Prasugrel monotherapy versus standard DAPT in STEMI patients with OCT-guided or angio-guided complete revascularisation: design and rationale of the randomised, multifactorial COMPARE STEMI ONE trial.

Monotherapy with a potent P2Y receptor antagonist after 1 month of dual antiplatelet therapy (DAPT) may reduce bleeding in the absence of increased ischaemic events compared to 12-month DAPT in patients with acute coronary syndrome undergoing percutaneous coronary intervention (PCI). PCI guidance with optical coherence tomography (OCT) may enhance stent expansion. COMPARE STEMI ONE is an international, multicentre, open-label, randomised controlled trial. In 1,656 ST-segment elevation myocardial infarction (STEMI) patients, prasugrel monotherapy after 1 month of DAPT, as compared to standard 12-month prasugrel-based DAPT, will be tested for non-inferiority for the primary composite endpoint of net adverse clinical events - defined as all-cause death, myocardial infarction, stroke, or Bleeding Academic Research Consortium Type 3 or 5 bleeding events - at 11 months after randomisation. Furthermore, an ancillary substudy will test the superiority of OCT-guided versus angiography-guided staged complete revascularisation in achieving a larger minimal stent area (MSA) in non-culprit lesions during staged procedures. COMPARE STEMI ONE is the first randomised controlled trial assessing an abbreviated 1-month DAPT regimen followed by prasugrel monotherapy in the context of STEMI. The trial will also study the value of OCT-guided PCI in terms of the MSA of non-culprit lesions and may elucidate potential synergies between intravascular imaging-guided PCI and abbreviated DAPT regimens. (ClinicalTrials.gov: NCT05491200).