Intensive oral antiplatelet therapy for reduction of ischaemic events including stent thrombosis in patients with acute coronary syndromes treated with percutaneous coronary intervention and stenting in the TRITON-TIMI 38 trial: a subanalysis of a randomised trial

Background Intracoronary stenting can improve procedural success and reduce restenosis compared with balloon angioplasty in patients with acute coronary syndromes, but can also increase the rate of thrombotic complications including stent thrombosis. The TRITON-TIMI 38 trial has shown that prasugrel-a novel, potent thienopyridine-can reduce ischaemic events compared with standard clopidogrel therapy. We assessed the rate, outcomes, and prevention of ischaemic events in patients treated with prasugrel or clopidogrel with stents in the TRITON-TIMI 38 study. Methods patients with moderate-risk to high-risk coronary syndromes ware included in our analysis if they had received at least one coronary stent at the time of the index procedure following randomisation in TRITON-TIMI 38, and were further subdivided by type of stent received. Patients were randomly assigned in a 1 to 1 fashion to receive a loading dose of study drug (prasugrel 60 mg or clopidogrel 300 mg) as soon as possible after randomisation, followed by daily maintenance therapy (prasugrel 10 mg or clopidogrel 75 mg). All patients were to receive aspirin therapy. Treatment was to be continued for a minimum of 6 months and a maximum of 15 months. Randomisation was not stratified by stents used or stent type. The primary endpoint was the composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke. Stent thrombosis was assessed using Academic Research Consortium definitions, and analysis was by intention to treat. TRITON-TIMI 38 is registered with ClinicalTrials.gov, number NCT 00097591. Findings 12 844 patients received at least one coronary stent; 5743 received only drug-eluting stents, and 6461 received only bare-metal stents. Prasugrel compared with clopidogrel reduced the primary endpoint (9.7 vs 11.9%, HR 0.81, p=0.0001) in the stented cohort, in patients with only drug-eluting stents (9.0 vs 11.1%, HR 0.82, p=0.019), and in pateints with only bare-metal stents (10.0 vs 12.2%, HR 0.80, p=0.003). Stent thrombosis was associated with death or myocardial infarction in 89% (186/210) of patients. Stent thrombosis was reduced with prasugrel overall (1.13 vs 2.35%, HR 0.48, p<0.0001), in patients with drug-eluting stents only (0.84 vs 2.31%, HR 0.36, p<0.0001), and in those with bare-metal stents only (1.27 vs 2.41%, HR 0.52, p=0.0009). Interpretation Intensive antiplatelet therapy with prasugrel resulted in fewer ischaemic outcomes including stent thrombosis than with standard clopidogrel. These findings were statistically robust irrespective of stent type, and the data affirm the importance of intensive platelet inhibition in patients with intracoronary stents. Funding TRITON-TIMI 38 was supported by research grants from Daiichi Sankyo and Eli Lilly.