Aspirin vs. Clopidogrel for Long-Term Maintenance After PCI

Quick Takes

  • Clopidogrel showed lower rates of the primary composite endpoint as well as the thrombotic composite endpoint and any bleeding at 24 months after coronary stenting regardless of the presence of diabetes.
  • Furthermore, clopidogrel was especially beneficial in patients with diabetes in terms of 24-month MACE, a composite of all-cause death, MI, and stroke.
  • If validated in additional dedicated prospective studies, these results may inform decision making for long-term therapy following PCI especially among those with diabetes.

Study Questions:

What are the cardiovascular outcomes with clopidogrel versus aspirin for long-term maintenance after percutaneous coronary intervention (PCI) in patients with and without diabetes?

Methods:

The investigators conducted a post hoc analysis of the HOST-EXAM (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis–Extended Antiplatelet Monotherapy) randomized clinical trial, an investigator-initiated, prospective, randomized, open-label, multicenter trial performed at 37 centers in Korea. Patients who received dual antiplatelet therapy (DAPT) without clinical events for 6-18 months after PCI with drug-eluting stents were enrolled from March 2014 to May 2018 with follow-up at 6, 12, 18, and 24 months. All 5,438 patients in the original trial were included in this analysis, which was conducted from June to October 2021. Enrolled patients were randomized 1:1 to clopidogrel or aspirin monotherapy. Subgroup analyses were performed by the presence of diabetes. The main outcome was the primary composite endpoint of all-cause death, nonfatal myocardial infarction (MI), stroke, readmission due to acute coronary syndrome, and major bleeding (Bleeding Academic Research Consortium type 3 or 5) at 24-month follow-up. Cumulative incidences of the primary and secondary endpoints were compared between clopidogrel and aspirin monotherapy using Kaplan-Meier censoring estimates and the log-rank test. Hazard ratios (HRs) with 95% confidence intervals (CIs) of clopidogrel versus aspirin monotherapy were calculated using Cox proportional hazard models with interaction testing according to the presence of diabetes.

Results:

Of 5,438 patients (mean [SD] age, 63.5 [10.7] years; 1,384 [25.5%] female), 1,860 (34.2%) had diabetes (925 in the clopidogrel arm and 935 in the aspirin arm), and 5,338 (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%; HR, 0.69; 95% CI, 0.49-0.96; p = 0.03; absolute risk difference [ARD], 2.7%; number needed to treat [NNT], 37) and without diabetes (5.3% vs. 7.0%; HR, 0.76; 95% CI, 0.58-1.00; p = 0.046; ARD, 1.6%; NNT, 63; p for interaction = 0.65). 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; 95% CI, 0.45-1.04 for patients with diabetes vs. HR, 0.68; 95% CI, 0.49-0.93 for those without; p for interaction = 0.99) and any bleeding with Bleeding Academic Research Consortium 2, 3, or 5 (HR, 0.65; 95% CI, 0.39-1.09 for patients with diabetes vs. HR, 0.74; 95% CI, 0.48-1.13 for those without; p for interaction = 0.71).

Conclusions:

The authors report that clopidogrel monotherapy was associated with a lower rate of the primary composite endpoint compared to aspirin monotherapy as long-term maintenance therapy after DAPT for coronary stenting in both patients with and without diabetes.

Perspective:

This post hoc analysis of the open-label HOST-EXAM randomized clinical trial reports that clopidogrel showed lower rates of the primary composite endpoint as well as the thrombotic composite endpoint and any bleeding at 24 months after coronary stenting regardless of the presence of diabetes. Furthermore, clopidogrel was especially beneficial in patients with diabetes in terms of 24-month major adverse cardiovascular events (MACE), a composite of all-cause death, MI, and stroke. If validated in additional dedicated prospective studies, these results may inform decision making for long-term therapy following PCI especially among those with diabetes with clopidogrel preferred over aspirin.

Clinical Topics: Acute Coronary Syndromes, Invasive Cardiovascular Angiography and Intervention, Prevention, Interventions and ACS

Keywords: Acute Coronary Syndrome, Aspirin, Clopidogrel, Diabetes Mellitus, Drug-Eluting Stents, Hemorrhage, Myocardial Infarction, Myocardial Ischemia, Patient Readmission, Percutaneous Coronary Intervention, Platelet Aggregation, Secondary Prevention, Stroke, Vascular Diseases


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