Pharmacologic Stress Using Selective A2A Adenosine Receptor Agonists

Abstract

Adenosine and dipyridamole are nonselective A2A adenosine receptor agonists that provide reproducible coronary vasodilation thereby inducing flow disparities in the setting of physiologically important coronary stenosis. Although myocardial perfusion imaging in conjunction with pharmacologic stress with both agents has yielded high diagnostic accuracy and overall safety, limitations include concerns in selected populations, such as those with bronchospastic lung disease and heart block, frequent side effects, and a complicated method of delivery (sustained intravenous infusion). Regadenoson, binodenoson, and apadenoson are selective A2A adenosine receptor agonists that have been shown to provide more selective coronary vasodilatation, with improved safety profiles and patient tolerability. Additionally, these new agents may be delivered by an intravenous bolus eliminating the requirement for an infusion pump. Regadenoson is already in widespread clinical use in the United States. Binodenoson completed phase 3 clinical trials but has not yet been approved for clinical use. Apadenoson is currently in pivotal phase 3 clinical trials.