Background: Patients undergoing complex
percutaneous coronary intervention (PCI) have an increased risk of cardiovascular events. Whether potent antiplatelet
therapy after complex PCI improves outcomes in patients with stable
coronary artery disease (SCAD) remains unclear. Objectives: To assess the efficacy and safety of
ticagrelor vs.
clopidogrel in patients with SCAD undergoing complex PCI. Methods: Patients with a diagnosis of SCAD and undergoing PCI during January 2016 to December 2018 were selected from an institutional registry. The primary efficacy endpoint was
major adverse cardiac events (
MACE) within 12 months after PCI. The primary safety endpoint was major
bleeding. Results: Among 15,459 patients with SCAD included in this analysis, complex PCI was performed in 6,335 (41.0%) patients. Of patients undergoing complex PCI, 1,123 patients (17.7%) were treated with
ticagrelor. The primary efficacy outcome after complex PCI occurred in 8.6% of patients in the
ticagrelor group and 11.2% in the
clopidogrel group. Compared with
clopidogrel,
ticagrelor decreased the risk of
MACE in patients undergoing complex PCI [adjusted hazard ratio (HR): 0.764; 95% confidence interval (CI): 0.615 to 0.949; p = 0.015], but not in non-complex PCI (p for interaction = 0.001). There was no significant difference in incidence of major
bleeding between patients treated with
ticagrelor and
clopidogrel (p = 0.221), while
ticagrelor was associated with an increased risk of minor
bleeding (adjusted HR: 3.099; 95% CI: 2.049 to 4.687; p < 0.001). Conclusion: In patients with SCAD and undergoing complex PCI,
ticagrelor could substantially reduce the risk of adverse cardiovascular outcomes without increasing the risk of major
bleeding compared with
clopidogrel.