The first 3 months after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS) is a high-risk period for adverse events, including ischemic and bleeding events, which decrease greatly with time. It is worth investigating whether the use of potent P2Y12 inhibitors is necessary after the early stage. The purpose of this study was to investigate the differences in clinical outcomes between clopidogrel and ticagrelor in stable patients without ischemic or major bleeding events during the first 3 months after PCI.

Data for this study were obtained from the PHARM-ACS registry (NCT04184583). Patients who were free from ischemic and major bleeding events in the first 3 months after PCI were enrolled. Inverse probability of treatment weighting (IPTW) and Cox proportional hazards model were applied to compare the differences in clinical outcomes between the 2 groups. Major adverse cardiovascular and cerebrovascular events (MACCE) were considered the primary end point, and major bleeding was considered the secondary end point.

A total of 6662 patients were included in this study. Of these, 3465 were treated with clopidogrel plus aspirin (clopidogrel group) and 3197 with ticagrelor plus aspirin (ticagrelor group). There were no significant differences in MACCE after IPTW adjustment for baseline variables (IPTW-adjusted HR, 1.06; 95% CI, 0.90–1.25) or major bleeding events (IPTW-adjusted HR, 0.97; 95% CI, 0.67–1.41) between the 2 groups. However, the incidence of minor bleeding in the clopidogrel group was significantly lower than that in the ticagrelor group (IPTW-adjusted HR, 0.65; 95% CI, 0.59–0.71).

In patients with ACS who were free from ischemic or major bleeding events during the first 3 months after PCI, the subsequent clopidogrel treatment might reduce minor bleeding events without increasing the risk of MACCE compared with ticagrelor. However, the results still need to be confirmed by large randomized controlled studies in the future.