Background

The aim of the present study was to compare the quantitative flow responses of regadenoson against adenosine using cardiac O-15-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 O-15-water PET scans followed by rest and regadenoson O-15-water PET scans.

Results

Global mean (+/- SD) MBF values at rest and stress were 0.92 +/- 0.27 and 2.68 +/- 0.80 mL center dot g center dot min for the adenosine study and 0.95 +/- 0.29 and 2.76 +/- 0.79 mL center dot g center dot 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 center dot min center dot 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)o-water PET should be used cautiously if using regadenoson as vasodilator.