaroxaban) used to prevent blood clots after total hip or total knee arthroplasty.

Dr. Dunbar said the study’s findings should improve patient safety and make it easier for patients to take medication to prevent post-surgery blood clots.

“Blood clots are an uncommon but potentially serious complication after hip and knee replacement surgery… [and] some form of prophylactic medicine is required. The presently recommended medications can be difficult to comply with because of the need to monitor blood levels frequently, the potential need for the patient to inject themselves daily, or the potential for bleeding complications,” he said. “Aspirin is an attractive alternative but until this study has not had definitive proof of efficacy and safety in this population. The use of aspirin for extended prophylaxis after a short course of rivaroxaban should improve patient compliance and overall safety for patients.”

Research teams at NSHA completed an interdisciplinary study between orthopaedics and haematology. The study was a joint effort conducted at 14 other institutions across several provinces (NS, ON, QC, NB, MB) and many participating sites commended NSHA Hematology Research Manager Susan Pleasance and her team on their excellent study management. Nova Scotia Health Authority's Research Methods Unit (RMU) contributed with sample size calculation, analytic design and results analysis. They also contributed to data management activities of the study, including database consulting and design, data reporting, data cleaning and preparation for analysis.

An editorial published shortly after the study’s findings were shared said that the results are practice-changing and a new strategy to prevent blood clots in knee and hip replacement patients.

Dr. Dunbar said surgeons work to create a balance between blood clots and significant bleeding after surgery and the results of this study establish that.

“Surgeons have been hoping that a simple agent, like aspirin, could be proven effective and safe for the prevention of blood clots after hip and knee surgery because of its ease of administration and known side effect profile,” said Dr. Dunbar. “This large, multi-centre, randomized control trial on an inclusive cohort of patients provides a new benchmark for research in this field.”

Editors note: Edited and condensed from NSHA Research in Progress.