Ticagrelor as Compared to Clopidogrel Following Percutaneous Coronary Intervention for Acute Coronary Syndrome

Dual antiplatelet therapy with acetylsalicylic acid and a P2Y12 inhibitor has become a mainstay of therapy after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Although higher-potency P2Y12 inhibitors are preferred over clopidogrel in major society guidelines, recent evidence has questioned the extent of the benefit. It is important to evaluate the relative efficacy and safety of P2Y12 inhibitors in a real-world setting. This is a retrospective cohort study of all patients who underwent PCI for ACS in a Canadian province from January 1, 2015 to March 31, 2020. Baseline characteristics, including co-morbidities, medications, and bleeding risk, were obtained. Propensity matching was used to compare patients who received ticagrelor versus clopidogrel. The primary outcome was occurrence of major adverse cardiovascular events (MACEs) at 12 months, defined as death, nonfatal myocardial infarction, or unplanned revascularization. Secondary outcomes included all-cause mortality, major bleeding, stroke, and all-cause hospitalization. A total of 6,665 patients were included; 2,108 received clopidogrel and 4,214 received ticagrelor. Patients who received clopidogrel were older, had more co-morbidities, including cardiovascular risk factors, and had a higher bleeding risk. In 1.925 propensity score-matched pairs, ticagrelor was associated with a significantly lower risk of MACE (hazard ratio 0.79, 0.67 to 0.93, p <0.01) and hospitalization (hazard ratio 0.85, 0.77 to 0.95, p <0.01). No difference was observed in the risk of major bleeding. A statistically nonsignificant trend toward reduced risk of all-cause mortality was noted. In conclusion, in a real-world high-risk cohort, ticagrelor was associated with decreased risk of MACE and all-cause hospitalization compared with clopidogrel after PCI for ACS.