6128A head-to-head comparison of uniform prasugrel treatment vs. clopidogrel treatment for confirmed responders in acute coronary syndrome patients: results from the randomized TROPICAL-ACS trial

Abstract

Background: A strategy of platelet function testing (PFT)-guided de-escalation of dual antiplatelet treatment (DAPT) with an early switch from prasugrel to clopidogrel was recently identified as an effective alternative treatment strategy in acute coronary syndrome (ACS) patients undergoing percutaneous coronary interven-tion (PCI). With this strategy of drug response monitoring, the majority (>60%) of ACS patients (=clopidogrel responders) could be switched over to clopidogrel treatment as early as one week after hospital discharge. However, the out-comes of prasugrel-treated patients vs. confirmed clopidogrel responders warrant a dedicated assessment. Thus, the purpose of this post-hoc analysis from the TROPICAL-ACS trial was to compare the outcomes of prasugrel-treated patients vs. clopidogrel-treated patients with a confirmed responder status. Methods: The TROPICAL-ACS trial randomized 1306 biomarker-positive ACS patients to standard treatment with prasugrel for 12 months (control group) vs. a PFT-guided DAPT de-escalation group (n=1304 patients), among which PFT identified 755 patients as clopidogrel responders. Here, we report on the 1-year outcomes of these two subsets of patients. Results: The primary endpoint occurred in 55 patients in clopidogrel responders and in 118 control group patients (7.3% vs. 9.0%; HR: 0.79, 95% CI: 0.57-1.08 p=0.14, Figure A). Despite early de-escalation with a switch to clopidogrel, there was no increase in the combined risk of cardiovascular death, myocardial infarction or stroke in clopidogrel responders vs. control group patients (2.4% vs. 3.2%, respectively; p for superiority=0.25, p for non-inferiority=0.02, Figure B). The in-cidence of BARC>2 bleedings (key secondary endpoint) was 4.9% in clopidogrel responders vs. 6.1% in control group patients (HR: 0.80, 95% CI: 0.54-1.17; p=0.25). [Figure Presented] Conclusions: A switch over to clopidogrel as early as one week after hospital discharge and continued clopidogrel treatment for up to one year after PCI for ACS in patients with sufficient drug response appears to be equally safe and effective when compared to uniform treatment with the potent ADP receptor inhibitor prasugrel. Funding Acknowledgements: Klinikum der Universität München.