title: Regadenoson for myocardial perfusion scintigraphy.
abstract: BACKGROUND
  Stress myocardial perfusion scintigraphy (MPS) plays a major role in the detection of obstructive coronary artery disease and provides valuable diagnostic and prognostic information to guide clinical decision-making with regard to medical therapy and coronary revascularisation. Current stress techniques for MPS are effective but their use may be limited by reduced tolerability, contraindications and untoward side effects. The recently developed selective adenosine A2A receptor agonists have the potential for improving stress tolerability, hence expanding the indications for functional imaging in the assessment of coronary artery disease.
  
  
  METHODS
  This article reviews the basic principles underlying activation of coronary arteriolar adenosine A2A receptors. It describes the benefits and limitations of current vasodilator stress agents and highlights the effectiveness, side effect profile and tolerability of regadenoson, the only selective adenosine A2A receptor agonist available at present for clinical use.
  
  
  RESULTS
  The reader will gain an understanding of the pharmacokinetics and mechanism of action of regadenoson for the assessment of coronary artery disease when combined with myocardial perfusion imaging. The reader will also become aware of the available evidence on the clinical usefulness of regadenoson MPS and its future applications.
  
  
  CONCLUSIONS
  Selective activation of coronary arteriolar adenosine A2A receptors by regadenoson provides an effective modality of stress for the detection of inducible perfusion abnormality in patients with known or suspected coronary disease. The effectiveness of regadenoson is similar to that of adenosine, but test tolerability is improved with regadenoson. The use of this agent simplifies stress testing and has the potential for expanding the applications of functional imaging to patient populations unsuitable for conventional vasodilator stress with adenosine or dipyridamole.
authors.affiliation: National Heart and Lung Institute, Imperial College, London SW7 2AZ, UK.
authors.forename: Eliana
authors.initials: E
authors.lastname: Reyes
authors.forename: Dudley J
authors.initials: DJ
authors.lastname: Pennell