MIAMI BEACH – Recommendations to stop taking aspirin therapy 7-10 days before surgery aren’t optimal for everyone, according to several experts who sought to tease out the best approach for multiple clinical scenarios given the lack of data on the issue.
Yet many clinicians have reservations about continuing aspirin perioperatively because, unlike other antiplatelet agents, it irreversibly inhibits platelet cyclooxygenase. In other words, once a platelet is inhibited by aspirin, the effect lasts for the 7-10 days it takes the body to replace circulating platelets.
Dr. Amir Jaffer
As a result, most low-risk patients who are taking aspirin therapy for primary prevention of cardiovascular disease currently are advised to stop taking it 7 to 10 days before surgery," said Dr. Amir Jaffer, chief of the Division of Hospital Medicine and member of the medicine faculty at the University of Miami. New guidelines from the American College of Chest Physicians shore up that practice by advising an interruption of an aspirin regimen 7-10 days prior to major or minor surgery if the patient is at lower risk (Chest 2012;141:e326S-50S).
But such a blanket recommendation isn’t necessarily the best approach for every patient taking therapy for primary prevention, according to Dr. Jaffer and others at the meeting. Instead, aspirin should in many cases probably be continued perioperatively at least for some of the time.
Changing practice is a systems issue, he added. "We need to get all the stakeholders together and create an algorithm or guideline so you can keep patients on their aspirin at the time of surgery."
It should be noted that the ACCP guidelines recommend continuing aspirin prior to major or minor surgery if the patient is at higher risk for cardiovascular events and taking the agent as a means of secondary prevention.
In a separate presentation, Dr. Steven L. Cohn said that "3-5 days before surgery may be the most ideal for stopping aspirin if you are going to stop it at all." He added, "Try to continue aspirin as much as possible."
It comes down to balancing the potential for perioperative bleeding with the risk for potential rebound clotting effects after aspirin withdrawal, said Dr. Cohn, director of the University of Miami Hospital Medical Consultation Service and professor of medicine at the University of Miami.
And given the paucity of great evidence on the issue, it makes sense to consider expert consensus, Dr. Cohn said. For example, continue aspirin for minor surgery, according to an international consensus paper (Thromb. Haemost. 2011;105:743-9).
In the setting of primary prevention, stop aspirin 5 days before surgery. Continue aspirin for secondary prevention except if surgery is to take place in a closed space or a major bleeding complication is anticipated (in those cases, stop 5 days before surgery and restart in a stable patient 24 hours postoperatively), he said.
Experts at the meeting also agreed that elective surgery should be delayed for patients on a dual agent regimen. If the surgery is semi-elective or urgent, "you may need to prematurely stop one of the agents," Dr. Cohn said. In the case of emergency surgery, "you won’t have a choice." Have platelets available for transfusion during emergency procedures, these experts recommend.
Dr. Kurt J. Pfeifer also outlined the benefits and risks of perioperative aspirin continuation and offered advice on optimal dosing.
There is stronger evidence of aspirin’s benefits outside the perioperative setting, Dr. Pfeiffer said. However, data to support continuation of aspirin perioperatively include a decrease in incidence of intra- and postoperative stroke (grade 1A evidence, ACCP guidelines); peripheral arterial disease (Br. J. Surg. 2001;88:777-800); and myocardial infarction and other major cardiovascular events (Br. J. Anaesth. 2010;104:305-12).
Stent thrombosis risk is clearly increased when you withdraw aspirin therapy in patients, said Dr. Pfeifer, an attending in Perioperative and Consultative Medicine at Froedtert Hospital and member of the medicine faculty at the Medical College of Wisconsin, Milwaukee.
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Recommendations to stop taking aspirin before surgery aren’t for everyone.
The risk is further elevated if patients have renal insufficiency, diabetes mellitus, or multiple stents. In contrast, the risk is lower for patients on dual clopidogrel-aspirin therapy who discontinue clopidogrel only preoperatively, he added.
The incidence of thrombosis ranges up to 15% within 90 days of stent placement to about 1% of drug-eluting stents up to 1 year (J. Am. Coll. Cardiol. 2007;49:734-9).
"Even though it’s 1%, up to 45% die, so it’s a big deal," Dr. Pfeifer said.
The risks related to in-stent thrombosis obviously also differ based on location of the stent, Dr. Pfeifer said. Risks for myocardial infarction and death are elevated with cardiac stents, for example. Occlusion at other sites can be serious as well, he added, "but you have more time to do something."