Adenoscan® (adenosine) is an approved pharmacological stress agent indicated as an adjunct to thallium-201 myocardial perfusion scintigraphy in patients unable to exercise adequately. The investigational drug, regadenoson (CVT-3146) is a selective A2A adenosine receptor agonist, the receptor responsible for coronary vasodilation, and is being studied for potential use as a pharmacologic stress agent in myocardial perfusion imaging (MPI) studies. This study will compare the safety and efficacy of regadenoson to that of Adenoscan in detecting reversible myocardial perfusion defects.

ADVANCE MPI 2 is a multi-national, double-blind, randomized, active-controlled, parallel group clinical trial to evaluate the safety and efficacy of regadenoson in SPECT MPI compared to that of the approved pharmacological stress agent, Adenoscan. Patients referred for a clinically indicated pharmacological stress MPI study will be eligible for enrollment. The trial is designed: (1) to compare the pharmacological stress SPECT images obtained with regadenoson to those obtained with Adenoscan, and (2) to compare the safety and tolerability of the two stress agents.

Inclusion Criteria:

• Referred for a clinically indicated pharmacological stress SPECT myocardial perfusion imaging study

Exclusion Criteria:

• Any condition precluding the safe administration of Adenoscan for a SPECT myocardial perfusion imaging study
• Pregnant or breast-feeding, or (if pre-menopausal), not practicing acceptable method of birth control