Effect of aspirin treatment duration on clinical outcomes in acute coronary syndrome patients with early aspirin discontinuation and received P2Y12 inhibitor monotherapy

Abstract

Abstract Background/Introduction Recent clinical trials showed that short aspirin duration (1 or 3 months) in dual antiplatelet therapy (DAPT) followed by P2Y12 inhibitor monotherapy reduced the risk of bleeding and did not increase the ischemic risk compared to 12-month DAPT in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). However, it is unclear about the optimal duration of aspirin in P2Y12 inhibitor monotherapy. Purpose The purpose of this study was to evaluate the influence of aspirin treatment duration on clinical outcomes in a cohort of ACS patients intolerant to aspirin with early aspirin interruption and received P2Y12 inhibitor monotherapy. Methods From January 1, 2014 to December 31, 2018, we included 498 ACS patients with aspirin stopped for various reasons before 6 months after PCI and received P2Y12 inhibitor monotherapy. The efficacy and safety between the groups of early (≤1 month) and late discontinuation (>1 month) of aspirin were compared in 12-month follow up after PCI. To adjust for potential confounding due to baseline imbalances in study covariates while preserving sample size, we used the inverse probability of treatment weights (IPTW) method based on the propensity score. Results The mean duration of aspirin treatment was 7.52±8.10 days in the early and 98.05±56.70 days in the late discontinuation group (p<0.001). The primary endpoint was the composite of all-cause mortality, recurrent ACS or unplanned revascularization, and stroke within 12 months. The safety endpoint was major bleeding, defined as BARC 3 or 5 bleeding. In the multivariate Cox proportional-hazards models, there was no difference in the primary endpoint (adjusted hazard ratio 1.19, 95% confidence interval 0.85–1.68) between the groups. The safety outcome of BARC 3 or 5 bleeding was also similar (Figure 1). In conclusion, patients with early discontinuation of aspirin had similar clinical outcomes to those with late discontinuation. Conclusion The risk of major adverse cardiac events was similar between those with aspirin treatment >1 month versus ≤1 month in ACS patients undergoing PCI who cannot tolerate aspirin and received P2Y12 inhibitor monotherapy. Under P2Y12 inhibitor therapy, early discontinuation of aspirin ≤1 month after PCI maybe feasible and safe. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): National Cheng-Kung university hospital Figure 1