Slow-flow phenomena is observed around 15% of patients undergoing PPCI and has been associated with poor prognosis. Hyperemic drugs, such as nitroprussiate and adenosine, have not yet demonstrated to reduce the infarct size and prognosis in patients with slow flow. Controlled flow-mediated hyperemia using a dedicated catheter for intracoronary saline infusion has been shown to stimulate microcirculatory vasodilatation in stable patients similarly as hyperemic drugs.~The aims of the study are to compare the absolute microcirculatory resistance of the infarct-related artery presenting with slow flow after PPCI, as assessed by intracoronary thermo-dilution, treated with standard pharmacologic hyperemia versus flow-mediated hyperemia; and to compare the angiographic TIMI frame count after treatment of slow flow phenomena with the two investigated strategies.
A total of 100 patients with ST-elevation myocardial infarction (STEMI) presenting slow-flow after primary-percutaneous coronary intervention (PPCI) will be randomized to pharmacologic treatment with hyperemic drugs versus flow-mediated hyperemia.