Safety of regadenoson as a pharmacologic stress agent for myocardial perfusion imaging in chronic kidney disease patients not on hemodialysis

Background: Pharmacokinetic studies suggest delayed clearance of Regadenoson (REG), a new selective A2A receptor agonist in chronic kidney disease (CKD). The safety of REG in large series of CKD patients in daily clinical practice remains unstudied. Methods: Retrospective study of patients with eGFR < 60 mL/min (n = 411, Grp 1, CKD) were compared to patients with eGFR ≥ 60 mL/min (n = 638, Grp 2, Control) undergoing REG-SPECT from Jan to Nov 2009. Patient demographics, REG-SPECT data, side effects, and arrhythmia occurrences were evaluated. Results: No major adverse events were noted immediately after REG-SPECT or at 1 week of follow-up. There were no differences in any arrhythmias in between the two groups (Grp 1, 47.2% vs Grp 2, 42.9%, P = ns). Ninety-nine percent of arrhythmias in CKD patients were PACs or PVCs. Transient junctional rhythm was observed in one CKD patient. There were no occurrences of second degree or higher degree AV block. Grp 1 had a blunted heart rate response (16.6 ± 16.1 vs 24.9 ± 20.3 bpm, P ≤ .001) and greater systolic blood pressure drop response (-7.4 ± 21.1 vs -1.4 ± 20.9 mm Hg, P ≤ .001) compared to Grp 2. Transient headache was more in Grp 2 (15.8% vs 22.6%, P ≤ .007). Aminophylline use to ward-off the side effects was comparable (9.5% vs 9.9%, P = ns). Conclusion: REG-SPECT can be safely performed in CKD non-dialysis patients with excellent tolerability, minimal side effects, and favorable hemodynamic responses compared to control group.