Study of the safety and efficacy of postoperative antiplatelet therapy after percutaneous coronary intervention: a single-center retrospective cohort study
Authors: Dai Lujia 
Published: June 2023

Abstract
Aim: In view of the ethnic characteristics, the safety and efficacy of ticagrelor and clopidogrel in East Asian patients who need recieve dual antiplatelet therapy (DAPT) is a topic which still worth discussing. For the safety and efficacy of aspirin and P2Y12 receptor inhibitors in long-term single antiplatelet therapy (SAPT) after DAPT, there is no conclusion yet. Our study aimed to analyse the safety and efficacy of ticagrelor and clopidogrel in patients who received DAPT after percutaneous coronary intervention (PCI) as well as to analyse the safety and efficacy of aspirin and P2Y12 receptor inhibitors in patients who received DAPT for 1 year after PCI retrospectively.
Methods: A total of 1006 patients undergoing PCI who received DAPT were retrospectively analysed in this study, which were divided into clopidogrel group (n=321) and ticagrelor group (n=685) according to different antiplatelet regiments. The incidence of major cardiovascular and cerebrovascular events (MACCEs) and bleeding events in two groups were compared and analysed during 12 months follow-up. For above-mentioned patients who completed 12 months DAPT then converted to long-term SAPT which add up to 814, these patients were divided into aspirin group (n=706) and non-aspirin group (n=108) according to different SAPT regimen. The incidence of MACCEs and bleeding events in two groups were compared and analysed during 36 months follow-up.
Results: In patients who received DAPT after PCI, there was no significant difference in the incidence of MACCEs between ticagrelor group and clopidogrel group (4.2% vs. 6.2%, HR=1.47, 95% CI: 0.85-2.57; p＞0.05). The incidence of bleeding events in the ticagrelor group was significantly higher than the clopidogrel group (10.8% vs. 6.2%, HR=0.58, 95% CI: 0.36-0.93, p=0.020). Kaplan-Meier survival curve analysis showed that there was no significant difference in the incidence of MACCEs between ticagrelor group and clopidogrel group (4.2% vs. 6.2%, Plog-rank>0.05). The incidence of bleeding events in the ticagrelor group was higher than clopidogrel group (10.8% vs. 6.2%, Plog-rank=0.021). In patients who after PCI and received DAPT for 1 year then converted to SAPT, the incidence of MACCEs in the aspirin group was significantly higher than the non-aspirin group (7.2% vs. 1.9%, HR=0.26, 95% CI: 0.06-1.04; p=0.035). There was no significant difference in the incidence of bleeding events between aspirin group and non-aspirin group (2.7% vs. 3.7%, HR=1.38, 95% CI: 0.48-3.97; p＞0.05). Kaplan-Meier survival curve analysis showed that the incidence of MACCEs in aspirin group was higher than non-aspirin group (7.2% vs. 1.9%, Plog-rank=0.037). There was no significant difference in the incidence of bleeding events between aspirin group and non-aspirin group (2.7% vs. 3.7%, Plog-rank>0.05).
Conclusions: In patients after PCI and accepted DAPT, ticagrelor had a similar MACCEs event incidence than clopidogrel, but had a higher risk of bleeding. P2Y12 receptor inhibitors do not increase bleeding risk versus aspirin and significantly reduce the occurence of MACCEs in patients who received long-term SAPT after DAPT.