Clopidogrel or prasugrel vs. aspirin monotherapy for long-term secondary prevention after percutaneous coronary intervention for acute coronary syndrome
Y Iwanaga, K Kanaoka, K Takegawa, H Matsuura, S Chishaki-Kawabata, Y MiyamotoAbstract
Background
Optimal long-term antiplatelet monotherapy in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI) remains a subject of ongoing debate. In particular, it remains unclear whether different P2Y12 inhibitors provide comparable clinical benefits when used as long-term monotherapy. We investigated the efficacy and safety of antiplatelet monotherapy following dual antiplatelet therapy (DAPT) in patients with ACS, using a Japanese nationwide administrative claims database.
Methods
This retrospective study included patients with ACS who underwent PCI with drug-eluting stent implantation and received antiplatelet monotherapy after a minimum of 6 months of DAPT between April 2014 and March 2020. Net adverse clinical events (NACE), a composite of thromboembolism, major bleeding, and all-cause death, were compared between patients receiving clopidogrel 75 mg or prasugrel 3.75 mg and those receiving aspirin 75–100 mg using an inverse probability of treatment weighting (IPTW) analysis.
Results
Of the 109,077 patients included, 50,189 (46.0%) were aged 70 years and older, and 25,123 (23.0%) were female. Of these, 19,479 (17.9%), 9,067 (8.3%), and 80,531 (73.8%) patients received clopidogrel, prasugrel, and aspirin monotherapy, respectively. With a median (IQR) follow-up of 1,542 (1,071–2,092) days after the index PCI, NACE occurred in 1,423 patients (3.53 per 100 person-years) in the clopidogrel group, 408 patients (2.68 per 100 person-years) in the prasugrel group, and 5,490 patients (3.05 per 100 person-years) in the aspirin group after the 18-month landmark period. The IPTW-adjusted hazard ratio (HR) of NACE was 1.03 (95% confidence interval [CI]: 0.96–1.10, p=0.40) in the clopidogrel group and 1.01 (95% CI: 0.89–1.14, p=0.92) in the prasugrel group compared with the aspirin group. The prasugrel group showed a lower hazard ratio of thromboembolism (HR: 0.74 [95% CI: 0.60–0.92], p=0.008) and no differences in major bleeding event (HR: 1.13 [95% CI: 0.87–1.48]).
Conclusions
In patients after PCI for ACS, long-term monotherapy with clopidogrel or prasugrel showed no significant difference in NACE compared with aspirin. Prasugrel use was associated with a lower risk of thromboembolic events without an increased risk of severe bleeding.