Abstract 16882: Comparison of Regadenoson and Adenosine in First Pass Quantitative Perfusion Cardiovascular Magnetic Resonance in Subjects With Suspected Coronary Microvascular Disease

Abstract

Introduction: Regadenoson and adenosine are commonly used vasodilators in myocardial perfusion imaging for detection of coronary artery disease. There are no comparative studies of the vasodilator properties of two agents in subjects with suspected coronary microvascular disease (CMD). We aimed to compare the potency of two vasodilators by quantifying myocardial perfusion in subjects with suspected CMD. Methods: Subjects with angina and more than two risk factors for CMD (females, or males with diabetes, metabolic syndrome, HTN, hyperlipidemia, and smoking) who had no obstructive coronary disease by invasive coronary angiography or CT angiography were enrolled for first-pass perfusion images using dual sequence. Stress perfusion images were acquired on 1.5T or 3.0T GE Healthcare during adenosine infusion or regadenoson. Rest perfusion images were acquired either 10 minutes following the cessation of adenosine or reversal with aminophylline. Myocardial blood flow (MBF) in ml/min/g and myocardial perfusion reserve (MPR) were quantified using Fermi deconvolution. Results: A total of thirty-two subjects were recruited with a mean age of 62±11 years, 53% men, history of hypertension in 91%, diabetes in 72%, hyperlipidemia in 75%, and tobacco use in 16%. Twenty (63%) of subjects underwent adenosine, while twelve (38%) of subjects underwent regadenoson. Regadenoson produced similar stress MBF compared to adenosine (2.30 ± 0.54 vs. 2.35 ± 0.61 ml/min/g, p = 0.66). Rest MBF was higher in the regadenoson group compared to adenosine group (1.35±0.35 vs. 1.12±0.26 ml/min/g, p=0.07). MPR was non-significantly lower in regadenoson compared to adenosine 1.72±0.70 vs.1.89±0.53 ml/g/min, p=0.13). Conclusions: Based on fully quantitative perfusion using CMR, regadenoson and adenosine have similar vasodilator efficacy in subjects with risk factors for CMD. However, resting blood flows are slightly higher when regadenoson is used which may impact quantification of MPR.