The REOPEN-AMI will be a placebo-controlled, randomized, open label, blind-examination (PROBE), multicenter, trial of the effects of intracoronary adenosine or nitroprusside on coronary reflow in patients undergoing primary or rescue PCI and thrombus-aspiration. The recruiting period comprises 1 year time between January 2008 and December 2008. During the last months, the others participating centres in Italy, were contacted and entered in the study after agreement. As result prospective recruitment should start at the same time in all participating centers. Each center, to be activated for the study, had to warrant (fully describing the search process as well as the characteristics of the internal database) ability to provide detailed data regarding all the patients.