Major Study Offers Insights into Making Surgery Safer for Patients Taking Direct Oral Anticoagulants (DOACs)
A Hamilton-led international study of more than 3,000 patients could set the stage globally for how patients can safely use blood-thinning medications before and after surgery to mitigate risk of bleeding and stroke.
The 4-year study found that a simple, standardized approach for minimizing risks in patients taking direct oral anticoagulants (DOACs) who required a surgery or procedure was associated with low rates of bleeding and stroke during and after surgery.
Dr. James Douketis led the Perioperative Anticoagulation Use for Surgery Evaluation (PAUSE) study, conducted across 23 clinical centres in Canada, the United States, and Europe. Dr. Douketis is a physician-researcher at St. Joseph’s Healthcare Hamilton and Professor in the Department of Medicine at McMaster University.
“Previously, there was no standard approach for patients taking DOACs who required an elective surgery or medical procedure,” said Dr. Douketis. “The PAUSE study tested an approach in patients with atrial fibrillation, who are the most frequent users of DOACs. The study aimed to balance the benefits of DOACs in preventing blood clots with the risk of bleeding around the time of a surgical procedure.”
Commonly known as blood thinners, DOACs are medications used to prevent blood clots from forming or growing. They are typically prescribed to patients with atrial fibrillation, where an irregular heartbeat can cause blood to collect in the heart and form a clot. Current DOAC medications include apixaban (Eliquis®), dabigatran etexilate (Pradaxa®), and rivaroxaban (Xarelto®), among others.
While studies have shown DOACs to be more effective at preventing blood clots compared to warfarin, this relatively new class of drug has raised concerns during surgical procedures when their blood-thinning effects can lead to a higher risk of bleeding. Unlike warfarin, an older blood thinner that can be easily counteracted with vitamin K, DOACs do not have a countermeasure capable of reversing their effects.
“When we began the PAUSE study in 2014, it was estimated that over 2 million people in North America receiving DOAC therapy would need a surgical procedure each year,” noted Dr. Douketis. “Knowing when to stop and restart these drugs is important so that the risk to a patient of developing bleeding or a stroke is minimized.”
The PAUSE study saw researchers testing an approach that included a guided interruption to patients taking a DOAC, followed by a resumption of DOAC therapy after surgery. The approach can be summarized as not taking the DOAC medication for 1 day before and after procedures associated with a low bleeding risk, and 2 days before and after a high bleeding risk procedure. This simple approach was easy to follow by patients and health care professionals, with over 95 percent adherence. Patients were monitored for 30 days after their procedure.
Dr. Douketis with Mary Ann, a patient at St. Joseph's Healthcare Hamilton who takes a DOAC
The study also found that by stopping DOAC medication shortly before surgery, their residual anticoagulant levels dropped to an optimal level to perform surgery, without the need for heparin bridging.
The findings were published today in JAMA Internal Medicine.
“The significance of these findings cannot be understated – they will help inform perioperative guidelines for patients taking DOACs around the world,” said Dr. Jack Gauldie, Vice President of Research at St. Joseph’s Healthcare Hamilton. “The PAUSE study is yet another example of the global impacts coming out St. Joe’s and McMaster, Canada’s most research-intensive university.”
Funding for the study, which totaled over $4 million, was provided by grants from the Canadian Institutes of Health Research and the Heart and Stoke Foundation of Canada.
Hematology research at St. Joseph’s Healthcare Hamilton is conducted within the Father Sean O’Sullivan Research Centre, the largest group at the Research Institute of St. Joe’s.