3293Atherothrombotic risk and outcomes following guided de-escalation of antiplatelet treatment in patients with acute coronary syndrome:a post-hoc analysis of the TROPICAL-ACS trial

Abstract

Abstract Background A de-escalation of P2Y12-inhibitor treatment guided by platelet function testing (PFT) has been identified as a safe and alternative treatment strategy in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). However, no specific data are available on the efficacy of such strategy in patients with high atherothrombotic risk (ATR). Purpose To investigate the safety and efficacy of guided de-escalation of P2Y12-inhibitor treatment in patients with low- vs. high-ATR. Methods The TROPICAL-ACS trial randomized 2,610 biomarker-positive ACS patients 1:1 to either conventional treatment with prasugrel for 12 months (control group) or to a PFT guided de-escalation treatment strategy (guided de-escalation group). The primary endpoint was defined as the composite of cardiovascular mortality (CVM), myocardial infarction (MI), stroke, and clinically overt bleeding (bleeding ≥ grade 2 according to the BARC criteria). The ischemic endpoint was defined as the composite of CVM, MI or stroke. We used semi-parametric Cox regression analysis and interaction testing to assess the effect of low- vs. high-ATR on the primary and ischemic endpoints. High-ATR was defined as one of the following: (i) age ≥65 years or (ii) age <65 and either history of peripheral artery disease or at least two of the following risk-factors: diabetes mellitus, current smoking or renal dysfunction. Results Patients with high- (n=990) versus low-ATR (n=1,620) exhibited a higher risk for the primary endpoint (11.0% vs. 6.7%; HR 1.67; 95% CI 1.28–2.18; p<0.001). Guided de-escalation was non-inferior to conventional treatment for the primary endpoint in both patients with high- (10.5% vs. 11.5%; pnon-inferiority = 0.029; Figure 1A) and low-ATR (5.6% vs. 7.7%; pnon-inferiority=0.001; Figure 1B). Moreover, there was no significant interaction in the prognostic value of guided de-escalation between high- and low-ATR groups for both the primary (HR 0.90 [0.61–1.32]; p=0.586 in patients with high-ART vs. 0.71 [0.48–1.04; p=0.082 in patients with low-ATR; pinteraction= 0.394) and combined ischemic endpoints (HR 0.83 [0.44–1.56]; p=0.567 in patients with high-ATR vs. 0.68 [0.35–1.34]; p=0.262 in patients with low-ATR; pinteraction =0.666). Kaplan-Meier curves Conclusion A guided DAPT de-escalation strategy appears to be safe and effective in ACS patients regardless of the atherothrombotic risk. Further studies are needed for refining antiplatelet treatment strategies in ACS patients with varying levels of atherothrombotic risk. Acknowledgement/Funding Klinikum der Universität München, Roche Diagnostics, Eli Lilly, and Daiichi Sankyo.