Abstract 2780: Effects of Apadenoson, a Selective Adenosine A2a Receptor Agonist for Myocardial Perfusion Imaging, on Coronary Blood Flow Velocity in Conscious Patients
Background: Apadenoson (APA) is a highly selective adenosine (ADO) A2a receptor agonist with potential utility for pharmacologic stress myocardial perfusion imaging. This study determined APA effects on coronary blood flow velocity (CBFV) compared to intravenous (IV) and intracoronary (IC) ADO.
Methods: CBFV was measured in conscious patients (pts) after coronary angiography using a 0.014“ Doppler wire in vessels with <40% stenosis. Escalating doses of IC ADO were used to determine peak hyperemic effect (Max-CBFV). For APA, reserve CBFV (CBFV-R) = [drug-induced CBFV]/[baseline CBFV] and normalized CBFV (%Max-CBFV) = [drug-induced CBFV/baseline]/[IC ADO-induced CBFV/baseline CBFV] were calculated. Group 1 pts received 0.5 (n=15), 1.0 (n=34), 2.0 (n=39), and/or 2.5 (n=21) μg/kg IV bolus APA. Group 2 (n=14) Pts received crossover administration of IV infusion ADO 140 ug/kg/min for 6 minutes, then 1.0 μg/kg APA.
Results: Group 1: In the table⇓, CBFV results are shown as peak effect ± 95% confidence interval; vital signs are % change (CH) ± standard deviation. All bolus APA doses produced hyperemia in ≤1 minute. Mean CBFV-R remained >2 times baseline values for 3, 6, 7, and 8 minutes for the 0.5, 1.0, 2.0, and 2.5 μg/kg doses, respectively. Group 2: CBFV produced by IV APA 1.0 μg/kg was very similar to IV ADO in extent ( ≈75– 80% Max-CBFV) and duration. The APA-induced effect persisted for ≈5 minutes.
Conclusion: IV APA produces prompt and marked increase in CBFV lasting several minutes. Its effects appear comparable to those produced by IV ADO without significant adverse hemodynamic effects. These data support the use of APA as a pharmacologic agent for myocardial perfusion imaging.