Patients with atrial fibrillation (AF) on anticoagulation therapies who require a surgical procedure may require an interruption in the therapy – depending on their risk of post-procedural bleeding and the likelihood of periprocedural thrombotic events. According to an analysis of data from the ARISTOTLE trial, though, many patients were able to undergo surgical procedures safely without interrupting or bridging therapy.
"These findings corroborate the implications of many other studies," lead author David Garcia, MD, of the division of hematology, University of Washington, Seattle, told ASH Clinical News. "In 2014, for patients with atrial fibrillation, pre-procedure parenteral bridging therapy looks increasingly unnecessary."
The ARISTOTLE trial compared apixaban (an oral direct factor Xa inhibitor) with warfarin for the prevention of stroke or systemic embolism in AF patients. Apixaban, in contrast to warfarin and other vitamin K antagonists, has a rapid onset and offset of anticoagulant activity – making it an attractive option for patients who require short-term protection from thrombosis before a surgical procedure. According to Dr. Garcia, physicians have more experience with managing patients taking warfarin who require surgical procedures than the newer target-specific oral anticoagulants.
In this analysis, investigators explored the management of anticoagulants and surgical outcomes 30 days post-procedure among 5,924 patients from the ARISTOTLE study who underwent a total of 10,674 procedures. Overall, 5,439 patients had a procedure that met study eligibility criteria. The most common were dental extraction/oral surgery (14.6%), colonoscopy (9.9%), and ophthalmic surgery (8.0%).
Local investigators chose to interrupt anticoagulant treatment pre-procedure in 62.5 percent of patients; the duration of pre-procedure interruptions were comparable between the apixaban and warfarin arms. Of all included patients and procedures, 11.7 percent received some form of bridging anticoagulation either before or after the procedure.
Post-procedure stroke or systemic embolism occurred in 0.35 percent of patients in the apixaban-treated arm and in 0.57 percent of patients in the warfarin-treated arm (odds ratio [OR] = 0.601; 95% CI 0.322-1.120). Major bleeding occurred in 1.62 percent of the procedures in the apixaban-treated arm and 1.93 percent of procedures in the warfarin-treated arm (OR = 0.846; 95% CI 0.614-1.166).
Overall, the post-procedure stroke, death, and major bleeding rates were low and similar in apixaban- and warfarin-treated patients, the researchers concluded, regardless of whether anticoagulation was stopped beforehand. The overall risk for death within 30 days post-procedure was 1.17 percent with apixaban and 1.08 percent with warfarin. Similar numbers of patients in the apixaban arm died within 30 days whether or not anticoagulation treatment was interrupted. In contrast, in the warfarin arm, the rate of 30-day all-cause mortality was 0.5 percent for patients with anticoagulation interruption and 2.0 percent for those without interruption prior to their procedure.
"If your patient with atrial fibrillation is taking apixaban or warfarin and needs a procedure, it is possible that he or she can undergo the intervention without any interruption of therapy beforehand," Dr. Garcia said. "If interruption is deemed necessary – and it will be for many patients and procedure types – withholding anticoagulation for a short time without bridging anticoagulation is likely to be safe."
When discussing examples of procedures for which anticoagulants may not need to be interrupted, Dr. Garcia noted that one of the challenges of this study was that the interruption patterns were not standardized as part of the ARISTOTLE trial protocol. "Since the decision whether, and for how long, to interrupt study medication was left to the local investigator, our analysis does not define specific procedures for which interruption is not necessary," Dr. Garcia said. "That being said, there are evidence-based guidelines that recommend continuing anticoagulant therapy for many dental procedures and other minor surgeries."
- Garcia D, Alexander JH, Wallentin L, et al. Management and clinical outcomes in patients treated with apixaban versus warfarin undergoing procedures. Blood. 2014 October 15. [Epub ahead of print]