Highlights from

ACC 2021

American College of Cardiology Annual Congress 2021

Virtual 15-17 May 2021

Clopidogrel superior to aspirin as monotherapy after DAPT in HOST-EXAM trial

Summary: The HOST-EXAM study showed that monotherapy clopidogrel was superior to monotherapy with aspirin in patients who had experienced an event-free 6-12 months following percutaneous coronary intervention (PCI) using a drug-eluting stent (DES) over a 2-year follow-up period.1,2 Clopidogrel was associated with both fewer thrombotic and bleeding endpoints.

In patients who have experienced an acute myocardial infarction (MI) and undergone PCI, guidelines suggest 6-12 months of dual antiplatelet therapy; typically aspirin plus a P2Y12 inhibitor such as clopidogrel. After the initial 6-12 month period, lifetime monotherapy is recommended, and although guidelines do not specify which type of monotherapy, aspirin is the most widely used. Prof Hyo-Soo Kim (Seoul National University Hospital, South Korea) and colleagues aimed to explore whether an alternative monotherapy could achieve superior clinical outcomes as compared with aspirin. To address this question, the multicentre, open-label HOST-EXAM study (NCT02044250) randomised 5,438 patients who had completed 6-12 months of event-free dual antiplatelet therapy (DAPT) following MI and PCI; 2.710 (49.8%) participants took P2Y12 inhibitor clopidogrel only, and 2,728 (50.2%) took aspirin only. All participants were followed for 24 months. The primary endpoint was a composite of all-cause death, acute coronary syndrome including non-fatal MI, stroke, the need for revascularisation while under antiplatelet therapy, and grade ≥3 bleeding academic research consortium (BARC) bleeds. At 2 years, 152 (5.7%) primary endpoint events had occurred in the clopidogrel group compared with 207 (7.7%) in the aspirin group (HR 0.73; 95% CI 0.59–0.70; P=0.0035). The researchers acknowledged some limitations of this trial. It was open-label, and conducted only in South Korea; therefore, results may not be generalisable. Furthermore, most of the enrolled patients had followed a DAPT regimen for about 1 year; thus, results may not be generalisable to those who have been on DAPT for a shorter period.

  1. Kim H S. Aspirin vs. clopidogrel during chronic maintenance monotherapy after percutaneous coronary intervention: the Host Exam randomized controlled trial. Abstract 407-12, ACC 2021 Scientific Session, 15-17 May 2021
  2. Koo B K, Kang J et al. Aspirin versus clopidogrel for chronic maintenance monotherapy after percutaneous coronary intervention (HOST-EXAM): an investigator-initiated, prospective, randomised, open-label, multicentre trial. Lancet 2021 online 16 May 2021 [full text]

Top image: © Lifemoment

Article image: jacoblund

The content and interpretation of these conference highlights are the views and comments of the speakers/authors.