title: A strategy of symptom-limited exercise with regadenoson-as-needed for stress myocardial perfusion imaging: a randomized controlled trial.
abstract: BACKGROUND
  Ambulatory patients with uncertain functional capacity may benefit from combined exercise and vasodilator stress protocols for myocardial perfusion imaging (MPI). The safety and MPI image quality with regadenoson administered during symptom-limited exercise have not been prospectively evaluated.
  
  
  RESULTS
  A total of 140 patients (mean age 61 years, 48% female) referred for exercise with vasodilator stress MPI were randomized 2:1 to a strategy of exercise with regadenoson-as-necessary (Ex-Reg, n = 96) or dipyridamole with exercise (Dip-Ex, n = 44) after Duke Activity Status Index (DASI) scoring (median score 28 vs 24, P = .09). Ex-Reg subjects commenced treadmill exercise and regadenoson was administered only if the subject was unable to reach standard endpoints. Dip-Ex subjects received dipyridamole prior to symptom-limited exercise. Hemodynamics were recorded throughout. Subjects completed symptom questionnaires and MPI image quality was assessed by blinded read. Ex-Reg subjects were more likely to achieve ≥85% age-predicted maximum heart rate than Dip-Ex subjects (57% vs 32%, P < .01). Only 50% of subjects meeting inclusion criteria and randomized to Ex-Reg required regadenoson and none had symptomatic hemodynamic changes. Severe side effects or adverse events occurred in 16% of Ex-Reg and 24% of Dip-Ex subjects (P = .12). MPI image quality was "good" or "excellent" in 88% of Ex-Reg subjects and 86% of Dip-Ex subjects (P = .33).
  
  
  CONCLUSIONS
  A strategy of exercise with regadenoson-as-needed for MPI offers similar safety and side effect profile with similar image quality compared to dipyridamole with exercise, with reduced pharmaceutical use.
authors.affiliation: Division of Cardiology, Department of Medicine, University of Connecticut School of Medicine, Farmington, CT, USA. mwparker@harthosp.org
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Parker
authors.forename: Donna Chelle
authors.initials: DC
authors.lastname: Morales
authors.forename: Hanna B
authors.initials: HB
authors.lastname: Slim
authors.forename: Alan W
authors.initials: AW
authors.lastname: Ahlberg
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Katten
authors.forename: Giselle
authors.initials: G
authors.lastname: Cyr
authors.forename: Shishir
authors.initials: S
authors.lastname: Mathur
authors.forename: Afrooz
authors.initials: A
authors.lastname: Ardestani
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Barmpouletos
authors.forename: Geeta Swamy
authors.initials: GS
authors.lastname: Iyah
authors.forename: Steven M
authors.initials: SM
authors.lastname: Borer
authors.forename: Gary V
authors.initials: GV
authors.lastname: Heller
mesh_terms: D058908:Adenosine A2 Receptor Agonists; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011687:Purines / Q000009:adverse effects; D011720:Pyrazoles / Q000009:adverse effects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014665:Vasodilator Agents
chemical_list: D058908:Adenosine A2 Receptor Agonists; D011687:Purines; D011720:Pyrazoles; D014665:Vasodilator Agents; C430916:regadenoson