Patients with atrial fibrillation who stopped taking blood thinners before they had elective surgery had no higher risk of developing blood clots and less risk of major bleeding compared to patients who were given a “bridge” therapy, according to research led by Duke Medicine.
The findings add much-needed clarity to inconsistent practice guidelines that annually affect an estimated 250,000 patients with atrial fibrillation/flutter who take the blood thinner warfarin. The Duke-led study was presented June 22, 2015, at the International Society on Thrombosis and Haemostasis meeting and published in The New England Journal of Medicine.
Currently, atrial fibrillation patients are typically told to halt their warfarin for five days before and after they undergo an elective procedure, because it can cause dangerous bleeding and slow healing. After the procedure and resuming warfarin, it may take five or more days before the blood thinner reaches its effective target therapeutic level. To continue protecting them from blood clots during this intermission, many doctors prescribe a low-molecular weight heparin, a faster-acting blood thinner in what is known as a “bridge” therapy.
“Bridging has been controversial because there has been a lack of data demonstrating that it’s necessary, so people don’t know what to do,” said senior author Thomas L. Ortel, M.D., Ph.D, chief of the Division of Hematology at Duke the principal investigator of the Clinical Coordinating Center for the study. The study's Statistical Data Coordinating Center, led by Vic Hasselblad, Ph.D., and the Clinical Coordinating Center were both based at the Duke Clinical Research Institute.
“Bridging does not improve the outcome for stroke prevention, but increases the risk of major bleeding complications,” Ortel said. “That’s the counter balance – we’re not doing patients any good, and we are potentially hurting them.”