title: Attenuation of adenosine-induced myocardial perfusion heterogeneity by atenolol and other cardioselective beta-adrenoceptor blockers: a crossover myocardial perfusion imaging study.
abstract: Little is known about the effect of chronic beta-blockade on adenosine actions. We sought to investigate the effect of oral beta-blockers on the presence, extent, and severity of myocardial perfusion abnormality induced by adenosine in patients with coronary artery disease.
  
  
  METHODS
  In this crossover study, 45 male patients with coronary artery disease on beta-blocker therapy with atenolol, bisoprolol, or metoprolol underwent adenosine myocardial perfusion imaging both on and off beta-blockade in a random order on separate days. Myocardial perfusion was assessed both qualitatively and quantitatively. Hemodynamic response, image analysis, and sensitivity for the detection of coronary stenosis (>or=50% luminal diameter reduction on x-ray coronary angiography) were compared between the on and off beta-blocker studies.
  
  
  RESULTS
  Rate pressure product both at baseline and at peak adenosine infusion decreased by 23% +/- 15% and 21% +/- 18%, respectively, after beta-blockade (P < 0.001 for all). The median (interquartile range) summed difference score, a measure of defect reversibility, and quantitative defect size were both significantly lower after beta-blockade (median, 7.0 [interquartile range, 2.0-9.5] vs. median, 5.0 [interquartile range, 0-8.0], P = 0.002; and quantitative defect size, 18% [interquartile range, 9%-34%] vs. quantitative defect size, 6% [interquartile range, 0%-19%], P < 0.001, respectively). The overall sensitivity for the detection of coronary stenosis decreased from 0.76 (95% confidence interval, 0.65-0.88) to 0.58 (95% confidence interval, 0.45-0.71) after beta-blockade (P = 0.03).
  
  
  CONCLUSIONS
  beta-blockade causes a small but significant reduction in the extent and severity of perfusion abnormality by adenosine. This may reduce the diagnostic sensitivity of adenosine myocardial perfusion imaging for the detection of flow-limiting coronary stenosis.
authors.affiliation: National Heart and Lung Institute, Imperial College London, London, United Kingdom. e.reyes@rbht.nhs.uk
authors.forename: Eliana
authors.initials: E
authors.lastname: Reyes
authors.forename: James
authors.initials: J
authors.lastname: Stirrup
authors.forename: Michael
authors.initials: M
authors.lastname: Roughton
authors.forename: Savio
authors.initials: S
authors.lastname: D'Souza
authors.forename: S Richard
authors.initials: SR
authors.lastname: Underwood
authors.forename: Constantinos
authors.initials: C
authors.lastname: Anagnostopoulos
mesh_terms: D000241:Adenosine / Q000009:adverse effects* / Q000037:antagonists & inhibitors*; D000319:Adrenergic beta-Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D000368:Aged; D001262:Atenolol / Q000009:adverse effects / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging; D018592:Cross-Over Studies; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D015899:Tomography, Emission-Computed, Single-Photon; D014665:Vasodilator Agents / Q000009:adverse effects* / Q000037:antagonists & inhibitors*
chemical_list: D000319:Adrenergic beta-Antagonists; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D014665:Vasodilator Agents; C078700:technetium tc-99m tetrofosmin; D001262:Atenolol; D000241:Adenosine