Objectives: The present trial aims at examining whether antiplatelet regimen modification, guided by assessment of the on-treatment platelet reactivity, might result with clinical benefit in moderate to high-risk patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).

Background: High platelet reactivity has been associated with an increased rate of ischemic events after PCI. Recent large trials did not show a clinical benefit of platelet reactivity-guided therapy modification in acute coronary syndrome patients treated by PCI.

Methods: PLATFORM is an investigator-initiated, prospective, randomized, parallel-group, controlled clinical trial. Approximately 632 STEMI patients with intermediate to high-risk (RISK-PCI score >3) clinical features undergoing PPCI will be randomly allocated to treatment modification or standard therapy. Low responders to aspirin will receive 200 mg aspirin for 30 days. Low responders to clopidogrel will receive 180 mg ticagrelor for 1 year. The primary end-point is the time to the first composite major adverse cardiovascular events (MACE) including death, nonfatal infarction, stroke, or immediate target vessel revascularization. Key safety end-point is the rate of TIMI major bleeding unrelated to coronary artery bypass graft surgery. Our secondary end-points are individual components of MACE, definite stent thrombosis, total bleeding, and the need for blood transfusions. Patients will be followed-up at 30 days and at 1 year after PPCI.

Conclusion: PLATFORM will determine whether the platelet reactivity-guided use of ticagrelor in combination with 200 mg aspirin, compared with standard antiplatelet regimen, improves clinical outcome in moderate to high-risk STEMI patients undergoing PPCI.

Clinical trial registration: U.S. National Institutes of Health (NIH) at www.clinicaltrials.gov. ClinicalTrials.gov Identifier: NCT01739556, and Current Controlled Trials at www.controlledtrials.com. International Standard Randomized Controlled Trial Number ISRCTN83081599.