IntroductionTicagrelor is an oral, reversible, direct-acting P2Y(12) receptor inhibitor approved for the prevention of cardiovascular events in acute coronary syndrome (ACS). In China, drug intensive monitoring regulations for new drugs require additional safety data post-approval.MethodsYINGLONG, a single-arm, phase-IV, 1-year, non-interventional study, described the safety of ticagrelor 90mg twice daily in Chinese patients (>= 18years) with ACS treated with >= 1 dose of ticagrelor. Primary outcomes were the incidence of adverse events (AEs), in particular, PLATelet inhibition and patient Outcomes (PLATO)-defined bleeding AEs, and other serious AEs during the 1-year follow-up. Key secondary outcomes were the incidence of major cardiovascular events.ResultsPatients (n=1041, median age 61.0years) had started ticagrelor and had post-dose data. Median duration of ticagrelor treatment was 357days; 577 patients (55.4%) completed 1-year ticagrelor treatment; 973 patients (93.5%) completed 1-year follow-up. Overall, 38.7% of patients reported an AE during treatment. Themost common AEs were dyspnea (n=37, 3.6%), petechiae (n=30, 2.9%), and chest discomfort (n=28, 2.7%). Serious AEs, excluding bleeding, were reported in 9.8% of patients during treatment. Incidence of PLATO-defined major bleeding events was 1.1% (n=11). Of the 21 deaths that occurred during the study (8 post-treatment), 1 was a fatal bleed. Major cardiovascular events were reported in 37 patients (3.6%).ConclusionsTicagrelor was well tolerated with a low rate of PLATO-defined major bleeding events in Chinese ACS patients. Safety results were consistent with the known ticagrelor profile.Trial RegistrationClinicalTrials.gov identifier, NCT02430493.FundingAstraZeneca Investment (China) Co., Ltd.