Abstract
Regadenoson is an increasingly used pharmacological stress agent for myocardial perfusion imaging (MPI) that has an important advantage over other primary coronary vasodilators. Both adenosine and dipyridamole have a non-selective action on the adenosine receptors and can therefore induce bronchospasm in susceptible individuals. In contrast, regadenoson acts selectively on the adenosine receptor subtype responsible for the coronary vasodilator effect of these agents with little, if any, activity on adenosine receptor-mediated bronchoconstrictive pathways. This gives regadenoson an advantage over other vasodilators in the management of patients with obstructive airways disease undergoing stress MPI. There is compelling evidence for the improved tolerability of regadenoson stress in patients with a history of bronchial hyperreactivity. Moreover, regadenoson has proved to be safe in advanced forms of lung disease and is currently the preferred stress agent in these patients. Experience on the use of regadenoson in poorly controlled asthma or chronic obstructive pulmonary disease (COPD) is limited, and thus caution must be exercised when considering regadenoson stress in patients with suspected persistent or clinically manifest airway obstruction.
