February 14th, 2013

No Aspirin After DES? Is This The Wild, Wild WOEST?


Some patients referred for coronary stenting have atrial fibrillation or a mechanical valve, for which they are receiving chronic anticoagulation.  Typically, dual antiplatelet therapy (with aspirin and clopidogrel) is prescribed to prevent stent thrombosis, but the combination of chronic anticoagulation and dual antiplatelet therapy is associated with a high risk (4–16% annually) for fatal and nonfatal bleeding.  We’re “shooting from the hip,” since we don’t really know the optimal treatment after coronary stenting in these patients. 

To address this issue, the WOEST (What is the Optimal antiplatElet and anticoagulation therapy in patients with oral anticoagulation and coronary StenTing) investigators randomly assigned 573 adults receiving anticoagulation and undergoing PCI to (a) clopidogrel alone (double therapy) or (b) clopidogrel plus aspirin (triple therapy); one third of the study population received bare-metal stents, and two thirds received drug-eluting stents.  After 1 year of follow-up, the investigators found that double therapy (clopidogrel without aspirin) was associated with a dramatic reduction in bleeding complications and no increase in the rate of thrombotic events when compared with triple therapy


Double therapy (n=297)

Triple Therapy (n=284)

P value

Any bleeding




TIMI bleeding




–          major




–          major and minor








Stent Thrombosis




In short, the results of the WOEST trial show that aspirin is not needed after coronary stenting in chronically anticoagulated patients treated with clopidogrel.  

Although the trial was underpowered to detect a difference in the occurrence of stent thrombosis, no suggestion of increased thrombosis in the patients treated with only double therapy was noted.

What antiplatelet therapy do you prescribe in subjects undergoing coronary stenting who are receiving chronic anticoagulation? 

Based on the results of the WOEST trial, are you willing to prescribe clopidogrel alone to these patients?

(Although just published, the WOEST trial results were previously reported by Larry Husten  after they were presented at the European Society of Cardiology)

3 Responses to “No Aspirin After DES? Is This The Wild, Wild WOEST?”

  1. Stephen Austin, MD says:

    Since this challenges a long established “standard of care,” need more than one study which is underpowered to address the critical issues of stent thrombosis and overall mortality before advocating a widespread change in practice. A large, adequately powered prospective study is necessary, which would also provide insight into risk factor stratification for both stent thrombosis and bleeding.

  2. Stewart Mann, DM (Oxon), FRCP(UK), FRACP says:

    If a “standard of care”, however long-established, is based on assumption with no evidence and an alternative strategy is based on some evidence, albeit incomplete, of better overall outcomes what logic leads to a preference for the first option? I sincerely hope it is not due to a fixation on specific cardiac outcomes at the expense of overall net clinical benefit.

  3. miroslav vytiska, MD says:

    In subjects undergoing coronary stenting who are receiving chronic anticoagulation DES implantation should be avoided.
    When these patients received BMS one month lasting triple therapy is satisfactory and frequency of bleeding is much lower comparing to 12 moths on triple therapy.
    In second generation DES 3 month after stent implantation most struts are covered so DAPT is recommended for 3-6 months.
    Twice higher rate of ST in triple therapy group is surprising although not statistically significant.
    The issue is not only double versus triple therapy but also how long double or triple therapy in patients receiving chronic anticoagulation.