title: Regadenoson pharmacologic stress for myocardial perfusion imaging: a three-way comparison between regadenoson administered at peak exercise, during walk recovery, or no-exercise.
abstract: BACKGROUND
  Regadenoson (Reg) is being administered with increasing frequency either at peak exercise (ExPeak-Reg) or during a slow-down/walking recovery state (ExRec-Reg) rather than at rest (Rest-Reg). The aim of this study was to compare the clinical response of ExPeak-Reg, ExRec-Reg, and Rest-Reg.
  
  
  METHODS
  We compared 531 patients divided equally between Rest-Reg, ExPeak-Reg, and ExRec-Reg matched for age, sex, and BMI.
  
  
  RESULTS
  The average systolic blood pressure (SBP) rise following Reg was modest, but there was considerable heterogeneity and the ExPeak-Reg group had a higher percentage of patients who had a SBP rise of 40 mm Hg or a fall of 20 mm Hg than either the ExRec-Reg or the Rest-Reg groups (≥40 mm Hg rise 6.8%, 1.7%, and 1.7%, respectively) (P < .02) (≥20 mm Hg fall 15.8%, 13.0%, and 7.3%, respectively) (P < .05). Chest discomfort, nausea, dizziness, and interfering abdominal radiotracer activity were less common in both exercise Reg groups compared to Rest-Reg (P < .05).
  
  
  CONCLUSIONS
  Regadenoson injected at peak of symptom-limited exercise was generally well tolerated, but some patients had a significant rise or drop in SBP. There is no apparent advantage of administering regadenoson at peak exercise rather than during walk recovery, and the latter approach may have a greater safety margin.
authors.affiliation: Saint-Luke's Mid America Heart Institute, 4330 Wornall Road, Suite 2000, Kansas City, MO 64111, USA. rthompson@cc-pc.com
authors.forename: Randall C
authors.initials: RC
authors.lastname: Thompson
authors.forename: Harshal
authors.initials: H
authors.lastname: Patil
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Thompson
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Thomas
authors.forename: Mohammed
authors.initials: M
authors.lastname: Al-Amoodi
authors.forename: Kevin F
authors.initials: KF
authors.lastname: Kennedy
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Bybee
authors.forename: A
authors.initials: A
authors.lastname: Iain McGhie
authors.forename: James H
authors.initials: JH
authors.lastname: O'Keefe
authors.forename: Lisa
authors.initials: L
authors.lastname: Oakes
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Bateman
mesh_terms: D058908:Adenosine A2 Receptor Agonists; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D010807:Physical Endurance; D015995:Prevalence; D011687:Purines; D011720:Pyrazoles; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data; D014665:Vasodilator Agents; D016138:Walking
chemical_list: D058908:Adenosine A2 Receptor Agonists; D011687:Purines; D011720:Pyrazoles; D014665:Vasodilator Agents; C430916:regadenoson