Temporal trends in the use of P2Y12 inhibitors over 15 years and their impact on in-hospital bleeding and mortality among patients with acute myocardial infarction in Switzerland

Background Current guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor – prasugrel or ticagrelor preferred over clopidogrel – in virtually all patients with acute myocardial infarction (AMI). While clopidogrel (1998) was the first drug introduced, prasugrel (2009) and ticagrelor (2011) subsequently emerged as more potent alternatives. Methods For this study, we interrogated the AMIS Plus database of ST-elevation myocardial infarction (STEMI) and non-STEMI patients admitted to Swiss hospital between 2009 and 2024 with available data on immediate treatment (within 24 hours after hospital admission) with P2Y12 inhibitors. We plotted yearly percentual application of the different P2Y12 inhibitors together with bleeding and in-hospital mortality prevalences over time. Then, we used multinomial propensity scores to balance baseline characteristics across the P2Y12 inhibitors, assessed covariate balance, and estimated weighted odds ratios for bleeding and in-hospital mortality. For the latter analysis, we excluded patients on oral anticoagulation as well as patients with P2Y12 inhibitor monotherapy. Results Among the 41,244 AMI patients enrolled in AMIS Plus during the study period, 29.3% were on clopidogrel, 21.1% on prasugrel, 35.9% on ticagrelor, and 34,736 (84.2%) patients were on DAPT. The median ages of patients on clopidogrel, prasugrel and ticagrelor were 66.8 [interquartile range (IQR) 56.4, 76.9] years, 59.5 (IQR 52.2, 67.0) years, and 65.9 (IQR 56.5, 75.6) years, respectively. Out of the patients who received prasugrel, 83.5% were male, compared with 73.8% in the clopidogrel group and 75.4% in the ticagrelor group. Overall, crude bleeding and in-hospital mortality rates were 3.8% and 4.8%, respectively. Application frequencies of the three different P2Y12 inhibitors across the study period are displayed in Figure A. Pairwise comparisons of the three P2Y12 inhibitors in terms of bleeding complications showed no significant differences between the drugs (Figure B). In terms of in-hospital mortality, clopidogrel showed the highest and prasugrel the lowest odds (Figure B). Conclusion Over the study period, we observed no difference between the drugs for bleeding complications. Prasugrel use was associated with the lowest odds of in-hospital mortality, while clopidogrel had the highest odds.