Excerpt

Since its approval by the Food and Drug Administration in April of 2008, regadenoson has enjoyed a wide implementation by nuclear cardiology laboratories. Presently, it is the preferred vasodilator stress agent in the United States, being used in 8 out of 10 pharmacologic stress SPECT myocardial perfusion imaging (MPI) studies.1 The initial approval of regadenoson was based on two phase 3 ADVANCE-MPI trials, in which regadenoson was demonstrated to produce perfusion defects similar to those induced by standard 6 minute adenosine infusion.2,3 Although diagnostic noninferiority of regadenoson was effectively demonstrated, prognostic noninferiority was beyond the scope of the ADVANCE-MPI trials. Nonetheless, given the similarity in perfusion images, the prognostic value of regadenoson stress was presumed to parallel that of adenosine. …