P2Y12 inhibitor pretreatment in patients with nonST-segment elevation acute coronary syndrome: A meta-analysis

The 2020 European Society of Cardiology guidelines do not recommend pretreatment for nonST-segment elevation myocardial infarction (NSTEMI) patients with unclear coronary anatomy, which is inconsistent with our routine preoperative approach to loading P2Y12 receptor inhibitors (e.g., preoperative loading of 300 mg of clopidogrel).The purpose of our study was to compare the safety and effectiveness of P2Y12 inhibitors administered before coronary angiography or at least before percutaneous coronary intervention (PCI) with during or after PCI.Cochrane, PubMed, and Embase databases were searched. The primary effect endpoint and safety endpoint were any-cause death and major bleeding, respectively. Major adverse cardiovascular events, myocardial infarction and revascularization were also analyzed.Our search identified 9 trials. P2Y12 inhibitor pretreatment was associated with lower death from any cause (OR 0.62, 95% CI 0.53-0.72, P0.00001) without increasing the risk of bleeding (OR 1.02, 95% CI 0.80-1.30, P = 0.89). However, prasugrel or ticagrelor pretreatment was not associated with a lower risk of mortality (OR 0.70, 95% CI 0.31-1.59, P = 0.40) and increased the risk of bleeding (OR 1.67, 95% CI 1.10-2.54, P = 0.02).In summary, clopidogrel pretreatment was associated with significantly lower mortality, major adverse cardiovascular events, myocardial infarction and revascularization with no increase in major bleeding. However, these advantages were not observed with prasugrel or ticagrelor pretreatment.