By Crystal Phend, Senior Staff Writer, MedPage Today
Patients taking aspirin or warfarin (Coumadin) for prevention after a stroke don’t need to stop the drug for dental procedures and probably can stay on it for most other minor medical procedures, the American Academy of Neurology recommended.
Prostate or hernia procedures, electromyography, and saphenous vein ablation might be candidates for continued warfarin or aspirin, according to the guidelines published in the May 28 issue of Neurology.
Heparin bridging to reduce stroke risk for patients who do go off chronic warfarin therapy before their surgery doesn’t clearly help and might harm, Melissa J. Armstrong, MD, of the University of Maryland in Baltimore, and colleagues on the writing committee cautioned.
“Neurologists should counsel that bridging therapy is probably associated with increased bleeding risks as compared with warfarin cessation,” they wrote. “The risk difference as compared with continuing warfarin is unknown.”
Two trials recently vindicated continuation of warfarin versus heparin bridging during atrial fibrillation ablation and during pacemaker implantation or related procedures, but the neurology guidelines didn’t cover any procedures related to the heart.
“It’s always a matter of balancing the risk and benefit,” Armstrong told MedPage Today in an interview. “There’s risk involved with stopping the drug — having another stroke — and with not stopping, that’s bleeding.”
Bleeding tends to be relatively mild in terms of outcomes whereas morbidity and mortality is high for thromboembolic events that occur during breaks in antithrombotic therapy, her group noted.
While high-quality evidence is lacking, what studies are available suggest a 97% increased thromboembolic risk after stopping aspirin for 2 weeks and a 5.5-fold elevated risk from stopping warfarin for a week or more.
“To minimize this risk, it seems reasonable to minimize the duration of antithrombotic discontinuation,” the guidelines pointed out.
Chronic use of both drugs has been estimated to have an antithrombotic duration of 7 days; a single dose lasts about 2 to 5 days.
If aspirin is going to be stopped for a procedure, the general recommendation is doing so for 7 to 10 days beforehand; 5 days prior to the procedure for warfarin.
The best evidence in favor of routinely continuing aspirin and warfarin was in dental procedures, where research has shown the drugs “highly likely not to increase bleeding risk.”
Aspirin and warfarin should “probably” be continued due to not being likely to increase bleeding risk in invasive ocular anesthesia and dermatologic procedures.
The same recommendation was made for aspirin in the case of:
- Cataract surgery
- Transrectal ultrasound-guided prostate biopsy
- Spinal or epidural needle procedures
- Carpal tunnel syndrome surgery
Staying on aspirin is “possibly” reasonable for some stroke patients getting vitreoretinal surgery, electromyography, transbronchial lung biopsy, colonoscopic polypectomy, upper endoscopy and biopsy or sphincterotomy, and abdominal ultrasound-guided biopsies, the guidelines added.
The same was argued for warfarin in electromyography, prostate procedures, inguinal herniorrhaphy, and endothermal ablation of the great saphenous vein. Warfarin might increase bleeding risk with colonoscopic polyp removal and possibly should be discontinued for that procedure.
Other eye procedures might be safe to do without stopping antithrombotic medication as well, but the studies just haven’t had enough statistical precision for recommendations, Anderson’s group wrote.
“There’s a lot of information we don’t know,” Anderson said in acknowledging limitations of the guidelines.
The recommendations didn’t touch clopidogrel (Plavix) or newer anticoagulants and shouldn’t be extrapolated to those agents, she cautioned.