Adverse events profile of regadenoson in patients with end-stage lung disease candidates for lung transplantation

Background Regadenoson is a selective agonist of A2A adenosine receptors, and thus the risk of bronchoconstriction due to the activity through the A2B and A3 receptors is much lower, and several studies support its use in patients with mild to severe chronic obstructive pulmonary disease (COPD). Purpose We aim to assess the safety of regadenoson, combined with low-level exercise in patients with end-stage lung disease (ELD) who were considered candidates for lung transplantation (LT), referred for myocardial perfusion imaging (MPI). Methods We studied prospectively 14 patients (71.4% male, mean age: 55.5± years, range: 35-62 years) with ELD who met LT criteria. Stress was 4 minutes of low-level exercise with bolus injection of regadenoson (0.4 mg) at minute 1.5, followed by 99mTc-MPI agent injection. Type of ELD, pulmonary function test (forced vital capacity (FVC), forced expiratory volume in 1 seconds (FEV1), FEV1/FVC, diffusing capacity (DLCO), and carbon monoxide transfer coefficient (KCO)), respiratory treatment, adverse events, oxygen saturation (SatO2), changes in systolic blood pressure (SBP), and heart rate (HR), were registered. Results The primary diagnoses included idiopathic pulmonary fibrosis (n=7), severe COPD GOLD IV (n=5), and diffuse interstitial lung disease (n=2) (50.0%, 35.7% and 14.3%, respectively). 64.3% showed a restrictive spirometric pattern (33.3% mild, moderate and severe grades, respectively) and 35.7% a mixed obstrucitve pattern (80% severe, 20% moderate). The observed adverse events profile of regadenoson was self-limiting: Dyspnea (50.0%), fatigue (35.7%), nausea (14.3%), dizziness and feeling hot (7.1%, respectively). One patient needed additional oxygen (4 L/min) because of severe dyspnea. 28.6% of patients did not report any symptom. We observed no significant changes in SBP (139.9 mmHg ± 16.5 vs 149.0 mmHg ± 26.1; p=0.15). Mean HR increased significantly from baseline (77 b.p.m. ± 10 vs 114 b.p.m. ± 14; p<0.05). Conclusions Regadenoson combined with low-level exercise is safe in patients with ELD who can benefit from coronary revascularization before lung transplantation.