Antiplatelet treatment in patients on long-term anticoagulation

Dr Matthew Sibbald is an associate professor in the Division of Cardiology at McMaster University and interventional cardiologist at Hamilton Health Sciences.

What is the best approach to antiplatelet treatment in patients on long-term anticoagulation?

Matthew Sibbald, MD, MHPE, PhD: Certainly, we have been challenged with this group of patients who are at risk of stroke, need anticoagulation, and sometimes on top of that require 2 antiplatelet agents because they have had a heart attack or stents placed.

Traditionally, we would give these patients all 3 blood thinners: aspirin, clopidogrel, and warfarin. The challenge here is they have a lot of bleeding, which is up to 40% in some trials. Fortunately, we have had now probably 4 randomized trials in the last 5 or 6 years that compared less intensive regimens and have all found substantial benefits in bleeding reduction.

The strategy nowadays is to minimize the time that we leave patients on triple therapy. Most of the time that means dropping aspirin. The most recent trial, AUGUSTUS, compared aspirin versus no aspirin in patients who had stents and needed anticoagulation for stroke. They found no increased event rates related to myocardial infarction (MI) or stent thrombosis and reduced bleeding when aspirin was dropped. It also compared, in a crossed design, warfarin versus a direct oral anticoagulant—apixaban—and found reduced bleeding with the direct oral anticoagulant, which seems to be a theme in all of these trials.

So the recommendation is to use as little triple therapy as possible: up to just a day when a stent is implanted and up to 6 months if you feel that the patient has a higher risk of stent thrombosis or heart attacks, combined with an oral anticoagulant—preferably a direct oral anticoagulant rather than warfarin because of its lower rate of bleeding.