Association of P2Y12 inhibitor pretreatment strategy with short and long term ischemic and bleeding outcomes in NSTE-ACS patients
Authors: Keskin K , Eren S , Korkmaz B , Kolak Giousouf Chousein Z , Mollaalioglu F , Coskun C , Akyuz S , Karatas M B , Unal Dayi S , Calik A N 
Published: October 2024

Abstract

Background and Aims
Oral P2Y12 inhibitors form the basis of both short and long term antiplatelet therapy in NSTE-ACS patients. While reducing thrombogenic activity and ischemic risk is the basis of routine P2Y12 inhibitor pretreatment in NSTE-ACS patients, timing of treatment became controversial as a result of studies showing routine P2Y12 inhibitor pretreatment is associated with an increased risk of bleeding. Even though routine pretreatment is no longer recommended in the ESC guidelines, the inadequacies in RCTs combining all treatment modalities have been noted. Our study aims to determine the relationship between P2Y12 inhibitor pretreatment strategy and short and long-term ischemic and bleeding events.

Methods
The study was designed as a single-center, prospective and observational study. 2602 patients, aged between 18 and 85, diagnosed with NSTE-ACS in accordance with ESC guidelines were included in the study. 2189 patients were administered with P2Y12 inhibitor pretreatment while 413 patients weren't. Demographic data, CVD risk factors, ECG, echocardiography and laboratory findings at the time of admission, interventional procedural details, type of antiplatelet and anticoagulant treatment and application time were recorded. Patients were divided into two groups as pretreatment and no-pretreatment according to the time of administration of P2Y12 inhibitor loading dose. In the no-pretreatment group choice of P2Y12 inhibitor was left to operator in the cath lab before proceeding to PCI. Post-procedural in-hospital and long term follow up (1 year) were obtained through hospital and national registry systems and patient survey.

Results
In the no-pretreatment group 91.3% of patients underwent coronary angiography and PCI was performed in 51.8%. In patients proceeding to PCI, 58.5% were given clopidogrel and 41.5% were given a potent P2Y12 inhibitor. In the pretreatment group, clopidogrel was the drug of choice in 93.8% of patients. In the pretreatment group, the primary composite endpoint (MACE and bleeding events) were more common during in-hospital follow-up and this difference was due to a significant increase in both BARC class I & II and class III, IV & V bleedings (Table 1). In the long-term follow up, statistically significant difference was only seen in BARC class I & II bleedings in the pretreatment group. There were no difference in MACE rates in neither in-hospital or long-term follow up (Table 2). Also in multivariate regression analysis, pretreatment with a P2Y12 inhibitor was found to be an independent predictor of short term primary composite endpoints and long-term all-cause mortality.

Conclusion
The results of our study investigating the effects of the P2Y12 inhibitor pretreatment strategy on ischemic and bleeding endpoints in NSTE-ACS patients showed that the pretreatment strategy did not lead to an improvement in MACE rates in in-hospital and long-term follow-up but caused on overall increase in bleeding events.Kaplan-Meier Survival Analysis