Intravenous Regadenoson Versus Intravenous Adenoscan® for Fractional Flow Reserve (FFR)

Testing will be completed during a Left Heart Catheterization (LHC). The first 48 eligible patients enrolled will receive an initial infusion of IV Adenoscan® through a peripheral vein at 140 mcg/kg/min. FFR measurements will be obtained utilizing a coronary pressure guide wire once peak hyperemia has been achieved. It takes about 84 seconds to reach peak hyperemia with Adenoscan®. Subsequently, these subjects will receive a dose of regadenoson at 0.4 mg through the same peripheral access site. FFR measurements will be obtained once peak hyperemia is achieved, which takes less than 30 seconds with regadenoson. Patients who react to either medication will be supported conservatively under close scrutiny.