PM223 Prevalence of High On-Treatment Platelet Reactivity To Aspirin In Patients With Stable Coronary Artery Disease

Abstract

Introduction: Drug-eluting stents (DES) reduce in stent restenosis by local delivery of antiproliferative drugs embedded onto their metallic backbone. Antiproliferative drugs have also been thought to cause a local inflammatory effect that could lead to stent thrombosis. The risk of stent thrombosis is greatest in the first month following elective DES implantation. Double antiplatelet therapy (DAPT) prescribed prior to DES implantation and recommended for 12 months after. DAPT is associated with an increased risk in bleeding, therefore platelet function testing (PFT) is utilized to assess their efficacy. Everolimus-eluting (EES) are amongst the most common DES used at our centre. Objectives: We aimed to compare elements of DAPT by PFT to assess if there are more adverse clinical events in patients implanted with EES compared with non-EES. Methods: From 474 consecutive patients undergoing elective percutaneous coronary intervention (PCI), 137 patients were implanted with DES having had pretreatment of Aspirin 75mg OD and Clopidogrel 75mg OD for 4 days. PFT was assessed with multiple electrode aggregometry (MEA, Multiplate) within 24 hours of PCI. The primary endpoint was major adverse cardiac events (MACE) and bleeding rates up to 1 month post-PCI. Results: We noted that 80 patients were implanted with EES and 57 patients with nonEES. Both groups were well matched for gender, age and established cardiac risk factors. Mean PFT levels for Aspirin were 212.18 98.48 AU*min and 196.3 90.17 AU*min for EES and non-EES groups, respectively. Mean PFT levels for Clopidogrel were 408.65 188.56 AU*min and 466.67 241.74 AU*min for EES and non-EES groups, respectively. There were 12.7% versus 10.5% Aspirin non-responders, 32.9% versus 45.6% Clopidogrel non-responders, in the EES compared with non-EES groups. There was 1 MACE in the EES group, compared with 2 MACE in the non-EES groups. There were 4 minimal bleed events in the EES group compared with the non-EES group. There was no relationship between MACE and Aspirin MEA levels, and no relationship between MACE and Clopidogrel MEA levels, between both groups. Conclusion: Comparing patients implanted with EES or non-EES, neither Aspirin nor Clopidogrel MEA levels were associated with adverse clinical events following 1 month after elective PCI. Disclosure of Interest: None Declared