What is the Woest (clinical) trial?

The WOEST Trial: Dual vs Triple Therapy in Anticoagulated Patients Undergoing PCI

The WOEST trial demonstrated that dual therapy with warfarin and clopidogrel was associated with significantly fewer bleeding complications compared to triple therapy (warfarin, clopidogrel, and aspirin) in patients requiring oral anticoagulation who underwent coronary stenting, without increasing thrombotic events. 1

Overview of the WOEST Trial

• WOEST (What is the Optimal antiplatElet and anticoagulant therapy in patients with oral anticoagulation and coronary StenTing) was a randomized clinical trial comparing two antithrombotic strategies in patients on oral anticoagulation undergoing percutaneous coronary intervention (PCI) 1
• The trial randomized 573 patients to either:
  • Dual therapy: Warfarin plus clopidogrel 75 mg daily
  • Triple therapy: Warfarin plus clopidogrel 75 mg daily plus aspirin 1
• Patient characteristics included:
  • 27.5% with acute coronary syndrome (ACS)
  • 65% received drug-eluting stents (DES)
  • 69% had atrial fibrillation as indication for anticoagulation
  • 74% underwent PCI via femoral approach 1

Key Findings

• Primary endpoint: The warfarin-clopidogrel arm had significantly less total bleeding (TIMI major plus minor) compared to triple therapy (19.5% vs. 44.9%) 1
• Secondary endpoints:
  • No statistically significant differences in major bleeding events 1
  • No significant differences in ischemic events (MI, stent thrombosis, stroke, target vessel revascularization) 1
  • All-cause mortality was lower in the dual therapy group (2.5% vs. 6.4%, p=0.027) at 1 year 1

Limitations of the WOEST Trial

• Small sample size with limited statistical power, especially for ischemic outcomes 1
• Open-label design introducing potential bias 1
• Low use of proton pump inhibitors for gastric protection 1
• Predominance of femoral access (74%) which carries higher bleeding risk than radial 1
• High prevalence of stable coronary artery disease (70%) rather than ACS 1
• Relatively simple coronary lesions treated 1
• One-year triple therapy duration for DES patients, which is longer than current recommendations 1
• Target INR of 2.0-3.0 without knowledge of actual levels achieved or time in therapeutic range 1

Clinical Impact and Subsequent Developments

• WOEST was the first randomized trial to challenge the standard practice of triple therapy in anticoagulated patients undergoing PCI 1
• The findings influenced subsequent guidelines suggesting that dual therapy with an oral anticoagulant plus clopidogrel may be considered as an alternative to triple therapy in selected patients 1
• Later trials such as PIONEER AF-PCI and RE-DUAL PCI have further explored alternative antithrombotic strategies, including NOACs instead of warfarin 1
• Current guidelines now recommend shorter durations of triple therapy followed by dual therapy with an oral anticoagulant plus a P2Y12 inhibitor (preferably clopidogrel) 1

Practical Application

• Dual therapy with warfarin and clopidogrel could be considered in patients with:
  • Higher bleeding risk
  • Lower ischemic/thrombotic risk 1
• The results may be less applicable to patients with:
  • Acute coronary syndromes
  • Complex coronary anatomy
  • High risk of stent thrombosis 1

Ongoing Research

• The WOEST-3 trial is currently investigating a strategy of temporarily omitting oral anticoagulation and using dual antiplatelet therapy for 30 days after PCI in AF patients 2
• Other trials like AUGUSTUS and ENTRUST-AF-PCI have provided additional evidence on treatment approaches to balance bleeding and thrombotic risks in this complex patient population 1