Why is this study important?

The preferred antiplatelet monotherapy for patients with stable coronary artery disease after PCI remains a clinical dilemma. Multiple trials have recently been presented and published regarding clopidogrel versus aspirin for monotherapy after one year of dual antiplatelet therapy. However, an even longer-term evaluation has not yet been performed.​

The “Harmonizing Optimal Strategy for Treatment of Coronary Artery Disease - Extended Antiplatelet Monotherapy” (HOST-EXAM) trial enrolled 5,530 patients who were event-free after dual antiplatelet therapy for 12 to 18 months after PCI. They were then randomized to receive either clopidogrel monotherapy or aspirin monotherapy.​

What question was this clinical trial supposed to answer?

In actual clinical practice, cardiologists follow patients indefinitely after PCI on a regular basis. This trial was designed to answer the question of the clinical benefit versus risk of antiplatelet monotherapy with either clopidogrel or aspirin for chronic maintenance therapy for a follow-up of 10 years.​

The primary endpoint was a composite of all-cause death, non-fatal myocardial infarction, stroke, and hospital admission due to acute coronary syndrome. The bleeding complications were defined as Bleeding Academic Research Consortium (BARC) >3 bleeding. The primary evaluation included the intention-to-treat population. Multiple subgroups were also evaluated. 

What did the study show?

The results were previously presented after two years of follow-up and after 5.8 years of follow-up. This presentation revealed the evaluation of the clinical data at a mean of 10.5 years after PCI.

The clinical results reveal that the clopidogrel group versus the aspirin group was associated with a lower incidence of the primary composite endpoint that was statistically significant. ​

In addition, the clopidogrel group also had a lower rate of bleeding endpoints, which was also clinically significant. Subgroup analysis revealed that the clopidogrel group had a lower rate of thrombotic endpoints. All-cause mortality did not differ significantly between the two groups. ​

Therefore, the results suggest that after successful PCI for stable coronary artery disease and a period of dual antiplatelet therapy, clopidogrel monotherapy was clinically superior and had less side effects than aspirin monotherapy. These data will affect current clinical practice.