HOST-EXAM Trial Analysis: Clopidogrel vs Aspirin

A post hoc analysis of the HOST-EXAM trial in Korea has suggested using clopidogrel over aspirin monotherapy, irrespective of diabetes presence, in patients who have undergone coronary stenting and completed dual antiplatelet therapy (DAPT).

The study, published in JAMA Cardiology, showed that clopidogrel monotherapy was linked with a lower rate of adverse events compared to aspirin monotherapy as long-term maintenance therapy after dual antiplatelet therapy for coronary stenting among people with and without diabetes.

Background

Selection of the optimal antiplatelet agent in patients who have received PCI (percutaneous coronary intervention) is crucial in those with diabetes due to an elevated risk of ischemic events in these patients. Moreover, there is a lack of studies on the safety and efficacy of clopidogrel vs aspirin for long-term maintenance after PCI in people with diabetes.

To fill this knowledge gap, Tae-Min Rhee, Seoul National University College of Medicine, Seoul, Korea, and colleagues aimed to investigate cardiovascular outcomes with clopidogrel versus aspirin in patients with and without diabetes.

Study Design

The researchers performed a post hoc analysis of the HOST-EXAM randomized clinical trial, a prospective, investigator-initiated, randomized, multicenter, and open-label trial conducted in Korea's 37 centres. They enrolled patients who received DAPT without clinical events for 6 to 18 months after PCI with drug-eluting stents and were followed at 6, 12, 18, and 24 months. All 5438 patients in the original trial were included in the analysis conducted from June to October 2021.

Enrolled patients were randomized in the ratio of 1:1 to clopidogrel or aspirin monotherapy. Subgroup analyses were performed by the presence or absence of diabetes.

Primary Outcome

The study's primary outcome was the composite endpoint of nonfatal myocardial infarction, all-cause death, stroke, major bleeding, and readmissions due to acute coronary syndrome at the follow-up of 24 months.

Findings

• Of 5438 patients (mean age, 63.5 years; 25.5% female), 34.2% had diabetes (925 in the clopidogrel arm and 935 in the aspirin arm), and 98.2% completed follow-up.
• The rate of the primary composite endpoint was significantly lower in the clopidogrel group compared to the aspirin group in patients with diabetes (6.3% vs 9.2%; hazard ratio [HR], 0.69; absolute risk difference [ARD], 2.7%; number needed to treat [NNT], 37) and without diabetes (5.3% vs 7.0%; HR, 0.76; ARD, 1.6%, NNT, 63).
• The presence of diabetes was not associated with a difference in benefit observed with clopidogrel monotherapy over aspirin for the thrombotic composite endpoint (HR, 0.68 for patients with diabetes vs HR, 0.68) and any bleeding with Bleeding Academic Research Consortium 2, 3, or 5 (HR, 0.65 for patients with diabetes vs HR, 0.74).

"Clopidogrel could be considered over aspirin monotherapy irrespective of diabetes in patients who have undergone coronary stenting and completed dual antiplatelet therapy," the researchers concluded.

Reference

Rhee T, Bae J, Park KW, et al. Aspirin vs Clopidogrel for Long-term Maintenance After Coronary Stenting in Patients With Diabetes: A Post Hoc Analysis of the HOST-EXAM Trial. JAMA Cardiol. Published online April 12, 2023. doi:10.1001/jamacardio.2023.0592