Do Patients on Blood Thinners for Stroke Prevention Need to Stop Them Before Surgical Procedures?
For immediate release: May 28, 2013
University of Maryland Physician Leads Development of New Guidelines from the American Academy of Neurology
People taking blood thinning medicines, such as aspirin or warfarin, to prevent stroke may have an increased bleeding risk during medical procedures. However, if patients who have had a previous stroke stop these drugs prior to a particular procedure, they may increase their risk for another stroke.
This dilemma prompted researchers from the American Academy of Neurology, led by a University of Maryland School of Medicine physician, to conduct a comprehensive analysis examining the risks and benefits of stopping these anti-clotting drugs prior to surgical and medical procedures in at-risk patients. Their new guidelines are published in the May 28, 2013, print issue of Neurology®, the medical journal of the American Academy of Neurology.
“Our analysis found that the risk of bleeding varies depending on the procedure,” explains lead guideline author Melissa Armstrong, MD, assistant professor of neurology at the University of Maryland School of Medicine. “For many minor procedures, such as dental procedures, the increased bleeding risk with these medications is low. However, for certain larger procedures, such as hip and colon procedures, the anti-clotting therapies may increase the risk of bleeding during the procedure.”
“This guideline helps doctors and patients know what the evidence tells us about these different risks, so they can weigh an individual’s health history when deciding whether it is necessary to stop the anti-clotting therapies,” adds Dr Armstrong, who is also a neurologist at the University of Maryland Medical Center.
According to the researchers, millions of Americans may be on these anti-clotting drugs to prevent stroke. These medications are also used to prevent a first stroke in people with atrial fibrillation, an irregular or fast heartbeat. The guideline did not review evidence for people with heart problems other than atrial fibrillation.
The panel of neurologists did an extensive review of scientific studies for the analysis. However, they found most of the research on bleeding risk with these drugs looked at aspirin and warfarin.
“More studies are needed to understand the bleeding risks associated with other blood thinners during and before procedures. These other medications include clopidogrel and aspirin plus dipyridamole, as well as new anticoagulants such as dabigatran, rivaroxaban, or apixaban,” explains Dr. Armstrong.
The analysis found strong evidence that aspirin and warfarin do not increase important bleeding risks during dental procedures and moderate evidence that they do not increase important bleeding risks during dermatological (skin) procedures. Other minor procedures ranging from some eye surgeries to epidural procedures are probably also safe while continuing these drugs, particularly for patients taking aspirin. The researchers found few studies to guide decisions regarding more invasive procedures. They emphasize that all this evidence needs to be balanced with each patient's individual circumstances.
“These new guidelines show the commitment of our University of Maryland School of Medicine faculty to seek out, analyze and apply sound evidence to inform complex medical care. This information will enable clinicians to make the best decisions for their patients who are at risk of a stroke, one of the leading causes of death and disability in the United States,” says E. Albert Reece, M.D., Ph.D., M.B.A., vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor and dean of the University of Maryland School of Medicine.
About the University of Maryland School of Medicine
Established in 1807, the University of Maryland School of Medicine is the first public medical school in the United States, and the first to institute a residency training program. The School of Medicine was the founding school of the University of Maryland and today is an integral part of the 11-campus University System of Maryland. On the University of Maryland's Baltimore campus, the School of Medicine serves as the anchor for a large academic health center which aims to provide the best medical education, conduct the most innovative biomedical research and provide the best patient care and community service to Maryland and beyond. www.medschool.umaryland.edu
About the University of Maryland Medical Center
The University of Maryland Medical Center is an 800-bed teaching hospital in Baltimore and the flagship institution of the 12-hospital University of Maryland Medical System. As a national and regional referral center for trauma, cancer care, neurocare, cardiac care, women's and children's health and physical rehabilitation, UMMC treats patients who are referred nationally and regionally for expertise in time-sensitive critical care medicine. UMMC also has one of the largest solid organ transplant programs in the country, performing 443 abdominal and thoracic transplants in 2012. All physicians on staff at the Medical Center are faculty physicians of the University of Maryland School of Medicine. www.umm.edu