Impact of a regimented aminophylline administration protocol on the burden of regadenoson-induced ischemia detected by SPECT myocardial perfusion imaging.

BACKGROUND

In patients undergoing regadenoson SPECT myocardial perfusion imaging (MPI), it is unknown how soon and at which dose intravenous aminophylline can be administered to reverse regadenoson-related adverse effects without blunting stress-induced myocardial ischemia.

METHODS AND RESULTS

We analyzed the pooled database of the ASSUAGE and ASSUAGE-CKD trials (n = 548). These were double-blinded, placebo-controlled, randomized clinical trials in which 75 mg of aminophylline or placebo was administered intravenously 90 seconds following Tc-tetrofosmin injection. There were no statistically significant differences in summed difference score (SDS) burden (P = .87) and in the rates of myocardial ischemia (SDS ≥ 2) (P = .93) between the aminophylline (n = 274) and placebo (n = 274) groups. There was no interaction between aminophylline use and SDS as a determinant of the composite endpoint of cardiac death or MI (P = .32) or the composite endpoint of cardiac death, MI, or coronary revascularization (P = .92).

CONCLUSION

In patients undergoing regadenoson-stress SPECT-MPI, the intravenous administration of 75 mg of aminophylline as early as 90 seconds after radioisotope injection does not seem to attenuate the burden of myocardial ischemia.