Background In patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, ischemic postconditioning has been shown to reduce infarct size, but the effect on clinical outcome has not been tested in a large randomized trial. In addition, deferring stent implantation in the infarct-related lesion 1 to 3 days after acute opening of the infarct-related artery could have protective effects, by reducing the risk of injury caused by distal embolization and microvascular obstruction. Finally, a considerable fraction of patients present with lesions in other coronary artery branches than the infarct-related artery. Whether a strategy of complete or partial revascularization of these patients should be preferred remains uncertain. Study design The DANAMI 3 trial program was designed to investigate 3 different randomized treatment strategies in patients with ST-segment elevation myocardial infarction: (1) ischemic postconditioning versus conventional treatment with a primary end point of death and hospitalization for heart failure; (2) deferring stent implantation in the infarct-related lesion versus conventional treatment with a primary end point of death, hospitalization for heart failure, reinfarction, and repeat revascularization; and (3) treatment of the culprit lesion only versus fractional flow reserve-guided complete revascularization in patients with multivessel disease, with a primary end point of death, reinfarction, and repeat revascularization. Summary The DANAMI 3 trial program will determine whether either of 2 approaches to reduce reperfusion injury and distal microvascular obstruction with postconditioning or deferred stent implantation will translate into improved clinical outcome and whether patients with multivessel disease undergoing primary percutaneous coronary intervention will benefit from a strategy of complete or partial revascularization.