Not the worst, the WOEST trial is my pick for most influential at ESC 2012

Dr John Mandrola


August 30, 2012

In the immediately actionable category, one study won handily. Despite having perhaps the worst acronym, the WOEST trial (What is the Optimal Antiplatelet and Anticoagulant Therapy in Patients with Oral Anticoagulation and Coronary Stenting) will surely alter the practice of both electrophysiologists and interventionalists alike.

It's an increasingly common scenario. When patients already taking anticoagulation undergo coronary stenting, doctors are faced with a difficult situation. They must expose their patients to "triple therapy" with clopidogrel, aspirin, and warfarin. That's a lot of anticoagulation and bleeding risk, especially in high-risk patients.

I dislike this scenario immensely. It makes me worry about harm. Until ESC 2012, there was little choice. Interventionalists insist on antiplatelet regimens to prevent stent thrombosis, and electrophysiologists point to the importance of anticoagulants for stroke prevention in AF. Neither regimen alone is adequate.

That's all changed now. For a thorough and concise review of WOEST, including a video interview with a primary investigator, see Sue Hughes's review on . In short, WOEST investigators dared to ask the important question: Would it be safe to drop aspirin and "downgrade" to double therapy with clopidogrel and warfarin?

It was.

The three most important findings:

  • Double therapy significantly reduced bleeding, although this difference was mostly driven by minor (skin) bleeding.

  • Double therapy did not increase the risk of stent thrombosis. On the contrary, in fact, the actual numbers—not statistically significant—showed fewer events with double therapy.

  • Double therapy did not increase the risk of stroke and MI. Again, paradoxically, these important outcome measures were numerically less with double therapy.


Three slight notes of caution: The trial enrolled only 573 patients who were followed for just a year. Two-thirds of the patients had drug-eluting stents, so longer-term follow-up would be more reassuring. Another notable was that minimal-minor bleeds involving the skin, rather than major bleeding events, drove the results. Finally, WOEST did not study the new anticoagulants. We can't say how these new drugs will work in combination with clopidogrel and aspirin.

Take home:

In yet another example of less being more, the WOEST trial tells us that dropping aspirin, "downgrading" to double therapy, significantly decreases the risk of bleeding without jeopardizing the risk of stent thrombosis, MI, or stroke.

These are important findings. They will change our practice immediately. Look for guidelines to change as well.



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