Conference Coverage
Adding Clopidogrel to Anticoagulant Is Plenty for PCI
Major Finding: In coronary-stented patients on oral anticoagulation, bleeds occurred in 20% on clopidogrel only and 45% on clopidogrel and aspirin...
SNOWMASS, COLO. – A recent randomized trial provides physicians with important new guidance on how to manage antithrombotic therapy in patients requiring oral anticoagulation who develop an acute coronary syndrome and undergo percutaneous coronary revascularization with stent implantation.
"I think this is one of the most important trials in cardiology published last year. I think it has to rank in the top five," Dr. Patrick T. O’Gara commented at the Annual Cardiovascular Conference at Snowmass.
The trial is WOEST, a Dutch/Belgian multicenter, randomized, open-label study in which 573 such patients were assigned to triple antithrombotic therapy with clopidogrel and aspirin on top of their background warfarin, or to dual therapy with warfarin and clopidogrel.
Dr. Patrick T. O'Gara
The primary outcome was the rate of bleeding during the first year following stent implantation. The rate was 19.4% in patients on double therapy and 44.4% in those on triple therapy, for a highly significant 64% reduction in relative risk favoring the less aggressive antithrombotic strategy. At least one blood transfusion was required during the follow-up period by 3.9% of patients receiving dual therapy, compared with 9.5% of patients on triple therapy (Lancet 2013;381:1107-15).
"The more than twofold excess risk of bleeding in patients treated with triple versus double antithrombotic therapy is not a surprise. What was a surprise in this particular study was that a secondary endpoint of death/MI/stroke/target vessel revascularization/stent thrombosis was also higher in the triple-therapy group," said Dr. O’Gara, professor of medicine at Harvard Medical School and director of clinical cardiology at Brigham and Women’s Hospital, Boston.
Indeed, the rate of this composite endpoint was 17.6% with triple therapy, compared with 11.1% with double therapy, for a 40% relative risk reduction.
"This study implies that the use of clopidogrel and a vitamin K antagonist is not only safer but actually might be more efficacious than a strategy of triple antithrombotic therapy following stent deployment," observed Dr. O’Gara, the American College of Cardiology (ACC) president-elect.
"Obviously this will need to be validated in other groups, and the sample size here is relatively small at under 600 patients, but this study has set the standard against which we need to design future trials and begin to make some clinical decisions. I think this gives us a great deal of cover with the use of clopidogrel plus warfarin after PCI [percutaneous coronary intervention] in patients, particularly in those in whom you think the risk of recurrent stroke is relatively low," according to the cardiologist.
Dr. O’Gara, who chairs the ACC/American Heart Association STEMI Guideline Writing Committee, predicted the committee will take a close look at WOEST when it meets this spring to adjudicate revisions in the 2013 guidelines.
WOEST was funded by Dutch and Belgian research foundations. Dr. O’Gara reported having no financial conflicts.