Quantitative myocardial perfusion response to adenosine and regadenoson in patients with suspected coronary artery disease

Background The aim of the present study was to compare the quantitative flow responses of regadenoson against adenosine using cardiac 15 O-water PET imaging in patients with suspected or known coronary artery disease (CAD). Methods Hyperemic myocardial blood flow (MBF) after adenosine and regadenoson was compared using correlation and Bland–Altman analysis in 21 patients who underwent rest and adenosine 15 O-water PET scans followed by rest and regadenoson 15 O-water PET scans. Results Global mean (± SD) MBF values at rest and stress were 0.92 ± 0.27 and 2.68 ± 0.80 mL·g·min for the adenosine study and 0.95 ± 0.29 and 2.76 ± 0.79 mL·g·min for the regadenoson study ( P = 0.55 and P = 0.49). The correlations between global and regional adenosine- and regadenoson-based stress MBF were strong ( r = 0.80 and r = 0.77). The biases were small for both global and regional MBF comparisons (0.08 and 0.09 mL·min·g), but the limits of agreement were wide for stress MBF. Conclusion The correlation between regadenoson- and adenosine-induced hyperemic MBF was strong but the agreement was only moderate indicating that established cut-off values for 15 0-water PET should be used cautiously if using regadenoson as vasodilator.