Association between P2Y12 inhibitor reloading and in-hospital outcomes for patients with non-ST-segment elevation acute coronary syndrome already on chronic P2Y12 receptor inhibitors therapy in China: findings from the CCC-ACS (improving care for cardiovascular disease in China-acute coronary syndrome) project

Background The association between P2Y12 receptor inhibitors reloading and in-hospital outcomes in non-ST-segment elevation acute coronary syndrome (NSTEACS) patients who were on chronic P2Y12 receptor inhibitors therapy remained underdetermined.Methods The Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome (CCC-ACS project) is a national registry active from November 2014 to December 2019. 4790 NSTEACS patients on chronic P2Y12 receptor inhibitors therapy were included. Cox proportional hazard models, Kaplan-Meier curves, and subgroup analyses were conducted.Results The NSTEACS patients who received reloading of P2Y12 receptor inhibitors were younger and had fewer comorbid conditions. The reloading group had a lower risk of major adverse cardiac events (MACE) (0.51% vs. 1.43%, P = 0.007), and all-cause death (0.36% vs. 0.99%, P = 0.028), the risks of myocardial infarction and major bleeding were not significantly different between patients with and without reloading. In survival analysis, a lower cumulative risk of MACE could be identified (Log-rank test, P = 0.007) in reloading group. In the unadjusted Cox model, reloading P2Y12 receptor inhibitors was associated with a decreased risk of MACE [HR, 0.35; 95% CI 0.16-0.78; (P = 0.010)] and all-cause death [HR, 0.37; 95% CI 0.14-0.94; (P = 0.036)]. Reloading of P2Y12 receptor inhibitors was associated with a decreased risk of MACE in most of the subgroups.Conclusions In NSTEACS patients already taking P2Y12 receptor inhibitors, we observed a decreased risk of in-hospital MACEs and all-cause mortality and did not observe an increased risk of major bleeding, with reloading. The differential profile in the two groups might influence this association and further studies are warranted.